check_mk_agent.linux

#!/bin/bash
# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
# conditions defined in the file COPYING, which is part of this source code package.

#
# BEGIN COMMON AGENT CODE
#

usage() {
    cat <<HERE
Usage: ${0} [OPTION...]

The Checkmk agent to monitor *nix style systems.

Options:
  -h, --help                 show this message and exit
  -d, --debug                emit debugging messages
  -p, --profile              create files containing the execution times
  --force-inventory          get the output of the agent plugin 'mk_inventory'
                             independent of the last run state.
HERE
}

inpath() {
    # replace "if type [somecmd]" idiom
    # 'command -v' tends to be more robust vs 'which' and 'type' based tests
    command -v "${1:?No command to test}" >/dev/null 2>&1
}

get_file_atime() {
    stat -c %X "${1}" 2>/dev/null ||
        stat -f %a "${1}" 2>/dev/null ||
        perl -e 'if (! -f $ARGV[0]){die "0000000"};$atime=(stat($ARGV[0]))[8];print $atime."\n";' "${1}"
}

get_file_mtime() {
    stat -c %Y "${1}" 2>/dev/null ||
        stat -f %m "${1}" 2>/dev/null ||
        perl -e 'if (! -f $ARGV[0]){die "0000000"};$mtime=(stat($ARGV[0]))[9];print $mtime."\n";' "${1}"
}

is_valid_plugin() {
    # test if a file is executable and does not have certain
    # extensions (remnants from distro upgrades).
    case "${1:?No plugin defined}" in
        *.dpkg-new | *.dpkg-old | *.dpkg-temp | *.dpkg-tmp) return 1 ;;
        *) [ -f "${1}" ] && [ -x "${1}" ] ;;
    esac
}

set_up_process_commandline_arguments() {
    while [ -n "${1}" ]; do
        case "${1}" in
            -d | --debug)
                set -xv
                DISABLE_STDERR=false
                shift
                ;;

            -p | --profile)
                LOG_SECTION_TIME=true
                # disable caching to get the whole execution time
                DISABLE_CACHING=true
                shift
                ;;

            --force-inventory)
                export MK_FORCE_INVENTORY=true
                shift
                ;;

            -h | --help)
                usage
                exit 1
                ;;

            *)
                shift
                ;;
        esac
    done
}

set_up_get_epoch() {
    # On some systems date +%s returns a literal %s
    if date +%s | grep "^[0-9].*$" >/dev/null 2>&1; then
        get_epoch() { date +%s; }
    else
        # do not check whether perl is even present.
        # in weird cases we may be fine without get_epoch.
        get_epoch() { perl -e 'print($^T."\n");'; }
    fi
}

set_up_current_shell() {
    # Note the current shell may not be the same as what is specified in the
    # shebang, e.g. when reconfigured in the xinetd/systemd/whateverd config file
    CURRENT_SHELL="$(ps -o args= -p $$ | cut -d' ' -f1)"
}

#
# END COMMON AGENT CODE
#

set_variable_defaults() {
    # some 'booleans'
    [ "${MK_RUN_SYNC_PARTS}" = "false" ] || MK_RUN_SYNC_PARTS=true
    [ "${MK_RUN_ASYNC_PARTS}" = "false" ] || MK_RUN_ASYNC_PARTS=true

    # WATCH OUT: These 5 lines are searched for and replaced by the
    # agent bakery!
    # TODO: CMK-8339 (proper configuration)
    : "${MK_LIBDIR:="/usr/lib/check_mk_agent"}"
    : "${MK_CONFDIR:="/etc/check_mk"}"
    : "${MK_VARDIR:="/var/lib/check_mk_agent"}"
    : "${MK_LOGDIR:="/var/log/check_mk_agent"}"
    : "${MK_BIN:="/usr/bin"}"

    export MK_LIBDIR
    export MK_CONFDIR
    export MK_VARDIR
    export MK_LOGDIR
    export MK_BIN

    # Optionally set a tempdir for all subsequent calls
    #export TMPDIR=

    # All executables in PLUGINSDIR will simply be executed and their
    # ouput appended to the output of the agent. Plugins define their own
    # sections and must output headers with '<<<' and '>>>'
    PLUGINSDIR=${MK_LIBDIR}/plugins

    # All executables in LOCALDIR will by executabled and their
    # output inserted into the section <<<local>>>. Please
    # refer to online documentation for details about local checks.
    LOCALDIR=${MK_LIBDIR}/local

    # All files in SPOOLDIR will simply appended to the agent
    # output if they are not outdated (see below)
    SPOOLDIR=${MK_VARDIR}/spool
}

set_up_path() {
    _PATH="${1}"
    # Make sure that locally installed binaries are found
    # Only add binaries if they are not already in the path! If you append to path in a loop the process will
    # eventually each the 128k size limit for the environment and become a zombie process. See execve manpage.
    [ "${_PATH#*"/usr/local/bin"}" != "${_PATH}" ] || _PATH="${_PATH}:/usr/local/bin"
    [ -n "${MK_BIN}" ] && { [ "${_PATH#*"${MK_BIN}"}" != "${_PATH}" ] || _PATH="${_PATH}:${MK_BIN}"; }
    [ -d "/var/qmail/bin" ] && { [ "${_PATH#*"/var/qmail/bin"}" != "${_PATH}" ] || _PATH="${_PATH}:/var/qmail/bin"; }
    echo "${_PATH}"
    unset _PATH
}

set_up_remote() {
    # Provide information about the remote host. That helps when data
    # is being sent only once to each remote host.
    REMOTE="${REMOTE_HOST:-"${REMOTE_ADDR:-"${SSH_CLIENT%% *}"}"}"

    # If none of the above are set *and* we are configured to, try to read it from stdin
    [ -z "${REMOTE}" ] && [ "${MK_READ_REMOTE}" = "true" ] && read -r REMOTE

    export REMOTE
}

announce_remote() {
    # let RTCs know about this remote
    [ -d "${MK_VARDIR}/rtc_remotes" ] || mkdir "${MK_VARDIR}/rtc_remotes"
    [ -n "${REMOTE}" ] && [ "${REMOTE}" != "push-connection" ] && touch "${MK_VARDIR}/rtc_remotes/${REMOTE}"
}

#
# BEGIN COMMON AGENT CODE
#

# SC2089: Quotes/backslashes will be treated literally. Use an array.
# shellcheck disable=SC2089
MK_DEFINE_LOG_SECTION_TIME='_log_section_time() { "$@"; }'
finalize_profiling() { :; }

set_up_profiling() {

    PROFILING_CONFIG="${MK_CONFDIR}/profiling.cfg"
    if [ -e "${PROFILING_CONFIG}" ]; then
        # Config vars:
        #   LOG_SECTION_TIME=true/false
        #   DISABLE_CACHING=true/false

        # If LOG_SECTION_TIME=true via profiling.cfg do NOT disable caching in order
        # to get the real execution time during operation.
        # shellcheck disable=SC1090
        . "${PROFILING_CONFIG}"
    fi

    PROFILING_LOGFILE_DIR="${MK_LOGDIR}/profiling/$(date +%Y%m%d_%H%M%S)"

    if ${LOG_SECTION_TIME:-false}; then
        mkdir -p "${PROFILING_LOGFILE_DIR}"
        agent_start="$(perl -MTime::HiRes=time -le 'print time()')"

        # SC2016: Expressions don't expand in single quotes, use double quotes for that.
        # SC2089: Quotes/backslashes will be treated literally. Use an array.
        # shellcheck disable=SC2016,SC2089
        MK_DEFINE_LOG_SECTION_TIME='_log_section_time() {
            section_func="$@"

            base_name=$(echo "${section_func}" | sed "s/[^A-Za-z0-9.-]/_/g")
            profiling_logfile="'"${PROFILING_LOGFILE_DIR}"'/${base_name}.log"

            start="$(perl -MTime::HiRes=time -le "print time()")"
            { time ${section_func}; } 2>> "${profiling_logfile}"
            echo "runtime $(perl -MTime::HiRes=time -le "print time() - ${start}")" >> "${profiling_logfile}"
        }'

        finalize_profiling() {
            pro_log_file="${PROFILING_LOGFILE_DIR}/profiling_check_mk_agent.log"
            agent_end="$(perl -MTime::HiRes=time -le 'print time()')"
            echo "runtime $(echo "${agent_end} - ${agent_start}" | bc)" >>"${pro_log_file}"
        }
    fi

    eval "${MK_DEFINE_LOG_SECTION_TIME}"
    # SC2090: Quotes/backslashes in this variable will not be respected.
    # shellcheck disable=SC2090
    export MK_DEFINE_LOG_SECTION_TIME
}

unset_locale() {
    # eliminate localized outputs where possible
    # The locale logic here is used to make the Python encoding detection work (see CMK-2778).
    unset -v LANG LC_ALL
    if inpath locale && inpath paste; then
        # match C.UTF-8 at the beginning, but not e.g. es_EC.UTF-8!
        case "$(locale -a | paste -sd ' ' -)" in
            *' C.UTF-8'* | 'C.UTF-8'*) LC_ALL="C.UTF-8" ;;
            *' C.utf8'* | 'C.utf8'*) LC_ALL="C.utf8" ;;
        esac
    fi
    LC_ALL="${LC_ALL:-C}"
    export LC_ALL
}

#
# END COMMON AGENT CODE
#

read_python_version() {
    if inpath "${1}"; then
        version=$(${1} -c 'import sys; print("%s.%s"%(sys.version_info[0], sys.version_info[1]))')

        major=${version%%.*}
        minor=${version##*.}

        if [ "${major}" -eq "${2}" ] && [ "${minor}" -ge "${3}" ]; then
            echo "${1}"
            return 0
        fi
    fi
    return 1
}

detect_python() {
    PYTHON3=$(read_python_version python3 3 4 || read_python_version python 3 4)
    PYTHON2=$(read_python_version python2 2 6 || read_python_version python 2 6)
    if [ -f "${MK_CONFDIR}/python_path.cfg" ]; then
        # shellcheck source=/dev/null
        . "${MK_CONFDIR}/python_path.cfg"
    fi
    export PYTHON2 PYTHON3

    if [ -z "${PYTHON2}" ] && [ -z "${PYTHON3}" ]; then
        NO_PYTHON=true
    elif [ -n "${PYTHON3}" ] && [ "$(
        ${PYTHON3} -c 'pass' >/dev/null 2>&1
        echo $?
    )" -eq 127 ]; then
        WRONG_PYTHON_COMMAND=true
    elif [ -z "${PYTHON3}" ] && [ "$(
        ${PYTHON2} -c 'pass' >/dev/null 2>&1
        echo $?
    )" -eq 127 ]; then
        WRONG_PYTHON_COMMAND=true
    fi
}

detect_container_environment() {
    if [ -f /.dockerenv ]; then
        IS_DOCKERIZED=1
    elif grep container=lxc /proc/1/environ >/dev/null 2>&1; then
        # Works in lxc environment e.g. on Ubuntu bionic, but does not
        # seem to work in proxmox (see CMK-1561)
        IS_LXC_CONTAINER=1
    elif grep 'lxcfs /proc/cpuinfo fuse.lxcfs' /proc/mounts >/dev/null 2>&1; then
        # Seems to work in proxmox
        IS_LXC_CONTAINER=1
    else
        unset IS_DOCKERIZED
        unset IS_LXC_CONTAINER
    fi

    if [ -n "${IS_DOCKERIZED}" ] || [ -n "${IS_LXC_CONTAINER}" ]; then
        if [ "$(stat -fc'%t' /sys/fs/cgroup)" = "63677270" ]; then
            IS_CGROUP_V2=1
            CGROUP_SECTION_SUFFIX="_cgroupv2"
        else
            unset IS_CGROUP_V2
            unset CGROUP_SECTION_SUFFIX
        fi
    fi
}

# Prefer (relatively) new /usr/bin/timeout from coreutils against
# our shipped waitmax. waitmax is statically linked and crashes on
# some Ubuntu versions recently.
if inpath timeout; then
    waitmax() {
        timeout "$@"
    }
fi

encryption_panic() {
    echo "<<<check_mk>>>"
    echo "EncryptionPanic: true"
    exit 1
}

set_up_encryption() {
    # shellcheck source=agents/cfg_examples/encryption.cfg
    [ -f "${MK_CONFDIR}/encryption.cfg" ] && {
        . "${MK_CONFDIR}/encryption.cfg" || encryption_panic
    }
    define_optionally_encrypt "${ENCRYPTED:-"no"}"
}

hex_decode() {
    # We might not have xxd available, so we have to do it manually.
    # Be aware that this implementation is very slow and should not be used for large data.
    local hex="$1"
    for ((i = 0; i < ${#hex}; i += 2)); do
        printf '%b' "\x${hex:i:2}"
    done
}

parse_kdf_output() {
    local kdf_output="$1"
    salt_hex=$(echo "$kdf_output" | grep -oP "(?<=salt=)[0-9A-F]+")
    key_hex=$(echo "$kdf_output" | grep -oP "(?<=key=)[0-9A-F]+")
    iv_hex=$(echo "$kdf_output" | grep -oP "(?<=iv =)[0-9A-F]+")
    # Make sure this rather brittle grepping worked. For example, some openssl update might decide
    # to remove that odd-looking space behind 'iv'.
    # Note that the expected LENGTHS ARE DOUBLED because the values are hex encoded.
    if [ ${#salt_hex} -ne 16 ] || [ ${#key_hex} -ne 64 ] || [ ${#iv_hex} -ne 32 ]; then
        encryption_panic
    fi
    echo "$salt_hex" "$key_hex" "$iv_hex"
}

encrypt_then_mac() {
    # Encrypt the input data, calculate a MAC over IV and ciphertext, then
    # print mac and ciphertext.
    local salt_hex="$1"
    local key_hex="$2"
    local iv_hex="$3"
    local ciphertext_b64

    # We need the ciphertext twice: for the mac and for the output. But we can only store it in
    # encoded form because it can contain null bytes.
    ciphertext_b64=$(openssl enc -aes-256-cbc -K "$key_hex" -iv "$iv_hex" | openssl enc -base64)

    (
        hex_decode "$iv_hex"
        echo "$ciphertext_b64" | openssl enc -base64 -d
    ) | openssl dgst -sha256 -mac HMAC -macopt hexkey:"$key_hex" -binary

    echo "$ciphertext_b64" | openssl enc -base64 -d
}

define_optionally_encrypt() {
    # if things fail, make sure we don't accidentally send unencrypted data
    unset optionally_encrypt

    if [ "${1}" != "no" ]; then
        OPENSSL_VERSION=$(openssl version | awk '{print $2}' | awk -F . '{print (($1 * 100) + $2) * 100+ $3}')
        #
        # Encryption scheme for version 04 and 05:
        #
        #   salt    <- random_salt()
        #   key, IV <- version_specific_kdf( salt, password )
        #
        #   ciphertext <- aes_256_cbc_encrypt( key, IV, message )
        #   mac        <- hmac_sha256( key, iv:ciphertext )
        #
        #   // The output blob is formed as:
        #   // - 2 bytes version
        #   // - optional: rtc timestamp
        #   // - 8 bytes salt
        #   // - 32 bytes MAC
        #   // - the ciphertext
        #   result <- [version:salt:mac:ciphertext]

        if [ "${OPENSSL_VERSION}" -ge 10101 ]; then
            optionally_encrypt() {
                # version: 05
                # kdf: pbkdf2, 600.000 iterations

                local salt_hex key_hex iv_hex
                read -r salt_hex key_hex iv_hex <<<"$(
                    parse_kdf_output "$(openssl enc -aes-256-cbc -md sha256 -pbkdf2 -iter 600000 -k "${1}" -P)"
                )"

                printf "05"
                printf "%s" "${2}"
                hex_decode "$salt_hex"
                encrypt_then_mac "$salt_hex" "$key_hex" "$iv_hex"
            }
        elif [ "${OPENSSL_VERSION}" -ge 10000 ]; then
            optionally_encrypt() {
                # version: 04
                # kdf: openssl custom kdf based on sha256

                local salt_hex key_hex iv_hex
                read -r salt_hex key_hex iv_hex <<<"$(
                    parse_kdf_output "$(openssl enc -aes-256-cbc -md sha256 -k "${1}" -P)"
                )"

                printf "04"
                printf "%s" "${2}"
                hex_decode "$salt_hex"
                encrypt_then_mac "$salt_hex" "$key_hex" "$iv_hex"
            }
        else
            optionally_encrypt() {
                printf "00%s" "${2}"
                openssl enc -aes-256-cbc -md md5 -k "${1}" -nosalt
            }
        fi
    else
        optionally_encrypt() {
            [ -n "${2}" ] && printf "99%s" "${2}"
            cat
        }
    fi

}

set_up_disabled_sections() {
    if [ -f "${MK_CONFDIR}/exclude_sections.cfg" ]; then
        # shellcheck source=agents/cfg_examples/exclude_sections.cfg
        . "${MK_CONFDIR}/exclude_sections.cfg"
    fi
}

export_utility_functions() {
    # At the time of writing of this function, the linux agent exports
    # some helper functions, so I consolidate those exports here.
    # I am not sure whether this is a good idea, though.
    # Their API is unstable.
    export -f run_mrpe
    export -f waitmax
    export -f run_cached
}

section_checkmk() {
    cat <<HERE
<<<check_mk>>>
Version: 2.4.0b1
AgentOS: linux
Hostname: $(uname -n)
AgentDirectory: ${MK_CONFDIR}
DataDirectory: ${MK_VARDIR}
SpoolDirectory: ${SPOOLDIR}
PluginsDirectory: ${PLUGINSDIR}
LocalDirectory: ${LOCALDIR}
HERE

    # try to find only_from configuration
    if [ -n "${REMOTE_HOST}" ]; then # xinetd
        sed -n "/^service[[:space:]]*check-mk-agent/,/}/s/^[[:space:]]*only_from[[:space:]]*=[[:space:]]*\(.*\)/OnlyFrom: \1/p" /etc/xinetd.d/* | head -n1
    elif inpath systemctl; then # systemd
        sed -n '/^IPAddressAllow/s/IPAddressAllow=/OnlyFrom: /p' "/usr/lib/systemd/system/check-mk-agent.socket" 2>/dev/null
        # NOTE: The above line just reads back the socket file we deployed ourselves. Systemd units can be altered by
        # other user defined unit files, so this *may* not be correct. A better way of doing this seemed to be querying
        # systemctl itself about the 'effective' property:
        #
        #    systemctl show --property IPAddressAllow "check-mk-agent.socket" | sed 's/IPAddressAllow=/OnlyFrom: /'
        #
        # However this ("successfully") reports an empty list or '[unprintable]' on older systemd versions :-(
    fi

    #
    # OS based labels are created from these variables
    #

    echo "OSType: linux"
    while read -r line; do
        raw_line="${line//\"/}"
        case $line in
            ID=*) echo "OSPlatform: ${raw_line##*=}" ;;
            NAME=*) echo "OSName: ${raw_line##*=}" ;;
            VERSION_ID=*) echo "OSVersion: ${raw_line##*=}" ;;
        esac
    done <<<"$(cat /etc/os-release 2>/dev/null)"

    #
    # BEGIN COMMON AGENT CODE
    #

    if [ -n "${NO_PYTHON}" ]; then
        python_fail_msg="No suitable python installation found."
    elif [ -n "${WRONG_PYTHON_COMMAND}" ]; then
        python_fail_msg="Configured python command not found."
    fi

    cat <<HERE
FailedPythonReason: ${python_fail_msg}
SSHClient: ${SSH_CLIENT}
HERE
}

section_cmk_agent_ctl_status() {
    cmk-agent-ctl --version 2>/dev/null >&2 || return

    printf "<<<cmk_agent_ctl_status:sep(0)>>>\n"
    cmk-agent-ctl status --json --no-query-remote
}

section_checkmk_agent_plugins() {
    printf "<<<checkmk_agent_plugins_lnx:sep(0)>>>\n"
    printf "pluginsdir %s\n" "${PLUGINSDIR}"
    printf "localdir %s\n" "${LOCALDIR}"
    for script in \
        "${PLUGINSDIR}"/* \
        "${PLUGINSDIR}"/[1-9]*/* \
        "${LOCALDIR}"/* \
        "${LOCALDIR}"/[1-9]*/*; do
        if is_valid_plugin "${script}"; then
            script_version=$(grep -e '^__version__' -e '^CMK_VERSION' "${script}" || echo 'CMK_VERSION="unversioned"')
            printf "%s:%s\n" "${script}" "${script_version}"
        fi
    done
}

section_checkmk_failed_plugin() {
    ${MK_RUN_SYNC_PARTS} || return
    echo "<<<check_mk>>>"
    echo "FailedPythonPlugins: ${1}"
}

#
# END COMMON AGENT CODE
#

#
# CHECK SECTIONS
#

section_labels() {
    echo '<<<labels:sep(0)>>>'

    if [ -n "${IS_DOCKERIZED}" ] || [ -n "${IS_LXC_CONTAINER}" ]; then
        echo '{"cmk/device_type":"container"}'
    elif grep "hypervisor" /proc/cpuinfo >/dev/null 2>&1; then
        echo '{"cmk/device_type":"vm"}'
    fi
}

section_mem() {
    if [ -n "${IS_DOCKERIZED}" ]; then
        echo "<<<docker_container_mem${CGROUP_SECTION_SUFFIX}>>>"
        if [ -n "${IS_CGROUP_V2}" ]; then
            cat /sys/fs/cgroup/memory.stat
            echo "memory.current $(cat /sys/fs/cgroup/memory.current)"
            echo "memory.max $(cat /sys/fs/cgroup/memory.max)"
        else
            cat /sys/fs/cgroup/memory/memory.stat
            echo "usage_in_bytes $(cat /sys/fs/cgroup/memory/memory.usage_in_bytes)"
            echo "limit_in_bytes $(cat /sys/fs/cgroup/memory/memory.limit_in_bytes)"
        fi
        grep -F 'MemTotal:' /proc/meminfo
    elif [ -n "${IS_LXC_CONTAINER}" ]; then
        echo '<<<mem>>>'
        grep -v -E '^Swap:|^Mem:|total:|^Vmalloc|^Committed' </proc/meminfo
    else
        echo '<<<mem>>>'
        grep -v -E '^Swap:|^Mem:|total:' </proc/meminfo
    fi
}

section_cpu() {
    case "$(uname -m)" in
        "armv7l" | "armv6l" | "aarch64")
            CPU_REGEX='^processor'
            ;;
        *)
            CPU_REGEX='^CPU|^processor'
            ;;
    esac
    NUM_CPUS=$(grep -c -E ${CPU_REGEX} </proc/cpuinfo)

    if [ -z "${IS_DOCKERIZED}" ] && [ -z "${IS_LXC_CONTAINER}" ]; then
        echo '<<<cpu>>>'
        echo "$(cat /proc/loadavg) ${NUM_CPUS}"
        if [ -f "/proc/sys/kernel/threads-max" ]; then
            cat /proc/sys/kernel/threads-max
        fi
    else
        if [ -n "${IS_DOCKERIZED}" ]; then
            echo "<<<docker_container_cpu${CGROUP_SECTION_SUFFIX}>>>"
        else
            echo "<<<lxc_container_cpu${CGROUP_SECTION_SUFFIX}>>>"
        fi
        if [ -n "${IS_CGROUP_V2}" ]; then
            echo "uptime $(cat /proc/uptime)"
            echo "num_cpus ${NUM_CPUS}"
            cat /sys/fs/cgroup/cpu.stat
        else
            grep "^cpu " /proc/stat
            echo "num_cpus ${NUM_CPUS}"
            cat /sys/fs/cgroup/cpuacct/cpuacct.stat
        fi
    fi
}

section_uptime() {
    echo '<<<uptime>>>'
    if [ -z "${IS_DOCKERIZED}" ]; then
        cat /proc/uptime
    else
        echo "$(($(get_epoch) - $(stat -c %Z /dev/pts)))"
    fi
}

# Print out Partitions / Filesystems. (-P gives non-wrapped POSIXed output)
# Heads up: NFS-mounts are generally supressed to avoid agent hangs.
# If hard NFS mounts are configured or you have too large nfs retry/timeout
# settings, accessing those mounts from the agent would leave you with
# thousands of agent processes and, ultimately, a dead monitored system.
# These should generally be monitored on the NFS server, not on the clients.
section_df() {
    if [ -n "${IS_DOCKERIZED}" ]; then
        return
    fi

    # The exclusion list is getting a bit of a problem.
    # -l should hide any remote FS but seems to be all but working.
    excludefs="-x smbfs -x cifs -x iso9660 -x udf -x nfsv4 -x nfs -x mvfs -x prl_fs -x squashfs -x devtmpfs -x autofs -x beegfs"
    if [ -z "${IS_LXC_CONTAINER}" ]; then
        excludefs="${excludefs} -x zfs"
    fi

    echo '<<<df_v2>>>'
    # We really *need* word splitting below!
    # shellcheck disable=SC2086
    df -PTlk ${excludefs} | sed 1d

    # df inodes information
    echo '<<<df_v2>>>'
    echo '[df_inodes_start]'
    # We really *need* word splitting below!
    # shellcheck disable=SC2086
    df -PTli ${excludefs} | sed 1d
    echo '[df_inodes_end]'

    if inpath lsblk; then
        echo "[df_lsblk_start]"
        lsblk --list --paths --output NAME,UUID
        echo "[df_lsblk_end]"
    fi
}

section_systemd() {
    if inpath systemctl; then
        echo '<<<systemd_units>>>'
        # use plain to force ASCII output that is simpler to parse
        echo "[list-unit-files]"
        systemctl list-unit-files --full --no-legend --no-pager --plain --type service --type socket | tr -s ' '
        echo "[status]"
        systemctl status --all --type service --type socket --no-pager --lines 0 | tr -s ' '
        echo "[all]"
        systemctl --all --type service --type socket --full --no-legend --no-pager --plain | sed '/^$/q' | tr -s ' '
    fi
}

section_zfs() {
    if inpath zfs; then
        echo '<<<zfsget:sep(9)>>>'
        zfs get -t filesystem,volume -Hp name,quota,used,avail,mountpoint,type 2>/dev/null
        echo '<<<zfsget>>>'
        echo '[df]'
        df -PTlk -t zfs | sed 1d
    fi
}

section_nfs_mounts() {
    proc_mounts_file=${1}

    if inpath waitmax; then
        STAT_VERSION=$(stat --version | head -1 | cut -d" " -f4)
        STAT_BROKE="5.3.0"

        json_templ() {
            echo '{"mountpoint": "'"${1}"'", "source": "'"${2}"'", "state": "ok", "usage": {"total_blocks": %b, "free_blocks_su": %f, "free_blocks": %a, "blocksize": %s}}'
        }
        json_templ_empty() {
            echo '{"mountpoint": "'"${1}"'", "source": "'"${2}"'", "state": "hanging", "usage": {"total_blocks": 0, "free_blocks_su": 0, "free_blocks": 0, "blocksize": 0}}'
        }

        echo '<<<nfsmounts_v2:sep(0)>>>'

        sed -n '/ nfs4\? /s/\([^ ]*\) \([^ ]*\) .*/\1 \2/p' <"${proc_mounts_file}" |
            while read -r MD MP; do
                MD="$(printf "%s" "${MD}" | sed 's/\\040/ /g')"
                MP="$(printf "%s" "${MP}" | sed 's/\\040/ /g')"
                if [ "${STAT_VERSION}" != "${STAT_BROKE}" ]; then
                    waitmax -s 9 5 stat -f -c "$(json_templ "${MP}" "${MD}")" "${MP}" ||
                        json_templ_empty "${MP}" "${MD}"
                else
                    (waitmax -s 9 5 stat -f -c "$(json_templ "${MP}" "${MD}")" "${MP}" &&
                        printf '\n') || json_templ_empty "${MP}" "${MD}"
                fi
            done

        echo '<<<cifsmounts>>>'
        sed -n -e '/ cifs /s/.*\ \([^ ]*\)\ cifs\ .*/\1/p' <"${proc_mounts_file}" |
            while read -r MP; do
                MP="$(printf "%s" "${MP}" | sed 's/\\040/ /g')"
                if [ ! -r "${MP}" ]; then
                    echo "${MP} Permission denied"
                elif [ "${STAT_VERSION}" != "${STAT_BROKE}" ]; then
                    waitmax -s 9 2 stat -f -c "${MP} ok %b %f %a %s" "${MP}" ||
                        echo "${MP} hanging 0 0 0 0"
                else
                    waitmax -s 9 2 stat -f -c "${MP} ok %b %f %a %s" "${MP}" &&
                        printf '\n' || echo "${MP} hanging 0 0 0 0"
                fi
            done
    fi
}

section_mounts() {
    echo '<<<mounts>>>'
    grep ^/dev </proc/mounts | grep -v " squashfs "
}

section_ps() {
    if inpath ps; then
        # processes including username, without kernel processes
        echo '<<<ps_lnx>>>'
        echo "[time]"
        get_epoch
        echo "[processes]"
        CGROUP=""
        if [ -e /sys/fs/cgroup ]; then
            CGROUP="cgroup:512,"
        fi
        echo "[header] $(ps ax -ww -o "${CGROUP}"user:32,vsz,rss,cputime,etime,pid,command | tr -s ' ')"
    fi
}

section_lnx_if() {
    if inpath ip; then
        echo '<<<lnx_if>>>'
        echo "[start_iplink]"
        ip address
        echo "[end_iplink]"
    fi

    echo '<<<lnx_if:sep(58)>>>'
    sed 1,2d /proc/net/dev
    sed -e 1,2d /proc/net/dev | cut -d':' -f1 | sort | while read -r eth; do
        echo "[${eth}]"
        if inpath ethtool; then
            ethtool "${eth}" | grep -E '(Speed|Duplex|Link detected|Auto-negotiation):'
        else
            # If interface down we get "Invalid argument"
            speed=$(cat "/sys/class/net/${eth}/speed" 2>/dev/null)
            if [ -n "${speed}" ] && [ "${speed}" -ge 0 ]; then
                echo "Speed: ${speed}Mb/s"
            fi
        fi
        echo "Address: $(cat "/sys/class/net/${eth}/address")"
    done
}

section_bonding_interfaces() {
    (
        cd /proc/net/bonding 2>/dev/null || return
        echo '<<<lnx_bonding:sep(58)>>>'
        head -v -n 1000 ./*
    )
}

section_vswitch_bonding() {
    if inpath ovs-appctl; then
        BONDS=$(ovs-appctl bond/list)
        COL=$(echo "${BONDS}" | awk '{for(i=1;i<=NF;i++) {if($i == "bond") printf("%d", i)} exit 0}')
        echo '<<<ovs_bonding:sep(58)>>>'
        for bond in $(echo "${BONDS}" | sed -e 1d | cut -f"${COL}"); do
            echo "[${bond}]"
            ovs-appctl bond/show "${bond}"
        done
    fi
}

section_tcp() {
    if inpath waitmax; then
        echo '<<<tcp_conn_stats>>>'
        if OUTPUT=$(waitmax 5 cat /proc/net/tcp /proc/net/tcp6 2>/dev/null | awk ' /:/ { c[$4]++; } END { for (x in c) { print x, c[x]; } }'); then
            echo "${OUTPUT}"
        elif inpath ss; then
            ss -ant | grep -v ^State | awk ' /:/ { c[$1]++; } END { for (x in c) { print x, c[x]; } }' |
                sed -e 's/^ESTAB/01/g;s/^SYN-SENT/02/g;s/^SYN-RECV/03/g;s/^FIN-WAIT-1/04/g;s/^FIN-WAIT-2/05/g;s/^TIME-WAIT/06/g;s/^CLOSED/07/g;s/^CLOSE-WAIT/08/g;s/^LAST-ACK/09/g;s/^LISTEN/0A/g;s/^CLOSING/0B/g;'
        fi
    fi
}

section_multipathing() {
    if inpath multipath; then
        echo '<<<multipath>>>'
        multipath -l
    fi
}

section_diskstat() {
    if [ -z "${IS_DOCKERIZED}" ]; then
        echo '<<<diskstat>>>'
        get_epoch
        grep -E ' (x?[shv]d[a-z]*[0-9]*|cciss/c[0-9]+d[0-9]+|emcpower[a-z]+|dm-[0-9]+|VxVM.*|mmcblk.*|dasd[a-z]*|bcache[0-9]+|nvme[0-9]+n[0-9]+) ' </proc/diskstats
        if inpath dmsetup; then
            echo '[dmsetup_info]'
            dmsetup info -c --noheadings --separator ' ' -o name,devno,vg_name,lv_name
        fi
        if [ -d /dev/vx/dsk ]; then
            echo '[vx_dsk]'
            stat -c "%t %T %n" /dev/vx/dsk/*/*
        fi
    else
        echo "<<<docker_container_diskstat${CGROUP_SECTION_SUFFIX}>>>"
        echo "[time]"
        get_epoch
        if [ -n "${IS_CGROUP_V2}" ]; then
            echo "[io.stat]"
            cat "/sys/fs/cgroup/io.stat"
        else
            for F in io_service_bytes io_serviced; do
                echo "[${F}]"
                cat "/sys/fs/cgroup/blkio/blkio.throttle.${F}"
            done
        fi
        echo "[names]"
        for F in /sys/block/*; do
            echo "${F##*/} $(cat "${F}/dev")"
        done
    fi
}

section_chrony() {
    if inpath chronyc; then
        # Force successful exit code. Otherwise section will be missing if daemon not running
        #
        # The "| cat" has been added for some kind of regression in RedHat 7.5. The
        # SELinux rules shipped with that release were denying the chronyc call
        # without cat.
        _run_cached_internal "chrony" 30 120 200 20 "echo '<<<chrony>>>'; waitmax 5 chronyc -n tracking | cat || true"
    fi
}

section_kernel() {
    if [ -z "${IS_DOCKERIZED}" ] && [ -z "${IS_LXC_CONTAINER}" ]; then
        echo '<<<kernel>>>'
        get_epoch
        cat /proc/vmstat /proc/stat
    fi
}

section_ipmitool() {
    if inpath ipmitool; then
        _run_cached_internal "ipmi" 300 300 900 600 "echo '<<<ipmi:sep(124)>>>'; waitmax 300 ipmitool sensor list | grep -v 'command failed' | grep -v -E '^[^ ]+ na ' | grep -v ' discrete '"
        # readable discrete sensor states
        _run_cached_internal "ipmi_discrete" 300 300 900 600 "echo '<<<ipmi_discrete:sep(124)>>>'; waitmax 300 ipmitool sdr elist compact"
    fi
}

section_ipmisensors() {
    inpath ipmi-sensors && ls /dev/ipmi* >/dev/null || return

    if ipmi-sensors --help | grep -q " \-\-groups"; then
        IPMI_GROUP_OPT="-g"
    else
        IPMI_GROUP_OPT="-t"
    fi

    # At least with ipmi-sensors 0.7.16 this group is Power_Unit instead of "Power Unit"
    _run_cached_internal "ipmi_sensors" 300 300 900 600 "echo '<<<ipmi_sensors:sep(124)>>>'; for class in Temperature Power_Unit Fan; do
        ipmi-sensors --sdr-cache-directory /var/cache ${IPMI_GROUP_OPT} \"\${class}\"
        # In case of a timeout immediately leave loop.
        if [ $? = 255 ]; then break; fi
    done"
}

section_md() {
    echo '<<<md>>>'
    cat /proc/mdstat
}

section_dm_raid() {
    if inpath dmraid && DMSTATUS=$(waitmax 3 dmraid -r); then
        echo '<<<dmraid>>>'

        # Output name and status
        waitmax 20 dmraid -s | grep -e ^name -e ^status

        # Output disk names of the RAID disks
        DISKS=$(echo "${DMSTATUS}" | cut -f1 -d":")

        for disk in ${DISKS}; do
            device=$(cat /sys/block/"$(basename "${disk}")"/device/model)
            status=$(echo "${DMSTATUS}" | grep "^${disk}")
            echo "${status} Model: ${device}"
        done
    fi
}

section_cfggen() {
    if inpath cfggen; then
        echo '<<<lsi>>>'
        cfggen 0 DISPLAY |
            grep -E '(Target ID|State|Volume ID|Status of volume)[[:space:]]*:' |
            sed -e 's/ *//g' -e 's/:/ /'
    fi
}

section_storcli() {
    if inpath storcli; then
        _storcli() { storcli "$@"; }
    elif inpath storcli64; then
        _storcli() { storcli64 "$@"; }
    else
        return 1
    fi

    echo '<<<storcli_physical_disks>>>'
    _storcli /call/eall/sall show all

    echo '<<<storcli_virtual_disks>>>'
    _storcli /call/vall show all

    echo '<<<storcli_cache_vault:sep(0)>>>'
    _storcli /call/cv show all

    # exit successfully, because storcli was in the path.
    return 0
}

section_megaraid() {
    section_storcli && return

    if inpath MegaCli; then
        MegaCli_bin="MegaCli"
    elif inpath MegaCli64; then
        MegaCli_bin="MegaCli64"
    elif inpath megacli; then
        MegaCli_bin="megacli"
    else
        return 1
    fi

    echo '<<<megaraid_pdisks>>>'
    for part in $(${MegaCli_bin} -EncInfo -aALL -NoLog </dev/null |
        sed -rn 's/:/ /g; s/[[:space:]]+/ /g; s/^ //; s/ $//; s/Number of enclosures on adapter ([0-9]+).*/adapter \1/g; /^(Enclosure|Device ID|adapter) [0-9]+$/ p'); do
        [ "${part}" = adapter ] && printf "\n"
        [ "${part}" = 'Enclosure' ] && printf "\ndev2enc"
        printf " %s" "${part}"
    done
    echo
    ${MegaCli_bin} -PDList -aALL -NoLog </dev/null |
        grep -E 'Enclosure|Raw Size|Slot Number|Device Id|Firmware state|Inquiry|Adapter|Predictive Failure Count'
    echo '<<<megaraid_ldisks>>>'
    ${MegaCli_bin} -LDInfo -Lall -aALL -NoLog </dev/null | grep -E 'Size|State|Number|Adapter|Virtual'
    echo '<<<megaraid_bbu>>>'
    ${MegaCli_bin} -AdpBbuCmd -GetBbuStatus -aALL -NoLog </dev/null | grep -v Exit
}

section_3ware_raid() {
    if inpath tw_cli; then
        for C in $(tw_cli show | awk 'NR < 4 { next } { print $1 }'); do
            echo '<<<3ware_info>>>'
            tw_cli "/${C}" show all | grep -E 'Model =|Firmware|Serial'
            echo '<<<3ware_disks>>>'
            tw_cli "/${C}" show drivestatus | grep -E 'p[0-9]' | sed "s/^/${C}\//"
            echo '<<<3ware_units>>>'
            tw_cli "/${C}" show unitstatus | grep -E 'u[0-9]' | sed "s/^/${C}\//"
        done
    fi
}

section_areca_raid() {
    if inpath cli64; then
        _run_cached_internal "arc_raid_status" 300 300 900 600 "echo '<<<arc_raid_status>>>'; cli64 rsf info | tail -n +3 | head -n -2"
    fi
}

section_vbox_guest() {
    echo '<<<vbox_guest>>>'
    if inpath VBoxControl && lsmod | grep vboxguest >/dev/null 2>&1; then
        (VBoxControl -nologo guestproperty enumerate || echo "ERROR") | cut -d, -f1,2
    fi
}

section_openvpn() {
    if [ -e /etc/openvpn/openvpn-status.log ]; then
        echo '<<<openvpn_clients:sep(44)>>>'
        sed -n -e '/CLIENT LIST/,/ROUTING TABLE/p' </etc/openvpn/openvpn-status.log |
            sed -e 1,3d -e '$d'
    fi
}

section_nvidia() {
    if inpath nvidia-settings && [ -S /tmp/.X11-unix/X0 ]; then
        echo '<<<nvidia>>>'
        for var in GPUErrors GPUCoreTemp; do
            DISPLAY=:0 waitmax 2 nvidia-settings -t -q ${var} | sed "s/^/${var}: /"
        done
    fi
}

section_drbd() {
    if [ -z "${IS_DOCKERIZED}" ] && [ -z "${IS_LXC_CONTAINER}" ] && [ -e /proc/drbd ]; then
        echo '<<<drbd>>>'
        cat /proc/drbd
        cat /sys/kernel/debug/drbd/resources/*/connections/*/0/proc_drbd 2>/dev/null
    fi
}

section_heartbeat() {
    if [ -S /var/run/heartbeat/crm/cib_ro ] || [ -S /var/run/crm/cib_ro ] || pgrep "^(crmd|pacemaker-contr)$" >/dev/null 2>&1; then
        echo '<<<heartbeat_crm>>>'
        TZ=UTC crm_mon -1 -r | grep -v ^$ | sed 's/^ //; /^\sResource Group:/,$ s/^\s//; s/^\s/_/g'
    fi

    if inpath cl_status; then
        echo '<<<heartbeat_rscstatus>>>'
        cl_status rscstatus

        echo '<<<heartbeat_nodes>>>'
        for NODE in $(cl_status listnodes); do
            if [ "${NODE}" != "$(uname -n | tr '[:upper:]' '[:lower:]')" ]; then
                STATUS=$(cl_status nodestatus "${NODE}")
                printf "%s %s" "${NODE}" "${STATUS}"
                for LINK in $(cl_status listhblinks "${NODE}" 2>/dev/null); do
                    printf " %s %s" "${LINK}" "$(cl_status hblinkstatus "${NODE}" "${LINK}")"
                done
                echo
            fi
        done
    fi
}

## Postfix mailqueue monitoring
## Determine the number of mails and their size in several postfix mail queues
read_postfix_queue_dirs() {
    postfix_queue_dir=${1}
    if [ -n "${postfix_queue_dir}" ]; then
        echo '<<<postfix_mailq>>>'
        echo "[[[${2}]]]"
        for queue in deferred active; do
            count=$(find "${postfix_queue_dir}/${queue}" -type f | wc -l)
            size=$(du -s "${postfix_queue_dir}/${queue}" | awk '{print $1 }')
            if [ -z "${size}" ]; then
                size=0
            fi
            if [ -z "${count}" ]; then
                echo "Mail queue is empty"
            else
                echo "QUEUE_${queue} ${size} ${count}"
            fi
        done
    fi
}

## Postfix status monitoring
read_postfix_master_pid() {
    postfix_queue_dir=${1}
    postfix_instance_name=${2}
    echo "<<<postfix_mailq_status:sep(58)>>>"
    if [ -e "${postfix_queue_dir}/pid/master.pid" ]; then
        if [ -r "${postfix_queue_dir}/pid/master.pid" ]; then
            postfix_pid=$(sed 's/ //g' <"${postfix_queue_dir}/pid/master.pid") # handle possible spaces in output
            if ps -p "${postfix_pid}" -o cmd= | grep -q ".*postfix/\(s\?bin/\)\?/\?master.*"; then
                echo "${postfix_instance_name}:the Postfix mail system is running:PID:${postfix_pid}"
            else
                echo "${postfix_instance_name}:PID file exists but instance is not running!"
            fi
        else
            echo "${postfix_instance_name}:PID file exists but is not readable"
        fi
    else
        echo "${postfix_instance_name}:the Postfix mail system is not running"
    fi
}

## Postfix mailqueue monitoring
## Determine the number of mails and their size in several postfix mail queue
section_mailqueue() {
    if inpath postconf; then
        # Check if multi_instance_directories exists in main.cf and is not empty
        # always takes the last entry, multiple entries possible
        multi_instances_dirs=$(postconf -c /etc/postfix 2>/dev/null | grep ^multi_instance_directories | sed 's/.*=[[:space:]]*//g')
        if [ -n "${multi_instances_dirs}" ]; then
            for queue_dir in ${multi_instances_dirs}; do
                if [ -n "${queue_dir}" ]; then
                    postfix_queue_dir=$(postconf -c "${queue_dir}" 2>/dev/null | grep ^queue_directory | sed 's/.*=[[:space:]]*//g')
                    read_postfix_queue_dirs "${postfix_queue_dir}" "${queue_dir}"
                    postfix_instance_name=$(postconf -c "${queue_dir}" -h multi_instance_name 2>/dev/null)
                    read_postfix_master_pid "${postfix_queue_dir}" "${postfix_instance_name}"
                fi
            done
        fi
        # Always check for the default queue. It can exist even if multiple instances are configured
        read_postfix_queue_dirs "$(postconf -h queue_directory 2>/dev/null)" "default"
        read_postfix_master_pid "$(postconf -h queue_directory 2>/dev/null)" "default"

    elif [ -x /usr/sbin/ssmtp ]; then
        echo '<<<postfix_mailq>>>'
        mailq 2>&1 | sed 's/^[^:]*: \(.*\)/\1/' | tail -n 6
    fi

    # Check status of qmail mailqueue
    if inpath qmail-qstat; then
        echo "<<<qmail_stats>>>"
        qmail-qstat
    fi

    # Nullmailer queue monitoring
    if inpath nullmailer-send; then
        echo '<<<nullmailer_mailq>>>'
        if [ -d /var/spool/nullmailer/queue ]; then
            COUNT=$(find /var/spool/nullmailer/queue -type f | wc -l)
            SIZE=$(du -s /var/spool/nullmailer/queue | awk '{print $1 }')
            echo "${SIZE} ${COUNT} deferred"
        fi
        if [ -d /var/spool/nullmailer/failed ]; then
            COUNT=$(find /var/spool/nullmailer/failed -type f | wc -l)
            SIZE=$(du -s /var/spool/nullmailer/failed | awk '{print $1 }')
            echo "${SIZE} ${COUNT} failed"
        fi
    fi
}

section_omd() {
    if inpath omd; then
        # 60 is _probably_ the agents polling interval. Why would you use that??
        _run_cached_internal "omd_status" 60 60 180 120 "echo '<<<omd_status>>>'; omd status --bare || true"

        ${MK_RUN_SYNC_PARTS} || return

        echo '<<<mknotifyd:sep(0)>>>'
        get_epoch
        for statefile in /omd/sites/*/var/log/mknotifyd.state; do
            if [ -e "${statefile}" ]; then
                site=${statefile%/var/log*}
                site=${site#/omd/sites/}
                echo "[${site}]"
                grep -v '^#' <"${statefile}"
            fi
        done

        echo '<<<omd_apache:sep(124)>>>'
        for statsfile in /omd/sites/*/var/log/apache/stats; do
            if [ -e "${statsfile}" ]; then
                site=${statsfile%/var/log*}
                site=${site#/omd/sites/}
                echo "[${site}]"
                cat "${statsfile}"
                : >"${statsfile}"
                # prevent next section to fail caused by a missing newline at the end of the statsfile
                echo
            fi
        done

        _du_no_errors() {
            if [ -e "${1}" ]; then
                output=$(du -bs "$1") && printf "%s\n" "${output}"
            else
                printf "0 %s\n" "${1}"
            fi
        }

        echo '<<<omd_diskusage:sep(0)>>>'
        for sitedir in /omd/sites/*; do
            site=${sitedir#/omd/sites/}
            echo "[site ${site}]"
            _du_no_errors "$sitedir"
            _du_no_errors "$sitedir/var/log"
            _du_no_errors "$sitedir/var/check_mk/rrd"
            _du_no_errors "$sitedir/var/pnp4nagios/"
            _du_no_errors "$sitedir/tmp/"
            _du_no_errors "$sitedir/local/"
            _du_no_errors "$sitedir/var/check_mk/agents/"
            _du_no_errors "$sitedir/var/mkeventd/history/"
            _du_no_errors "$sitedir/var/check_mk/core/"
            _du_no_errors "$sitedir/var/check_mk/inventory_archive/"
        done

        echo '<<<omd_info:sep(59)>>>'
        echo '[versions]'
        echo 'version;number;edition;demo'
        for versiondir in /omd/versions/*; do
            version=${versiondir#/omd/versions/}

            # filter out special directory 'default'
            if [ "${version}" = "default" ]; then
                continue
            fi

            number=${version}
            demo="0"
            if [ "${version##*.}" = "demo" ]; then
                number=${version%.demo}
                demo="1"
            fi
            edition=${number##*.}
            number=${number%.*}
            echo "${version};${number};${edition};${demo}"
        done
        echo '[sites]'
        echo 'site;used_version;autostart'
        for sitedir in /omd/sites/*; do
            site=${sitedir#/omd/sites/}
            used_version=$(readlink "${sitedir}"/version)
            used_version=${used_version##*/}
            autostart="0"
            if grep -q "CONFIG_AUTOSTART[[:blank:]]*=[[:blank:]]*'on'" "${sitedir}"/etc/omd/site.conf; then
                autostart="1"
            fi
            echo "${site};${used_version};${autostart}"
        done
    fi
}

section_zpool() {
    if inpath zpool; then
        echo "<<<zpool_status>>>"
        zpool status -x
        echo "<<<zpool>>>"
        zpool list
    fi
}

section_veritas_cluster() {
    if [ -x /opt/VRTSvcs/bin/haclus ]; then
        echo "<<<veritas_vcs>>>"
        vcshost=$(hostname | cut -d. -f1)
        waitmax -s 9 2 /opt/VRTSvcs/bin/haclus -display -localclus | grep -e ClusterName -e ClusState
        waitmax -s 9 2 /opt/VRTSvcs/bin/hasys -display -attribute SysState
        waitmax -s 9 2 /opt/VRTSvcs/bin/hagrp -display -sys "${vcshost}" -attribute State -localclus
        waitmax -s 9 2 /opt/VRTSvcs/bin/hares -display -sys "${vcshost}" -attribute State -localclus
        waitmax -s 9 2 /opt/VRTSvcs/bin/hagrp -display -attribute TFrozen -attribute Frozen
    fi
}

section_omd_core() {
    (
        cd /omd/sites || return

        # The files within a site are site-user writable! Therefore we must not use them!
        # The version files are only root writable so we can use them instead.
        site_version() {
            printf "%s" "$(realpath "${1}/version" | sed 's|.*/||')"
        }

        site_cmd() {
            # DO NOT ACCESS /omd/sites/${site}/bin/cmd directly.
            # bin might point anywhere -> priv escalation.
            printf "/omd/versions/%s/bin/%s" "$(site_version "${1}")" "${2}"
        }

        site_lib() {
            printf "/omd/versions/%s/lib" "$(site_version "${1}")"
        }

        waitmax_for_unixcat_with_site_ld_library_path() {
            LD_LIBRARY_PATH="$(site_lib "${2}"):${LD_LIBRARY_PATH}" waitmax "${1}" "$(site_cmd "${2}" unixcat)" "/omd/sites/${2}/tmp/run/${3}"
        }

        echo '<<<livestatus_status:sep(59)>>>'
        for site in *; do
            if [ -S "/omd/sites/${site}/tmp/run/live" ]; then
                echo "[${site}]"
                echo "GET status" |
                    waitmax_for_unixcat_with_site_ld_library_path 3 "${site}" "live"
            fi
        done

        echo '<<<livestatus_ssl_certs:sep(124)>>>'
        for site in *; do
            echo "[${site}]"
            for PEM_PATH in "/omd/sites/${site}/etc/ssl/ca.pem" "/omd/sites/${site}/etc/ssl/sites/${site}.pem"; do
                if [ -f "${PEM_PATH}" ]; then
                    CERT_DATE=$(openssl x509 -enddate -noout -in "${PEM_PATH}" | sed 's/notAfter=//')
                    echo "${PEM_PATH}|$(date --date="${CERT_DATE}" --utc +%s)"
                fi
            done
        done

        echo '<<<mkeventd_status:sep(0)>>>'
        for site in *; do
            if [ -S "/omd/sites/${site}/tmp/run/mkeventd/status" ]; then
                echo "[\"${site}\"]"
                (echo "GET status" && echo "OutputFormat: json") |
                    waitmax_for_unixcat_with_site_ld_library_path 3 "${site}" "mkeventd/status"
            fi
        done

        echo '<<<cmk_site_statistics:sep(59)>>>'
        for site in *; do
            if [ -S "/omd/sites/${site}/tmp/run/live" ]; then
                echo "[${site}]"
                waitmax_for_unixcat_with_site_ld_library_path 5 "${site}" "live" <<LimitString
GET hosts
Stats: state = 0
Stats: scheduled_downtime_depth = 0
StatsAnd: 2
Stats: state = 1
Stats: scheduled_downtime_depth = 0
StatsAnd: 2
Stats: state = 2
Stats: scheduled_downtime_depth = 0
StatsAnd: 2
Stats: scheduled_downtime_depth > 0
Filter: custom_variable_names < _REALNAME
LimitString
                waitmax_for_unixcat_with_site_ld_library_path 5 "${site}" "live" <<LimitString
GET services
Stats: state = 0
Stats: scheduled_downtime_depth = 0
Stats: host_scheduled_downtime_depth = 0
Stats: host_state = 0
Stats: host_has_been_checked = 1
StatsAnd: 5
Stats: scheduled_downtime_depth > 0
Stats: host_scheduled_downtime_depth > 0
StatsOr: 2
Stats: scheduled_downtime_depth = 0
Stats: host_scheduled_downtime_depth = 0
Stats: host_state != 0
StatsAnd: 3
Stats: state = 1
Stats: scheduled_downtime_depth = 0
Stats: host_scheduled_downtime_depth = 0
Stats: host_state = 0
Stats: host_has_been_checked = 1
StatsAnd: 5
Stats: state = 3
Stats: scheduled_downtime_depth = 0
Stats: host_scheduled_downtime_depth = 0
Stats: host_state = 0
Stats: host_has_been_checked = 1
StatsAnd: 5
Stats: state = 2
Stats: scheduled_downtime_depth = 0
Stats: host_scheduled_downtime_depth = 0
Stats: host_state = 0
Stats: host_has_been_checked = 1
StatsAnd: 5
Filter: host_custom_variable_names < _REALNAME
LimitString
            fi
        done
    )
}

section_mkbackup() {
    if ls /omd/sites/*/var/check_mk/backup/*.state >/dev/null 2>&1; then
        echo "<<<mkbackup>>>"
        for F in /omd/sites/*/var/check_mk/backup/*.state; do
            SITE=${F#/*/*/*}
            SITE=${SITE%%/*}

            JOB_IDENT=${F%.state}
            JOB_IDENT=${JOB_IDENT##*/}

            if [ "${JOB_IDENT}" != "restore" ]; then
                echo "[[[site:${SITE}:${JOB_IDENT}]]]"
                cat "${F}"
                echo
            fi
        done
    fi

    # Collect states of configured CMA backup jobs
    if inpath mkbackup && ls /var/lib/mkbackup/*.state >/dev/null 2>&1; then
        echo "<<<mkbackup>>>"
        for F in /var/lib/mkbackup/*.state; do
            JOB_IDENT=${F%.state}
            JOB_IDENT=${JOB_IDENT##*/}

            if [ "${JOB_IDENT}" != "restore" ]; then
                echo "[[[system:${JOB_IDENT}]]]"
                cat "${F}"
                echo
            fi
        done
    fi
}

section_thermal() {
    if [ -z "${IS_DOCKERIZED}" ] && [ -z "${IS_LXC_CONTAINER}" ] && ls /sys/class/thermal/thermal_zone* >/dev/null 2>&1; then
        echo '<<<lnx_thermal:sep(124)>>>'
        for F in /sys/class/thermal/thermal_zone*; do
            line="${F##*/}"
            if [ ! -e "${F}/mode" ]; then
                line="${line}|-"
            else
                line="${line}|$(cat "${F}"/mode)"
            fi

            line="${line}|$(cat "${F}/type")|$(cat "${F}/temp")"

            for G in "${F}"/trip_point_*_temp; do
                line="${line}|$(cat "$G")|$(cat "${G/%temp/type}")"
            done

            echo "$line"
        done
    fi
}

section_libelle() {
    if inpath trd; then
        echo "<<<libelle_business_shadow:sep(58)>>>"
        trd -s
    fi
}

section_http_accelerator() {
    if inpath varnishstat; then
        echo "<<<varnish>>>"
        varnishstat -1
    fi
}

section_proxmox() {
    if inpath pvecm; then
        echo "<<<pvecm_status:sep(58)>>>"
        pvecm status
        echo "<<<pvecm_nodes>>>"
        pvecm nodes
    fi
}

section_haproxy() {
    for HAPROXY_SOCK in /run/haproxy/admin.sock /var/lib/haproxy/stats; do
        if [ -r "${HAPROXY_SOCK}" ] && inpath socat; then
            echo "<<<haproxy:sep(44)>>>"
            echo "show stat" | socat - "UNIX-CONNECT:${HAPROXY_SOCK}"
        fi
    done
}

#
# BEGIN COMMON AGENT CODE
#

section_job() {
    # Get statistics about monitored jobs.

    _cat_files() {
        # read file names from stdin and write like `head -n -0 -v file`
        while read -r file; do
            printf "==> %s <==\n" "${file##./}"
            cat "${file}"
        done
    }

    (
        cd "${MK_VARDIR}/job" 2>/dev/null || return
        printf "<<<job>>>\n"
        for user in *; do
            (
                cd "${user}" 2>/dev/null || return # return from subshell only
                # This folder is owned (and thus writable) by the user that ran the jobs.
                # The agent (root) must not read files that are not owned by the user.
                # This prevents symlink or hardlink attacks.
                find -L . -type f -user "${user}" | _cat_files
            )
        done
    )
}

section_fileinfo() {
    # fileinfo check: put patterns for files into /etc/check_mk/fileinfo.cfg
    perl -e '
    use File::Glob "bsd_glob";
    my @patterns = ();
    foreach (bsd_glob("$ARGV[0]/fileinfo.cfg"), bsd_glob("$ARGV[0]/fileinfo.d/*")) {
        open my $handle, "<", $_ or next;
        while (<$handle>) {
            chomp;
            next if /^\s*(#|$)/;
            my $pattern = $_;
            $pattern =~ s/\$DATE:(.*?)\$/substr(`date +"$1"`, 0, -1)/eg;
            push @patterns, $pattern;
        }
        warn "error while reading $_: $!\n" if $!;
        close $handle;
    }
    exit if ! @patterns;

    my $file_stats = "";
    foreach (@patterns) {
        foreach (bsd_glob("$_")) {
            if (! -f) {
                $file_stats .= "$_|missing\n" if ! -d;
            } elsif (my @infos = stat) {
                $file_stats .= "$_|ok|$infos[7]|$infos[9]\n";
            } else {
                $file_stats .= "$_|stat failed: $!\n";
            }
        }
    }

    print "<<<fileinfo:sep(124)>>>\n", time, "\n[[[header]]]\nname|status|size|time\n[[[content]]]\n$file_stats";
    ' -- "${MK_CONFDIR}"
}

#
# END COMMON AGENT CODE
#

# ntpq helper function

get_ntpq() {
    inpath ntpq || return 1
    _run_cached_internal "ntp" 30 120 200 20 "echo '<<<ntp>>>'; waitmax 5 ntpq -np | sed -e 1,2d -e 's/^\(.\)/\1 /' -e 's/^ /%/' || true"
}

section_timesyncd() {
    if [ -n "${IS_DOCKERIZED}" ] || [ -n "${IS_LXC_CONTAINER}" ]; then
        return 0
    fi
    inpath systemctl || return 1
    inpath timedatectl || return 1
    systemctl is-enabled systemd-timesyncd.service >/dev/null 2>&1 || return 1
    # debian 10.8 uses ConditionFileIsExecutable to "disable" systemd-timedatectl when ntp is installed.
    # The service is still enabled, but does not start timesyncd as the condition is not met.
    (inpath ntpd || inpath openntpd || inpath chronyd || inpath VBoxService) && return 1 # we check the same condition as the systemd condition
    timedatectl timesync-status >/dev/null 2>&1 || return 1

    ${MK_RUN_SYNC_PARTS} || return 0

    echo "<<<timesyncd>>>"
    timedatectl timesync-status
    # /run/systemd/timesync/synchronized is a more reliable/the correct file to look at for > systemd v250
    if [ -f "/run/systemd/timesync/synchronized" ]; then
        get_file_mtime /run/systemd/timesync/synchronized | awk '{print "[[["$1"]]]"}'
    else
        get_file_mtime /var/lib/systemd/timesync/clock | awk '{print "[[["$1"]]]"}'
    fi

    echo "<<<timesyncd_ntpmessage:sep(10)>>>"
    timedatectl show-timesync | awk '/NTPMessage/{print $0}'
    timedatectl show | awk '/Timezone/{print $0}'
    return 0 # intended not to execute section_ntp even in the case where get_file_mtime fails
}

section_ntp() {
    if [ -n "${IS_DOCKERIZED}" ] || [ -n "${IS_LXC_CONTAINER}" ]; then
        return 0
    fi
    # First we try to identify if we're beholden to systemd
    if inpath systemctl; then
        # shellcheck disable=SC2016
        if [ "$(systemctl | awk '/ntp.service|ntpd.service|ntpsec.service/{print $3; exit}')" = "active" ]; then
            # remove heading, make first column space separated
            get_ntpq
            return
        fi
    fi

    # If we get to this point, we attempt via classic ntp daemons (ntpq required)
    if inpath ntpq; then
        # Try to determine status via /etc/init.d
        # This might also be appropriate for AIX, Solaris and others
        for _ntp_daemon in ntp ntpd openntpd; do
            # Check for a service script
            if [ -x /etc/init.d/"${_ntp_daemon}" ]; then
                # If the status returns 0, we assume we have a running service
                if /etc/init.d/"${_ntp_daemon}" status >/dev/null 2>&1; then
                    get_ntpq
                    return
                fi
            fi
        done
        unset -v _ntp_daemon

        # For other systems such as Slackware
        if [ -x "/etc/rc.d/rc.ntpd" ]; then
            get_ntpq
            return
        fi
    fi
}

run_real_time_checks() {
    RTC_PLUGINS=""
    # shellcheck source=agents/cfg_examples/real_time_checks.cfg
    . "${MK_CONFDIR}/real_time_checks.cfg" 2>/dev/null || return

    if [ -z "${RTC_SECRET}" ]; then
        define_optionally_encrypt "no"
    else
        inpath openssl || {
            echo "ERROR: openssl command is missing, but encryption is requested. Not sending real-time data." >&2
            return
        }
        define_optionally_encrypt "yes"
    fi

    for trigger in "${MK_VARDIR}/rtc_remotes/"?*; do
        # no such file => no expansion of ?* => nothing to do
        # braces are needed so run_real_time_checks_for_remote can be forked away
        # otherwise async execution of check plugins is held off by activated realtime checks.
        [ -e "${trigger}" ] && { run_real_time_checks_for_remote "${trigger}" "${RTC_SECRET}" >/dev/null & }
    done
}

_rt_pidfile_is_mine() {
    [ "$(cat "${1}" 2>/dev/null)" = "$$" ]
}

_rt_pidfile_is_alive() {
    [ "$(("$(get_epoch)" - "$(get_file_atime "${1}")"))" -le "${RTC_TIMEOUT}" ]
}

_rt_timestamp() {
    get_epoch | tr -d '\n'
}

_rt_sendudp() {
    # concatenate the output of all commands to a single udp packet
    dd bs=9999 iflag=fullblock 2>/dev/null >"/dev/udp/${1}/${2}"
}

# Implements Real-Time Check feature of the Checkmk agent which can send
# some section data in 1 second resolution. Useful for fast notifications and
# detailed graphing (if you configure your RRDs to this resolution).
#  2 bytes: protocol version
#  10 bytes: timestamp
#  rest: encrypted data
# Be aware of maximum packet size.
run_real_time_checks_for_remote() {
    pidfile="${1}"
    secret="${2}"
    remote="${pidfile##*/rtc_remotes/}"

    # have I already started for this remote?
    _rt_pidfile_is_mine "${pidfile}" && return

    echo $$ >"${pidfile}"

    while true; do
        _rt_pidfile_is_mine "${pidfile}" || return
        _rt_pidfile_is_alive "${pidfile}" || {
            rm "${pidfile}"
            return
        }

        for section in ${RTC_SECTIONS}; do
            section_"${section}" |
                optionally_encrypt "${secret}" "$(_rt_timestamp)" |
                _rt_sendudp "${remote}" "${RTC_PORT}"
        done

        # Plugins
        cd "${PLUGINSDIR}" || continue

        for script in ${RTC_PLUGINS}; do
            is_valid_plugin "${script}" || continue
            plugin_interpreter=$(get_plugin_interpreter "${script}") || continue

            "${plugin_interpreter}" "${script}" |
                optionally_encrypt "${secret}" "$(_rt_timestamp)" |
                _rt_sendudp "${remote}" "${RTC_PORT}"
        done

        sleep 1
    done
}

#
# BEGIN COMMON AGENT CODE
#

run_cached() {
    # Compatibility wrapper for plugins that might use run_cached.
    # We should have never exposed this as quasi API.
    NAME="${1}"
    MAXAGE="${2}"
    REFRESH_INTERVAL="${3}"
    shift 3

    OUTPUT_TIMEOUT=$((MAXAGE * 3))
    CREATION_TIMEOUT=$((MAXAGE * 2))

    _run_cached_internal "${NAME}" "${REFRESH_INTERVAL}" "${MAXAGE}" "${OUTPUT_TIMEOUT}" "${CREATION_TIMEOUT}" "$@"
}

if inpath setsid; then
    # we can kill the whole process group, including children.
    _nohup_kill_id() { printf "0"; }
    _nohup() { setsid nohup "$@"; }
else
    # we can only the main process, children will survive :-/
    _nohup_kill_id() { printf "\$\$"; }
    _nohup() { nohup "$@"; }
fi

_run_cached_internal() {
    # Run a command asynchronous by use of a cache file.
    # Usage: _run_cached_internal NAME REFRESH_INTERVAL MAXAGE OUTPUT_TIMEOUT OUTPUT_TIMEOUT CREATION_TIMEOUT [COMMAND ...]
    # Note that while multiple COMMAND arguments are considered, they are evaluated in a string.
    # This means that extra escaping is required.
    # For example:
    # To run a cat command every two minutes, considering the created data valid for one three minutes,
    # send the created data for four minutes and allowing the command to run for 12 minutes, you'll have to call
    #
    #   _run_cached_interal "my_file_content" 120 180 240 720 "cat \"My File\""
    #
    # Mind the escaping...

    NAME="${1}"
    # name of the section (also used as cache file name)

    REFRESH_INTERVAL="${2}"
    # threshold in seconds when the cache file needs to be regenerated

    MAXAGE="${3}"
    # maximum cache livetime in seconds

    OUTPUT_TIMEOUT="${4}"
    # threshold in seconds for how long the cache file will be output (regardless of whether it is outdated)

    CREATION_TIMEOUT="${5}"
    # threshold in seconds for how long the process is allowed to be running before it is killed (see below for details)

    shift 5
    # $* is now the command to run

    if ${DISABLE_CACHING:-false}; then
        # We need the re-splitting to be compatible with the caching case, so:
        # shellcheck disable=SC2068
        $@
        return
    fi

    [ -d "${MK_VARDIR}/cache" ] || mkdir -p "${MK_VARDIR}/cache"
    CACHEFILE="${MK_VARDIR}/cache/${NAME}.cache"
    FAIL_REPORT_FILE="${SPOOLDIR}/${NAME}.cachefail"

    NOW="$(get_epoch)"
    MTIME="$(get_file_mtime "${CACHEFILE}" 2>/dev/null)" || MTIME=0

    if ${MK_RUN_SYNC_PARTS}; then
        if [ -s "${CACHEFILE}" ] && [ $((NOW - MTIME)) -le "${OUTPUT_TIMEOUT}" ]; then
            # Output the file (if it is not too outdated)
            CACHE_INFO="cached(${MTIME},${MAXAGE})"
            # prefix or insert cache info, unless already present.
            # WATCH OUT: AIX does not allow us to pass this as a single '-e' option!
            if [ "${NAME%%_*}" = "local" ] || [ "${NAME%%_*}" = "mrpe" ]; then
                sed -e '/^<<<.*>>>/{p;d;}' -e '/^cached([0-9]*,[0-9]*) /{p;d;}' -e "s/^/${CACHE_INFO} /" "${CACHEFILE}"
            else
                sed -e '/^<<<.*\(:cached(\).*>>>/{p;d;}' -e 's/^<<<\([^>]*\)>>>$/<<<\1:'"${CACHE_INFO}"'>>>/' "${CACHEFILE}"
            fi
        fi

    fi

    if ${MK_RUN_ASYNC_PARTS}; then
        # This does the right thing, regardless whether the pattern matches!
        _cfile_in_use() {
            for cfile in "${CACHEFILE}.new."*; do
                printf "%s\n" "${cfile}"
                break
            done
        }

        # Time to refresh cache file and new job not yet running?
        if [ $((NOW - MTIME)) -gt "${REFRESH_INTERVAL}" ] && [ ! -e "$(_cfile_in_use)" ]; then

            # Start it.
            # We're running two parrallel blocks, implementing a timeout. Roughly:
            # First block: Run command then kill ourselves (including the other block!)
            # Second block: Sleep for a while. If I survive: Handle the fact that block one did not kill me.
            cat <<HERE | _nohup "${CURRENT_SHELL}" >/dev/null 2>&1 &
             {
                eval '${MK_DEFINE_LOG_SECTION_TIME}'
                exec > "${CACHEFILE}.new.\$\$" || exit 1
                $* \
                && mv -f "${CACHEFILE}.new.\$\$" "${CACHEFILE}" && rm -f "${FAIL_REPORT_FILE}" \
                || rm -f "${CACHEFILE}.new.\$\$"
                kill $(_nohup_kill_id)
             } &
             {
                sleep ${CREATION_TIMEOUT}
                {
                      printf "<<<checkmk_cached_plugins:sep(124)>>>\\n"
                      printf "timeout|${NAME}|${CREATION_TIMEOUT}|\$\$\\n"
                } >"${FAIL_REPORT_FILE}" 2>&1
                rm -f "${CACHEFILE}.new.\$\$"
                kill -9 $(_nohup_kill_id)
             } &
HERE
        fi

    fi

    unset NAME MAXAGE CREATION_TIMEOUT REFRESH_INTERVAL CACHEFILE NOW MTIME CACHE_INFO TRYING_SINCE OUTPUT_TIMEOUT
}

run_local_checks() {
    cd "${LOCALDIR}" || return

    if ${MK_RUN_SYNC_PARTS}; then
        echo '<<<local:sep(0)>>>'
        for script in ./*; do
            if is_valid_plugin "${script}"; then
                _log_section_time "${script}"
            fi
        done
    fi

    # Call some local checks only every X'th second
    for script in [1-9]*/*; do
        if is_valid_plugin "${script}"; then
            interval="${script%/*}"
            _run_cached_internal "local_${script##*/}" "${interval}" "${interval}" $((interval * 3)) $((interval * 2)) "_log_section_time '${script}'"
        fi
    done
}

run_spooler() {
    (
        cd "${SPOOLDIR}" 2>/dev/null || return

        now=$(get_epoch)

        for file in *; do
            [ "${file}" != "*" ] || return

            # If prefixed with a number, then that is the maximum age in seconds.
            # If the file is older than that, it is ignored.
            maxage="${file%%[^0-9]*}"
            if [ "${maxage}" ]; then
                mtime=$(get_file_mtime "${file}")
                [ $((now - mtime)) -le "${maxage}" ] || continue
            fi

            cat "${file}"
        done
    )
}

get_plugin_interpreter() {
    # Return the interpreter (or "") for the plugin file (or fail).
    # We return the interpreter instead of wrapping the call, so we don't
    # have to export the function (which is not portable).

    # normalize input
    agent_plugin="${1#./}"

    extension="${agent_plugin##*.}"
    filename="${agent_plugin%.*}"

    # Execute all non python plugins with ./foo
    if [ "${extension}" != "py" ]; then
        return 0
    fi

    if [ "${filename#"${filename%??}"}" != "_2" ]; then
        if [ -n "${NO_PYTHON}" ] || [ -n "${WRONG_PYTHON_COMMAND}" ]; then
            section_checkmk_failed_plugin "${agent_plugin}"
            return 1
        fi

        if [ -n "${PYTHON3}" ]; then
            echo "${PYTHON3}"
            return 0
        fi

        if [ ! -e "${filename}_2.py" ]; then
            section_checkmk_failed_plugin "${agent_plugin} (Missing Python 3 installation)"
            return 1
        fi

        # no python3 found, but python2 plugin file present
        return 1
    fi

    if [ -x "${filename%??}.py" ] && [ -n "${PYTHON3}" ]; then
        return 1
    fi

    if [ -n "${PYTHON2}" ]; then
        echo "${PYTHON2}"
        return 0
    fi

    section_checkmk_failed_plugin "${agent_plugin} (missing Python 2 installation)"
    return 1
}

run_plugins() {
    cd "${PLUGINSDIR}" || return

    if ${MK_RUN_SYNC_PARTS}; then
        for script in ./*; do
            if is_valid_plugin "${script}"; then
                if plugin_interpreter=$(get_plugin_interpreter "${script}"); then
                    # SC2086: We don't want to quote, interpreter is "nothing" if empty, not "''"
                    # shellcheck disable=SC2086
                    _log_section_time ${plugin_interpreter} "${script}"
                fi
            fi
        done
    fi

    # Call some plugins only every X'th second
    for script in [1-9]*/*; do
        if is_valid_plugin "${script}"; then
            if plugin_interpreter=$(get_plugin_interpreter "${script}"); then
                interval="${script%/*}"
                # shellcheck disable=SC2086
                _run_cached_internal "plugins_${script##*/}" "${interval}" "${interval}" $((interval * 3)) $((interval * 2)) _log_section_time ${plugin_interpreter} "${script}"
            fi
        fi
    done
}

_non_comment_lines() {
    grep -Ev '^[[:space:]]*($|#)' "${1}"
}

_mrpe_get_interval() {
    echo "${1}" | grep -E '^\([^)]*\)' | sed -n 's/^.*interval=\([^:)]*\).*$/\1/p'
}

_mrpe_normalize_spaces() {
    # watch out:
    # * [:blank:] does not include \t on AIX
    # * [:space:] does include \n on Linux
    tr -s '\t' ' '
}

run_remote_plugins() {
    configfile="${1}"
    prefix="${2}"
    [ -f "${configfile}" ] || return

    _non_comment_lines "${configfile}" | _mrpe_normalize_spaces | while read -r descr rest; do
        interval="$(_mrpe_get_interval "${rest}")"
        cmdline="${rest#\(*\) }"

        if [ -n "${prefix}" ]; then
            cmdline="${prefix} '${cmdline}'"
        fi

        if [ -z "${interval}" ]; then
            ${MK_RUN_SYNC_PARTS} && run_mrpe "${descr}" "${cmdline}"
        else
            # Sourcing the agent here is not very performant, but we need 'run_mrpe', and not all shells support exporting of functions.
            _run_cached_internal "mrpe_${descr}" "${interval}" "${interval}" $((interval * 3)) $((interval * 2)) "MK_SOURCE_AGENT=yes . '${0}'; run_mrpe \"${descr}\" \"${cmdline}\""
        fi

    done
}

run_mrpe() {
    descr="${1}"
    shift

    PLUGIN="${1%% *}"
    OUTPUT="$(eval "${MK_DEFINE_LOG_SECTION_TIME}; _log_section_time $*")"
    STATUS="$?"

    printf "<<<mrpe>>>\n"
    printf "(%s) %s %s %s" "${PLUGIN##*/}" "${descr}" "${STATUS}" "${OUTPUT}" | tr \\n \\1
    printf "\n"

    unset descr PLUGIN OUTPUT STATUS
}

#
# END COMMON AGENT CODE
#

run_runas_executor() {
    [ -f "${MK_CONFDIR}/runas.cfg" ] || return

    _non_comment_lines "${MK_CONFDIR}/runas.cfg" | while read -r type user configfile; do
        prefix=""
        if [ "${user}" != "-" ]; then
            prefix="su ${user} -c"
        fi

        # mrpe includes
        if [ "${type}" = "mrpe" ]; then
            run_remote_plugins "${configfile}" "${prefix}"

        # local and plugin includes
        elif [ "${type}" = "local" ] || [ "${type}" = "plugin" ]; then
            if ${MK_RUN_SYNC_PARTS}; then
                if [ "${type}" = "local" ]; then
                    echo "<<<local:sep(0)>>>"
                fi

                find "${configfile}" -executable -type f |
                    while read -r filename; do
                        if [ -n "${prefix}" ]; then
                            # SC2086: We don't want to quote since prefix should not be treated as a
                            # single string but as multiple arguments passed to _log_section_time
                            # shellcheck disable=SC2086
                            _log_section_time ${prefix} "${filename}"
                        else
                            _log_section_time "${filename}"
                        fi
                    done
            fi
        fi
    done
}

run_purely_synchronous_sections() {
    _log_section_time section_checkmk

    _log_section_time section_cmk_agent_ctl_status

    [ -z "${MK_SKIP_CHECKMK_AGENT_PLUGINS}" ] && _log_section_time section_checkmk_agent_plugins

    [ -z "${MK_SKIP_LABELS}" ] && _log_section_time section_labels

    [ -z "${MK_SKIP_DF}" ] && _log_section_time section_df

    [ -z "${MK_SKIP_SYSTEMD}" ] && _log_section_time section_systemd

    # Filesystem usage for ZFS
    [ -z "${MK_SKIP_ZFS}" ] && _log_section_time section_zfs

    # Check NFS mounts by accessing them with stat -f (System
    # call statfs()). If this lasts more then 2 seconds we
    # consider it as hanging. We need waitmax.
    [ -z "${MK_SKIP_NFS_MOUNTS}" ] && _log_section_time section_nfs_mounts "/proc/mounts"

    # Check mount options. Filesystems may switch to 'ro' in case
    # of a read error.
    [ -z "${MK_SKIP_MOUNTS}" ] && _log_section_time section_mounts

    [ -z "${MK_SKIP_PS}" ] && _log_section_time section_ps

    # Memory usage
    [ -z "${MK_SKIP_MEM}" ] && _log_section_time section_mem

    # Load and number of processes
    [ -z "${MK_SKIP_CPU}" ] && _log_section_time section_cpu

    # Uptime
    [ -z "${MK_SKIP_UPTIME}" ] && _log_section_time section_uptime

    # New variant: Information about speed and state in one section
    [ -z "${MK_SKIP_LNX_IF}" ] && _log_section_time section_lnx_if

    # Current state of bonding interfaces
    [ -z "${MK_SKIP_BONDING_IF}" ] && _log_section_time section_bonding_interfaces

    # Same for Open vSwitch bonding
    [ -z "${MK_SKIP_VSWITCH_BONDING}" ] && _log_section_time section_vswitch_bonding

    # Number of TCP connections in the various states
    [ -z "${MK_SKIP_TCP}" ] && _log_section_time section_tcp

    # Linux Multipathing
    [ -z "${MK_SKIP_MULTIPATHING}" ] && _log_section_time section_multipathing

    # Performancecounter Platten
    [ -z "${MK_SKIP_DISKSTAT}" ] && _log_section_time section_diskstat

    # Performancecounter Kernel
    [ -z "${MK_SKIP_KERNEL}" ] && _log_section_time section_kernel

    # RAID status of Linux software RAID
    [ -z "${MK_SKIP_MD}" ] && _log_section_time section_md

    # RAID status of Linux RAID via device mapper
    [ -z "${MK_SKIP_DM_RAID}" ] && _log_section_time section_dm_raid

    # RAID status of LSI controllers via cfggen
    [ -z "${MK_SKIP_CFGGEN}" ] && _log_section_time section_cfggen

    # RAID status of LSI MegaRAID controller via StorCLI or MegaCli. You can download that tool from:
    # https://docs.broadcom.com/docs/007.2007.0000.0000_Unified_StorCLI.zip
    [ -z "${MK_SKIP_MEGARAID}" ] && _log_section_time section_megaraid

    # RAID status of 3WARE disk controller (by Radoslaw Bak)
    [ -z "${MK_SKIP_THREE_WARE_RAID}" ] && _log_section_time section_3ware_raid

    # VirtualBox Guests. Section must always been output. Otherwise the
    # check would not be executed in case no guest additions are installed.
    # And that is something the check wants to detect
    [ -z "${MK_SKIP_VBOX_GUEST}" ] && _log_section_time section_vbox_guest

    # OpenVPN Clients. Currently we assume that the configuration # is in
    # /etc/openvpn. We might find a safer way to find the configuration later.
    [ -z "${MK_SKIP_OPENVPN}" ] && _log_section_time section_openvpn

    [ -z "${MK_SKIP_NVIDIA}" ] && _log_section_time section_nvidia

    [ -z "${MK_SKIP_DRBD}" ] && _log_section_time section_drbd

    # Heartbeat monitoring
    # Different handling for heartbeat clusters with and without CRM
    # for the resource state
    [ -z "${MK_SKIP_HEARTBEAT}" ] && _log_section_time section_heartbeat

    [ -z "${MK_SKIP_MAILQUEUE}" ] && _log_section_time section_mailqueue

    ## Check status of OMD sites and Checkmk Notification spooler
    # Welcome the ZFS check on Linux
    # We do not endorse running ZFS on linux if your vendor doesnt support it ;)
    # check zpool status
    [ -z "${MK_SKIP_ZPOOL}" ] && _log_section_time section_zpool

    # Veritas Cluster Server
    # Software is always installed in /opt/VRTSvcs.
    # Secure mode must be off to allow root to execute commands
    [ -z "${MK_SKIP_VERITAS}" ] && _log_section_time section_veritas_cluster

    ## Fileinfo-Check: put patterns for files into /etc/check_mk/fileinfo.cfg
    [ -z "${MK_SKIP_FILEINFO}" ] && _log_section_time section_fileinfo

    # Get stats about OMD monitoring cores running on this machine.
    # Since cd is a shell builtin the check does not affect the performance
    # on non-OMD machines.
    [ -z "${MK_SKIP_OMD_CORES}" ] && _log_section_time section_omd_core

    # Collect states of configured Checkmk site backup jobs
    _log_section_time section_mkbackup

    # Get statistics about monitored jobs. Below the job directory there
    # is a sub directory per user that ran a job. That directory must be
    # owned by the user so that a symlink or hardlink attack for reading
    # arbitrary files can be avoided.
    [ -z "${MK_SKIP_JOB}" ] && _log_section_time section_job

    # Gather thermal information provided e.g. by acpi
    # At the moment only supporting thermal sensors
    [ -z "${MK_SKIP_THERMAL}" ] && _log_section_time section_thermal

    # Libelle Business Shadow
    [ -z "${MK_SKIP_LIBELLE}" ] && _log_section_time section_libelle

    # HTTP Accelerator Statistics
    [ -z "${MK_SKIP_HTTP_ACCELERATOR}" ] && _log_section_time section_http_accelerator

    # Proxmox Cluster
    [ -z "${MK_SKIP_PROXMOX}" ] && _log_section_time section_proxmox

    [ -z "${MK_SKIP_HAPROXY}" ] && _log_section_time section_haproxy
}

run_partially_asynchronous_sections() {
    # Time synchronization with Chrony
    [ -z "${MK_SKIP_CHRONY}" ] && _log_section_time section_chrony

    # Hardware sensors via IPMI (need ipmitool)
    [ -z "${MK_SKIP_IPMITOOL}" ] && _log_section_time section_ipmitool

    # IPMI data via ipmi-sensors (of freeipmi). Please make sure, that if you
    # have installed freeipmi that IPMI is really support by your hardware.
    [ -z "${MK_SKIP_IPMISENSORS}" ] && _log_section_time section_ipmisensors

    # RAID controllers from areca (Taiwan)
    # cli64 can be found at ftp://ftp.areca.com.tw/RaidCards/AP_Drivers/Linux/CLI/
    [ -z "${MK_SKIP_ARECA}" ] && _log_section_time section_areca_raid

    ## Check status of OMD sites and Checkmk Notification spooler
    [ -z "${MK_SKIP_OMD}" ] && _log_section_time section_omd

    if [ -z "${MK_SKIP_TIMESYNCHRONISATION}" ]; then
        _log_section_time section_timesyncd || _log_section_time section_ntp
    fi
}

main_setup() {

    set_up_remote

    # close stdin
    exec </dev/null

    set_up_process_commandline_arguments "$@"

    # close stderr unless explicitly configured to stay open
    if "${DISABLE_STDERR:-true}"; then
        exec 2>/dev/null
    fi

    set_up_get_epoch

    set_up_current_shell

    set_variable_defaults

    announce_remote # needs MK_VARDIR!

    PATH="$(set_up_path "${PATH}")"

    set_up_profiling
    unset_locale
    detect_python
    detect_container_environment
    set_up_encryption
    set_up_disabled_sections

    export_utility_functions
}

main_sync_parts() {

    run_purely_synchronous_sections

    _log_section_time run_spooler

}

main_mixed_parts() {

    run_partially_asynchronous_sections

    run_remote_plugins "${MK_CONFDIR}/mrpe.cfg" ""

    run_runas_executor

    run_local_checks

    run_plugins
}

main_async_parts() {
    # Start new liveupdate process in background
    # Starting a new live update process will terminate the old one automatically after
    # max. 1 sec.
    run_real_time_checks
}

main_finalize_sync() {
    finalize_profiling
}

#
# BEGIN COMMON AGENT CODE
#

main() {

    while true; do

        main_setup "$@"

        (

            ${MK_RUN_SYNC_PARTS} && main_sync_parts

            (${MK_RUN_ASYNC_PARTS} || ${MK_RUN_SYNC_PARTS}) && main_mixed_parts

            ${MK_RUN_ASYNC_PARTS} && main_async_parts

            ${MK_RUN_SYNC_PARTS} && main_finalize_sync

        ) | { if ${MK_RUN_SYNC_PARTS}; then optionally_encrypt "${PASSPHRASE}" ""; else cat; fi; }

        [ "${MK_LOOP_INTERVAL}" -gt 0 ] 2>/dev/null || return 0

        sleep "${MK_LOOP_INTERVAL}"

    done

}

[ -z "${MK_SOURCE_AGENT}" ] && main "$@"