module SyncWrap::SystemDService

Support module for components which install SystemD services. Provide unit file installation with `systemctl` calls, and also provides standard enable, start, status, restart, stop, and disable commands for use in the CLI.

Host component dependencies: <Distro>

Attributes

listen_streams[W]

An array of ListenStream configuration values for systemd_socket (Default: nil -> unspecified and will raise if accessed)

systemd_service[RW]

The name of a systemd service unit file to create/rput. The name should include a “.service” suffix. Will rput the same name (or .erb extended template) under :sync_paths /etc/systemd/system. (Required for use of public interface)

systemd_socket[RW]

The name of the systemd socket unit file to create/rput for socket activation. If specified, the name should include a “.socket” suffix. Will rput the same name (or .erb extended template) under :sync_paths /etc/systemd/system.

Public Class Methods

new( opts = {} ) click to toggle source

Calls superclass method

# File lib/syncwrap/systemd_service.rb, line 49
def initialize( opts = {} )
  @systemd_service = nil
  @systemd_socket = nil
  @listen_streams = nil
  super
end

Public Instance Methods

disable() click to toggle source

Disable all systemd_units.

# File lib/syncwrap/systemd_service.rb, line 109
def disable
  require_systemd_service!
  systemctl( 'disable', *systemd_units )
end

enable() click to toggle source

Enable all systemd_units.

# File lib/syncwrap/systemd_service.rb, line 115
def enable
  require_systemd_service!
  systemctl( 'enable', *systemd_units )
end

install_units( restart_required = false ) click to toggle source

Install the systemd units files by rput_unit_files, detecting changes and performs `systemctl` daemon-reload, (re-)enable, and restart or start as required. If restart_required evaluates to true, for example given other external changes, a restart is mandated.

# File lib/syncwrap/systemd_service.rb, line 63
def install_units( restart_required = false )
  require_systemd_service!
  units_d = rput_unit_files

  sock_d = systemd_socket &&
           units_d.find { |_,f| File.basename( f ) == systemd_socket }

  if !units_d.empty?
    systemctl( 'daemon-reload' )
    systemctl( 'reenable', *systemd_units )
  end

  if ( restart_required || !units_d.empty? )
    restart( with_socket: !!sock_d )
  else
    start
  end

  units_d
end

restart( opts = {} ) click to toggle source

Restart the service. If option :with_socket is passed as true, restart all systemd_units which includes systemd_socket if present.

# File lib/syncwrap/systemd_service.rb, line 93
def restart( opts = {} )
  require_systemd_service!
  if opts[ :with_socket ]
    systemctl( 'restart', *systemd_units )
  else
    systemctl( 'restart', systemd_service )
  end
end

start() click to toggle source

Start all systemd_units.

# File lib/syncwrap/systemd_service.rb, line 85
def start
  require_systemd_service!
  systemctl( 'start', *systemd_units )
end

status() click to toggle source

Output status of systemd_units (useful via CLI with –verbose). Exit codes 0-3 are accepted from `systemctl`, since these will be returned in normal operational contexts, for example, when services are intentionally and manually stopped. Exit on error is also disabled, which may be relevent for merged commands.

# File lib/syncwrap/systemd_service.rb, line 125
def status
  require_systemd_service!
  systemctl_status( *systemd_units, error: false, accept: [0,1,2,3] )
end

stop() click to toggle source

Stop all systemd_units.

# File lib/syncwrap/systemd_service.rb, line 103
def stop
  require_systemd_service!
  systemctl( 'stop', *systemd_units )
end

Protected Instance Methods

listen_streams() click to toggle source

# File lib/syncwrap/systemd_service.rb, line 45
def listen_streams
  @listen_streams or raise "#{self.class.name}#listen_streams not specified"
end

require_systemd_service!() click to toggle source

Raise if #systemd_service not specified.

# File lib/syncwrap/systemd_service.rb, line 150
def require_systemd_service!
  raise "#{self.class.name}#systemd_service not set" unless systemd_service
end

rput_unit_files() click to toggle source

Perform rput of systemd unit files and return changes array. This can be overridden, for example to use system provided units (no-op and return `[]`) or for additional “drop-in” config files (e.g. foo.service.d/overrides.conf). Any changes signal that the service (or if included in changes, the socket) should be restarted.

# File lib/syncwrap/systemd_service.rb, line 138
def rput_unit_files
  srcs = systemd_units.map { |u| "/etc/systemd/system/" + u }
  rput( *srcs, "/etc/systemd/system/", user: :root )
end

systemd_units() click to toggle source

Return Array of the unit names that were specified (not nil) via systemd_service and systemd_socket.

# File lib/syncwrap/systemd_service.rb, line 145
def systemd_units
  [systemd_socket, systemd_service].compact
end