System Service Library for Python

This is a library to assist with controlling system services.

Classes

ServiceConfig

The ServiceConfig class is created to simplify/unify creation of configuration files, as these come in all types of shapes ans sizes. This currently only supports jsonarray, ini, blocks, and raw. This was originally designed because I was tired of writing a new library every time I wanted an interface for configuration files.

Parameters

• filepath - (required) The full path to the file on the system.
• filetype - (required) The type of configuration file, currently only supports jsonarray, ini, blocks, and raw.
• blocks - An array of pre-defined Block objects; may be used for loading a saved state (default: None)
• closer - The character to end each setting (default: )
• definer - The character that is used to separate the key from the value in the configuration file (default: =)
• commenter - The character that is used for creating comments

How to Use ServiceConfig

Let's take, for example, the /etc/libuser.conf file.

First, we create a ServiceConfig instance.

import serviceconf

LIBUSERCONF=serviceconf.ServiceConfig('/etc/libuser.conf','ini')

Next, we create a new block and add the related settings. Each setting that is added directly after the addition of a block is attached to that specific block.

LIBUSERCONF.add_block('import')
LIBUSERCONF.add_setting('login_defs','/etc/login.defs')
LIBUSERCONF.add_setting('default_useradd','/etc/default/useradd')

We can create additional blocks with additional settings.

LIBUSERCONF.add_block('defaults')
LIBUSERCONF.add_setting('moduledir','/etc/libuser.conf.d/modules')
LIBUSERCONF.add_setting('crypt_style','sha512')
LIBUSERCONF.save()

This produces the following:

[import]
login_defs=/etc/login.defs
default_useradd=/etc/default/useradd

[defaults]
moduledir=/etc/libuser.conf.d/modules
crypt_style=sha512

Service Config File Types

ini files

Typically, ini files have blocks that are bracketed, then groups of settings following the bracketed word. Often the settings are in the format of key = value, sometimes ending with a semi-colon: key = value;.

Example ini file

[ldap]
server = ldap.digitalocean.com
basedn = dc=example,dc=com

jsonarray

For ServiceConfig, jsonarray is actually an array of jsonarray settings. This allows for multiple configurations of the same type. While this output isn't typical, it allows for multiple settings. For example a system that allows for multiple server definitions would look like this:

[
  {
    "server": {
      "bind_address": "0.0.0.0",
      "port": "1234"
    }
  },
  {
    "server": {
      "bind_address": "0.0.0.0",
      "port": "5678"
    }
  }
]

Example jsonarray file

[
  {
    "import": {
      "login_defs": "/etc/login.defs",
      "default_useradd": "/etc/default/useradd"
    }
  },
  {
    "defaults": {
      "moduledir": "/etc/libuser.conf.d/modules",
      "crypt_style": "sha512"
    }
  }
]

blocks

A blocks definition place settings within bracketed (or braced) blocks. This isn't typical for many configuration files, but has been seen in configurations, such as Redsocks.

Example blocks file

In this example, it's also worth noting that the closer was used and set to a semi-colon.

server {
bind_address=0.0.0.0;
port=1234;
}
server {
bind_address=0.0.0.0;
port=5678;
}

ServiceApi

The ServiceApi class is created to simplify/unify control of system services via Rest-like API.

Requirements

This module requires the PolicyKit-1 package for controlling the systemd bus.

Parameters

• servicename - (required) The name of the service (sans .service). For example, if this was nginx.service, you would use servicename=nginx.

Functions

• get_sysd_manager_interface - Used for controlling the systemd bus.

Methods

dbus_action(action)

This applies the action to the service. Action must be one of start, stop, and restart.

dbus_getstate()

This gets the current state of the service. It returns a dictionary that indicates the active_state and sub_state. For example: inactive (dead) = {'active_state': 'inactive', 'sub_state': 'dead'}.

enable()

Creates the symbolic links to the service in /etc/systemd/system/multi-user.target.wants (from /lib/systemd/system/<servicename>.service). Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

disable()

Removes the symbolic links to the service in /etc/systemd/system/multi-user.target.wants (from /lib/systemd/system/<servicename>.service). Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

start()

Starts the service using the dbus_action method. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

stop()

Stops the service using the dbus_action method. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

restart()

Restarts the service using the dbus_action method. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

status()

Gets the service status using the dbus_getstate method. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

servicectl()

Controls the service using the enable, disable, start, stop, status, or restart methods. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

enable_and_start()

Uses the enable and start methods to enable the service and start the service. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).

disable_and_stop()

Uses the disable and stop methods to enable the service and start the service. Returns a dictionary that includes a message (array of strings), and a status (integer return value (0 = successful).