cc_chef.py

# Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
#
# Author: Avishai Ish-Shalom <avishai@fewbytes.com>
# Author: Mike Moulton <mike@meltmedia.com>
# Author: Juerg Haefliger <juerg.haefliger@hp.com>
#
# This file is part of cloud-init. See LICENSE file for license information.

"""Chef: module that configures, starts and installs chef."""

import itertools
import json
import logging
import os
from textwrap import dedent
from typing import List

from cloudinit import subp, temp_utils, templater, url_helper, util
from cloudinit.cloud import Cloud
from cloudinit.config import Config
from cloudinit.config.schema import MetaSchema, get_meta_doc
from cloudinit.distros import Distro
from cloudinit.settings import PER_ALWAYS

RUBY_VERSION_DEFAULT = "1.8"

CHEF_DIRS = tuple(
    [
        "/etc/chef",
        "/var/log/chef",
        "/var/lib/chef",
        "/var/cache/chef",
        "/var/backups/chef",
        "/var/run/chef",
    ]
)
REQUIRED_CHEF_DIRS = tuple(
    [
        "/etc/chef",
    ]
)

# Used if fetching chef from a omnibus style package
OMNIBUS_URL = "https://www.chef.io/chef/install.sh"
OMNIBUS_URL_RETRIES = 5

CHEF_VALIDATION_PEM_PATH = "/etc/chef/validation.pem"
CHEF_ENCRYPTED_DATA_BAG_PATH = "/etc/chef/encrypted_data_bag_secret"
CHEF_ENVIRONMENT = "_default"
CHEF_FB_PATH = "/etc/chef/firstboot.json"
CHEF_RB_TPL_DEFAULTS = {
    # These are ruby symbols...
    "ssl_verify_mode": ":verify_none",
    "log_level": ":info",
    # These are not symbols...
    "log_location": "/var/log/chef/client.log",
    "validation_key": CHEF_VALIDATION_PEM_PATH,
    "validation_cert": None,
    "client_key": "/etc/chef/client.pem",
    "json_attribs": CHEF_FB_PATH,
    "file_cache_path": "/var/cache/chef",
    "file_backup_path": "/var/backups/chef",
    "pid_file": "/var/run/chef/client.pid",
    "show_time": True,
    "encrypted_data_bag_secret": None,
}
CHEF_RB_TPL_BOOL_KEYS = frozenset(["show_time"])
CHEF_RB_TPL_PATH_KEYS = frozenset(
    [
        "log_location",
        "validation_key",
        "client_key",
        "file_cache_path",
        "json_attribs",
        "pid_file",
        "encrypted_data_bag_secret",
    ]
)
CHEF_RB_TPL_KEYS = frozenset(
    itertools.chain(
        CHEF_RB_TPL_DEFAULTS.keys(),
        CHEF_RB_TPL_BOOL_KEYS,
        CHEF_RB_TPL_PATH_KEYS,
        [
            "server_url",
            "node_name",
            "environment",
            "validation_name",
            "chef_license",
        ],
    )
)
CHEF_RB_PATH = "/etc/chef/client.rb"
CHEF_EXEC_PATH = "/usr/bin/chef-client"
CHEF_EXEC_DEF_ARGS = tuple(["-d", "-i", "1800", "-s", "20"])


frequency = PER_ALWAYS
distros = ["all"]

LOG = logging.getLogger(__name__)

meta: MetaSchema = {
    "id": "cc_chef",
    "name": "Chef",
    "title": "module that configures, starts and installs chef",
    "description": dedent(
        """\
        This module enables chef to be installed (from packages,
        gems, or from omnibus). Before this occurs, chef configuration is
        written to disk (validation.pem, client.pem, firstboot.json,
        client.rb), and required directories are created (/etc/chef and
        /var/log/chef and so-on). If configured, chef will be
        installed and started in either daemon or non-daemon mode.
        If run in non-daemon mode, post run actions are executed to do
        finishing activities such as removing validation.pem."""
    ),
    "distros": distros,
    "examples": [
        dedent(
            """
        chef:
          directories:
            - /etc/chef
            - /var/log/chef
          validation_cert: system
          install_type: omnibus
          initial_attributes:
            apache:
              prefork:
                maxclients: 100
              keepalive: off
          run_list:
            - recipe[apache2]
            - role[db]
          encrypted_data_bag_secret: /etc/chef/encrypted_data_bag_secret
          environment: _default
          log_level: :auto
          omnibus_url_retries: 2
          server_url: https://chef.yourorg.com:4000
          ssl_verify_mode: :verify_peer
          validation_name: yourorg-validator"""
        )
    ],
    "frequency": frequency,
    "activate_by_schema_keys": ["chef"],
}

__doc__ = get_meta_doc(meta)


def post_run_chef(chef_cfg):
    delete_pem = util.get_cfg_option_bool(
        chef_cfg, "delete_validation_post_exec", default=False
    )
    if delete_pem and os.path.isfile(CHEF_VALIDATION_PEM_PATH):
        os.unlink(CHEF_VALIDATION_PEM_PATH)


def get_template_params(iid, chef_cfg):
    params = CHEF_RB_TPL_DEFAULTS.copy()
    # Allow users to overwrite any of the keys they want (if they so choose),
    # when a value is None, then the value will be set to None and no boolean
    # or string version will be populated...
    for k, v in chef_cfg.items():
        if k not in CHEF_RB_TPL_KEYS:
            LOG.debug("Skipping unknown chef template key '%s'", k)
            continue
        if v is None:
            params[k] = None
        else:
            # This will make the value a boolean or string...
            if k in CHEF_RB_TPL_BOOL_KEYS:
                params[k] = util.get_cfg_option_bool(chef_cfg, k)
            else:
                params[k] = util.get_cfg_option_str(chef_cfg, k)
    # These ones are overwritten to be exact values...
    params.update(
        {
            "generated_by": util.make_header(),
            "node_name": util.get_cfg_option_str(
                chef_cfg, "node_name", default=iid
            ),
            "environment": util.get_cfg_option_str(
                chef_cfg, "environment", default="_default"
            ),
            # These two are mandatory...
            "server_url": chef_cfg["server_url"],
            "validation_name": chef_cfg["validation_name"],
        }
    )
    return params


def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
    """Handler method activated by cloud-init."""

    # If there isn't a chef key in the configuration don't do anything
    if "chef" not in cfg:
        LOG.debug(
            "Skipping module named %s, no 'chef' key in configuration", name
        )
        return

    chef_cfg = cfg["chef"]

    # Ensure the chef directories we use exist
    chef_dirs = util.get_cfg_option_list(chef_cfg, "directories")
    if not chef_dirs:
        chef_dirs = list(CHEF_DIRS)
    for d in itertools.chain(chef_dirs, REQUIRED_CHEF_DIRS):
        util.ensure_dir(d)

    vkey_path = chef_cfg.get("validation_key", CHEF_VALIDATION_PEM_PATH)
    vcert = chef_cfg.get("validation_cert")
    # special value 'system' means do not overwrite the file
    # but still render the template to contain 'validation_key'
    if vcert:
        if vcert != "system":
            util.write_file(vkey_path, vcert)
        elif not os.path.isfile(vkey_path):
            LOG.warning(
                "chef validation_cert provided as 'system', but "
                "validation_key path '%s' does not exist.",
                vkey_path,
            )

    # Create the chef config from template
    template_fn = cloud.get_template_filename("chef_client.rb")
    if template_fn:
        iid = str(cloud.datasource.get_instance_id())
        params = get_template_params(iid, chef_cfg)
        # Do a best effort attempt to ensure that the template values that
        # are associated with paths have their parent directory created
        # before they are used by the chef-client itself.
        param_paths = set()
        for k, v in params.items():
            if k in CHEF_RB_TPL_PATH_KEYS and v:
                param_paths.add(os.path.dirname(v))
        util.ensure_dirs(param_paths)
        templater.render_to_file(template_fn, CHEF_RB_PATH, params)
    else:
        LOG.warning("No template found, not rendering to %s", CHEF_RB_PATH)

    # Set the firstboot json
    fb_filename = util.get_cfg_option_str(
        chef_cfg, "firstboot_path", default=CHEF_FB_PATH
    )
    if not fb_filename:
        LOG.info("First boot path empty, not writing first boot json file")
    else:
        initial_json = {}
        if "run_list" in chef_cfg:
            initial_json["run_list"] = chef_cfg["run_list"]
        if "initial_attributes" in chef_cfg:
            initial_attributes = chef_cfg["initial_attributes"]
            for k in list(initial_attributes.keys()):
                initial_json[k] = initial_attributes[k]
        util.write_file(fb_filename, json.dumps(initial_json))

    # Try to install chef, if its not already installed...
    force_install = util.get_cfg_option_bool(
        chef_cfg, "force_install", default=False
    )
    installed = subp.is_exe(CHEF_EXEC_PATH)
    if not installed or force_install:
        run = install_chef(cloud, chef_cfg)
    elif installed:
        run = util.get_cfg_option_bool(chef_cfg, "exec", default=False)
    else:
        run = False
    if run:
        run_chef(chef_cfg)
        post_run_chef(chef_cfg)


def run_chef(chef_cfg):
    LOG.debug("Running chef-client")
    cmd = [CHEF_EXEC_PATH]
    if "exec_arguments" in chef_cfg:
        cmd_args = chef_cfg["exec_arguments"]
        if isinstance(cmd_args, (list, tuple)):
            cmd.extend(cmd_args)
        elif isinstance(cmd_args, str):
            cmd.append(cmd_args)
        else:
            LOG.warning(
                "Unknown type %s provided for chef"
                " 'exec_arguments' expected list, tuple,"
                " or string",
                type(cmd_args),
            )
            cmd.extend(CHEF_EXEC_DEF_ARGS)
    else:
        cmd.extend(CHEF_EXEC_DEF_ARGS)
    subp.subp(cmd, capture=False)


def subp_blob_in_tempfile(blob, distro: Distro, args: list, **kwargs):
    """Write blob to a tempfile, and call subp with args, kwargs. Then cleanup.

    'basename' as a kwarg allows providing the basename for the file.
    The 'args' argument to subp will be updated with the full path to the
    filename as the first argument.
    """
    args = args.copy()
    basename = kwargs.pop("basename", "subp_blob")
    # Use tmpdir over tmpfile to avoid 'text file busy' on execute
    with temp_utils.tempdir(
        dir=distro.get_tmp_exec_path(), needs_exe=True
    ) as tmpd:
        tmpf = os.path.join(tmpd, basename)
        args.insert(0, tmpf)
        util.write_file(tmpf, blob, mode=0o700)
        return subp.subp(args=args, **kwargs)


def install_chef_from_omnibus(
    distro: Distro, url=None, retries=None, omnibus_version=None
):
    """Install an omnibus unified package from url.

    @param url: URL where blob of chef content may be downloaded. Defaults to
        OMNIBUS_URL.
    @param retries: Number of retries to perform when attempting to read url.
        Defaults to OMNIBUS_URL_RETRIES
    @param omnibus_version: Optional version string to require for omnibus
        install.
    """
    if url is None:
        url = OMNIBUS_URL
    if retries is None:
        retries = OMNIBUS_URL_RETRIES

    if omnibus_version is None:
        args = []
    else:
        args = ["-v", omnibus_version]
    content = url_helper.readurl(url=url, retries=retries).contents
    return subp_blob_in_tempfile(
        distro=distro,
        blob=content,
        args=args,
        basename="chef-omnibus-install",
        capture=False,
    )


def install_chef(cloud: Cloud, chef_cfg):
    # If chef is not installed, we install chef based on 'install_type'
    install_type = util.get_cfg_option_str(
        chef_cfg, "install_type", "packages"
    )
    run = util.get_cfg_option_bool(chef_cfg, "exec", default=False)
    if install_type == "gems":
        # This will install and run the chef-client from gems
        chef_version = util.get_cfg_option_str(chef_cfg, "version", None)
        ruby_version = util.get_cfg_option_str(
            chef_cfg, "ruby_version", RUBY_VERSION_DEFAULT
        )
        install_chef_from_gems(ruby_version, chef_version, cloud.distro)
        # Retain backwards compat, by preferring True instead of False
        # when not provided/overriden...
        run = util.get_cfg_option_bool(chef_cfg, "exec", default=True)
    elif install_type == "packages":
        # This will install and run the chef-client from packages
        cloud.distro.install_packages(["chef"])
    elif install_type == "omnibus":
        omnibus_version = util.get_cfg_option_str(chef_cfg, "omnibus_version")
        install_chef_from_omnibus(
            distro=cloud.distro,
            url=util.get_cfg_option_str(chef_cfg, "omnibus_url"),
            retries=util.get_cfg_option_int(chef_cfg, "omnibus_url_retries"),
            omnibus_version=omnibus_version,
        )
    else:
        LOG.warning("Unknown chef install type '%s'", install_type)
        run = False
    return run


def get_ruby_packages(version) -> List[str]:
    # return a list of packages needed to install ruby at version
    pkgs: List[str] = ["ruby%s" % version, "ruby%s-dev" % version]
    if version == "1.8":
        pkgs.extend(("libopenssl-ruby1.8", "rubygems1.8"))
    return pkgs


def install_chef_from_gems(ruby_version, chef_version, distro):
    distro.install_packages(get_ruby_packages(ruby_version))
    if not os.path.exists("/usr/bin/gem"):
        util.sym_link("/usr/bin/gem%s" % ruby_version, "/usr/bin/gem")
    if not os.path.exists("/usr/bin/ruby"):
        util.sym_link("/usr/bin/ruby%s" % ruby_version, "/usr/bin/ruby")
    if chef_version:
        subp.subp(
            [
                "/usr/bin/gem",
                "install",
                "chef",
                "-v %s" % chef_version,
                "--no-ri",
                "--no-rdoc",
                "--bindir",
                "/usr/bin",
                "-q",
            ],
            capture=False,
        )
    else:
        subp.subp(
            [
                "/usr/bin/gem",
                "install",
                "chef",
                "--no-ri",
                "--no-rdoc",
                "--bindir",
                "/usr/bin",
                "-q",
            ],
            capture=False,
        )