Mount tool as kadalu subcommand and added a mount script

```
kadalu volfile get client mycluster/vol1 -o ./vol1.vol
mount -t kadalu ./vol1.vol /mnt/vol1 -o log-file=./mnt-vol1.log
kadalu mount ./vol1 /mnt/vol1 -o log-file=./mnt-vol1.log
```

Yet to add support to fetch Volfile from the server.

Signed-off-by: Aravinda Vishwanathapura <aravinda@kadalu.io>

.github/workflows/on-release-tag.yml

@@ -70,3 +70,11 @@ jobs:
           tag: ${{ github.ref }}
           overwrite: true
           file_glob: true
+      - name: Upload mount.kadalu script to the release
+        uses: svenstaro/upload-release-action@v2
+        with:
+          repo_token: ${{ secrets.GITHUB_TOKEN }}
+          file: extra/mount.kadalu
+          tag: ${{ github.ref }}
+          overwrite: true
+          file_glob: true

.gitignore

@@ -6,4 +6,6 @@ bin
 *.dwarf
 tmp
 __pycache__
-*.pyc
+*.pyc
+*.pid
+*.log

extra/mount.kadalu

@@ -0,0 +1,4 @@
+#!/bin/sh
+
+# Pass all the arguments to Kadalu CLI
+kadalu mount "$@";

mgr/src/cmds/mount.cr

@@ -0,0 +1,37 @@
+require "./helpers"
+require "./mount_script"
+
+MOUNT_BANNER = "
+Usage: kadalu mount SERVER:/CLUSTER/VOLUME MOUNT_PATH [arguments]
+       kadalu mount VOLFILE_PATH MOUNT_PATH [arguments]
+       kadalu mount SERVER:/CLUSTER/VOLUME@SNAPNAME MOUNT_PATH [arguments]
+       kadalu mount SERVER:/CLUSTER/VOLUME/SUBDIR MOUNT_PATH [arguments]
+"
+
+struct MountArgs
+  property options = ""
+end
+
+class Args
+  property mount_args = MountArgs.new
+end
+
+command "mount", "Mount the Kadalu Storage Volume" do |parser, args|
+  parser.banner = MOUNT_BANNER
+  parser.on("-o OPTIONS", "--options=OPTIONS", "Mount Options(comma seperated)") do |opts|
+    args.mount_args.options = opts
+  end
+  parser.on("-V", "Show Version information") do
+    puts "Kadalu Storage Mount Script - #{VERSION}"
+    exit
+  end
+end
+
+handler "mount" do |args|
+  command_error "ERROR: Invalid arguments" if args.pos_args.size != 2
+
+  volume, mount_path = args.pos_args
+  mount_path = mount_path.rstrip("/")
+
+  MountKadalu.run(volume, mount_path, args.mount_args.options)
+end

mgr/src/cmds/mount_script.cr

@@ -0,0 +1,231 @@
+require "option_parser"
+
+FUSE_MOUNT_OPTIONS            = %w[atime noatime diratime nodiratime relatime norelatime strictatime nostrictatime lazyatime nolazyatime dev nodev exec noexec suid nosuid auto_unmount]
+FUSE_MOUNT_OPTIONS_WITH_VALUE = %w[context fscontext defcontext rootcontext]
+OPTIONS_NOT_HANDLED           = %w[async sync dirsync mand nomand silent loud iversion noiversion nofail]
+
+# these ones(auto,noauto,_netdev) are interpreted during system initialization
+IGNORE_OPTIONS     = %w[rw auto noauto _netdev]
+OPTIONS_WITH_VALUE = %w[log-level log-file transport direct-io-mode volume-name volume-id subdir-mount volfile-check server-port attribute-timeout entry-timeout negative-timeout gid-timeout lru-limit invalidate-limit fetch-attempts background-qlen congestion-threshold oom-score-adj xlator-option fuse-mountopts use-readdirp fopen-keep-cache event-history reader-thread-count auto-invalidation no-root-squash root-squash kernel-writeback-cache attr-times-granularity dump-fuse fuse-flush-handle-interrupt fuse-dev-eperm-ratelimit-ns halo-max-latency halo-max-replicas halo-min-replicas process-name fopen-keep-cache io-engine backup-volfile-servers backupvolfile-server] + FUSE_MOUNT_OPTIONS_WITH_VALUE
+
+OPTIONS_WITHOUT_VALUE = %w[ro acl selinux worm enable-ino32 mem-accounting aux-gfid-mount thin-client resolve-gids localtime-logging global-threading fopen-keep-cache] + FUSE_MOUNT_OPTIONS + OPTIONS_NOT_HANDLED + IGNORE_OPTIONS
+
+LOG_LEVELS   = %w[CRITICAL ERROR WARNING INFO DEBUG TRACE NONE]
+OPTION_ALIAS = {
+  "ro"             => "read-only",
+  "transport"      => "volfile-server-transport",
+  "volume-id"      => "volfile-id",
+  "server-port"    => "volfile-server-port",
+  "fetch-attempts" => "volfile-max-fetch-attempts",
+}
+
+# TODO: Handle below option
+#  x-*)
+# # comments or userspace application-specific options, drop them
+
+module MountKadalu
+  @@glusterfs_cmd = Process.find_executable("glusterfs")
+  @@options = Hash(String, String).new
+
+  def self.error(message)
+    STDERR.puts message
+    exit 1
+  end
+
+  # TODO: Improve this Function and remove below line
+  # ameba:disable Metrics/CyclomaticComplexity
+  def self.validate_and_add_option(opt_name, opt_value)
+    new_name = opt_name
+    if OPTION_ALIAS[opt_name]?
+      new_name = OPTION_ALIAS[opt_name]
+    end
+
+    new_name = "" if IGNORE_OPTIONS.includes?(new_name)
+
+    case new_name
+    when "log-level"
+      error "Invalid Log level(#{opt_name}=#{opt_value}" if LOG_LEVELS.includes?(opt_value.upcase)
+      add_option("--#{new_name}", opt_value.upcase)
+    when "subdir-mount"
+      add_option("--#{new_name}", "/#{opt_value.lstrip("/")}")
+    when "root-squash"
+      if ["no", "off", "disable", "false"].includes?(opt_value.downcase)
+        add_option("--no-root-squash")
+      end
+    when "no-root-squash"
+      if ["yes", "on", "enable", "true"].includes?(opt_value.downcase)
+        add_option("--no-root-squash")
+      end
+    when "halo-max-latency", "halo-max-replicas", "halo-min-replicas"
+      add_option("--xlator-option", "*replicate*.#{new_name}=#{opt_value}")
+    when "volfile-check"
+      add_option("--volfile-check")
+    when "volfile-server-transport"
+      add_option("--volfile-id", "#{@@options["--volfile-id"]}.#{opt_value}") if @@options["--volfile-id"]?
+      add_option("--#{new_name}", opt_value)
+    when "volfile-id"
+      add_option("--volfile-id", "#{opt_value}.#{@@options["--volfile-server-transport"]}") if @@options["--volfile-server-transport"]?
+    when "fopen-keep-cache"
+      add_option("--fopen-keep-cache", opt_value == "" ? "true" : opt_value)
+    when "fuse-mountopts"
+      if @@options["--fuse-mountopts"]?.nil?
+        add_option("--fuse-mountopts", opt_value)
+      else
+        add_option("--fuse-mountopts", "#{@@options["--fuse-mountopts"]},#{opt_value}")
+      end
+    else
+      add_option("--#{new_name}", opt_value)
+    end
+  end
+
+  def self.parse_options(raw_options)
+    raw_options.split(",").each do |opt|
+      opt = opt.strip
+      parts = opt.split("=")
+      opt_name = parts[0].strip
+      opt_value = parts.size > 1 ? parts[1].strip : ""
+
+      if opt_value != ""
+        error "Invalid Option: #{opt}" unless OPTIONS_WITH_VALUE.includes?(opt_name)
+        error "Option doesn't take values: #{opt}" if OPTIONS_WITHOUT_VALUE.includes?(opt_name)
+      else
+        error "Invalid Option: #{opt}" unless OPTIONS_WITHOUT_VALUE.includes?(opt_name)
+      end
+
+      STDERR.puts "mount option '#{opt_name}' is not handled (yet?)" if OPTIONS_NOT_HANDLED.includes?(opt_name)
+
+      # standard mount options to pass to the kernel
+      if FUSE_MOUNT_OPTIONS.includes?(opt_name)
+        if @@options["--fuse-mountopts"]?.nil?
+          add_option("--fuse-mountopts", opt_name)
+        else
+          add_option("--fuse-mountopts", "#{@@options["--fuse-mountopts"]},#{opt_name}")
+        end
+      elsif FUSE_MOUNT_OPTIONS_WITH_VALUE.includes?(opt_name)
+        if @@options["--fuse-mountopts"]?.nil?
+          add_option("--fuse-mountopts", "#{opt_name}=\"#{opt_value}\"")
+        else
+          add_option("--fuse-mountopts", "#{@@options["--fuse-mountopts"]},#{opt_name}=\"#{opt_value}\"")
+        end
+      else
+        validate_and_add_option(opt_name, opt_value)
+      end
+    end
+  end
+
+  def self.validate_mount_path(mount_path)
+    error "ERROR: Cannot mount over root" if mount_path == ""
+    error "ERROR: Cannot mount over /tmp" if mount_path == "/tmp"
+    error "ERROR: Mount point does not exist" unless File.exists?(mount_path)
+    error "ERROR: Mount path is not empty" unless Dir.children(mount_path).size == 0
+
+    # TODO: Validate if already mounted
+    # TODO: Validate if the mount path is another mount
+    # TODO: Check recursive mount
+  end
+
+  def self.add_option(opt_name, opt_value = "")
+    @@options[opt_name] = opt_value
+  end
+
+  def self.execute(cmd, args)
+    stdout = IO::Memory.new
+    stderr = IO::Memory.new
+    status = Process.run(cmd, args: args, output: stdout, error: stderr)
+    if status.success?
+      {status.exit_code, stdout.to_s, ""}
+    else
+      {status.exit_code, "", stderr.to_s}
+    end
+  end
+
+  # TODO: Improve this Function and remove below line
+  # ameba:disable Metrics/CyclomaticComplexity
+  def self.run(volume, mount_path, raw_options)
+    if @@glusterfs_cmd.nil?
+      STDERR.puts "glusterfs client is not installed"
+      exit 1
+    end
+
+    unless Process.find_executable("getfattr")
+      STDERR.puts "WARNING: getfattr not found, certain checks will be skipped.."
+    end
+
+    hostname = ""
+    cluster_name = ""
+    volume_name = ""
+    volfile_path = ""
+
+    if File.exists?(volume)
+      volfile_path = volume
+    else
+      # Example: server1.example.com:mycluster
+      hostname, _, cluster_volume_name = volume.rpartition(":")
+
+      error "Hostname not provided" if hostname == ""
+      cluster_name, _, volume_name = cluster_volume_name.rpartition("/")
+      cluster_name = cluster_name.strip("/")
+
+      error "Cluster name is not provided" if cluster_name == ""
+      error "Volume name is not provided" if volume_name == ""
+    end
+
+    validate_mount_path(mount_path)
+
+    # Snapshot Volume mount is read only
+    # Also change the Volume name as understood by glusterfs
+    if volume_name.includes?('@')
+      add_option("--read-only")
+      parts = volume_name.split("@")
+      # /snaps/<snapname>/<volname> format
+      volume_name = "/snaps/#{parts[1]}/#{parts[0]}"
+    end
+
+    # If Subdirectory is specified
+    volume_name, _, subdir = volume_name.partition("/")
+    add_option("--subdir-mount", "/#{subdir}") if subdir != ""
+
+    # TODO: Validate Hostname
+    # TODO: Handle Backup Volfile servers
+    if volfile_path == ""
+      add_option("--volfile-server", hostname)
+      add_option("--volume-id", "/#{volume_name}")
+    else
+      add_option("--volfile", volfile_path)
+    end
+
+    parse_options(raw_options) unless raw_options.strip == ""
+
+    # Set Process name
+    if @@options["--process-name"]?
+      add_option("--process-name", "fuse.kadalu.#{@@options["--process-name"]}")
+    else
+      add_option("--process-name", "fuse.kadalu")
+    end
+
+    add_option(mount_path)
+
+    # TODO: Handle Updatedb settings
+
+    args = [] of String
+    @@options.each do |name, value|
+      if value == ""
+        args << name
+      else
+        args << "#{name}=#{value}"
+      end
+    end
+
+    rc, _, err = execute(@@glusterfs_cmd.not_nil!, args)
+
+    # If this is true, then glusterfs process returned error without
+    # getting daemonized. We have made sure the logs are posted to
+    # 'stderr', so no need to point them to logfile.
+    unless rc == 0
+      STDERR.puts err.strip
+      error "Mounting glusterfs on $mount_point failed."
+    end
+
+    # TODO: Mount path inode check
+  end
+end

tests/install.t

@@ -12,6 +12,7 @@ nodes.each do |node|
   TEST "docker cp ./mgr/bin/kadalu #{node}:/usr/sbin/kadalu"
   TEST "docker cp extra/kadalu-mgr.service #{node}:/lib/systemd/system/"
   TEST "docker cp extra/kadalu-agent.service #{node}:/lib/systemd/system/"
+  TEST "docker cp extra/mount.kadalu #{node}:/sbin/mount.kadalu"
 end
 
 # Sanity test