Add sv module to manage runit services #20181 (#20471)

* Add sv module to manage runit services

* Add mission `restarted` method

lib/ansible/modules/system/sv.py

@@ -0,0 +1,300 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+#
+# (c) 2015, Brian Coca <bcoca@ansible.com>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>
+
+ANSIBLE_METADATA = {'status': ['stableinterface'],
+                    'supported_by': 'community',
+                    'version': '1.0'}
+
+# This is a modification of @bcoca's `svc` module
+
+DOCUMENTATION = '''
+---
+module: sv
+author: "James Sumners (@jsumners)"
+version_added: "2.3"
+short_description:  Manage runit services.
+description:
+    - Controls runit services on remote hosts using the sv utility.
+options:
+    name:
+        required: true
+        description:
+            - Name of the service to manage.
+    state:
+        required: false
+        choices: [ started, stopped, restarted, killed, reloaded, once ]
+        description:
+            - C(started)/C(stopped) are idempotent actions that will not run
+              commands unless necessary.  C(restarted) will always bounce the
+              service (sv restart) and C(killed) will always bounce the service (sv force-stop).
+              C(reloaded) will send a HUP (sv reload).
+              C(once) will run a normally downed svc once (sv once), not really
+              an idempotent operation.
+    enabled:
+        required: false
+        choices: [ "yes", "no" ]
+        description:
+            - Wheater the service is enabled or not, if disabled it also implies stopped.
+    service_dir:
+        required: false
+        default: /var/service
+        description:
+            - directory runsv watches for services
+    service_src:
+        required: false
+        default: /etc/sv
+        description:
+            - directory where services are defined, the source of symlinks to service_dir.
+'''
+
+EXAMPLES = '''
+# Example action to start sv dnscache, if not running
+ - sv:
+    name: dnscache
+    state: started
+
+# Example action to stop sv dnscache, if running
+ - sv:
+    name: dnscache
+    state: stopped
+
+# Example action to kill sv dnscache, in all cases
+ - sv:
+    name: dnscache
+    state: killed
+
+# Example action to restart sv dnscache, in all cases
+ - sv:
+    name: dnscache
+    state: restarted
+
+# Example action to reload sv dnscache, in all cases
+ - sv:
+    name: dnscache
+    state: reloaded
+
+# Example using alt sv directory location
+ - sv:
+    name: dnscache
+    state: reloaded
+    service_dir: /run/service
+'''
+
+import platform
+import shlex
+from ansible.module_utils.pycompat24 import get_exception
+from ansible.module_utils.basic import *
+
+def _load_dist_subclass(cls, *args, **kwargs):
+    '''
+    Used for derivative implementations
+    '''
+    subclass = None
+
+    distro = kwargs['module'].params['distro']
+
+    # get the most specific superclass for this platform
+    if distro is not None:
+        for sc in cls.__subclasses__():
+            if sc.distro is not None and sc.distro == distro:
+                subclass = sc
+    if subclass is None:
+        subclass = cls
+
+    return super(cls, subclass).__new__(subclass)
+
+class Sv(object):
+    """
+    Main class that handles daemontools, can be subclassed and overridden in case
+    we want to use a 'derivative' like encore, s6, etc
+    """
+
+
+    #def __new__(cls, *args, **kwargs):
+    #    return _load_dist_subclass(cls, args, kwargs)
+
+
+
+    def __init__(self, module):
+        self.extra_paths = [ ]
+        self.report_vars = ['state', 'enabled', 'svc_full', 'src_full', 'pid', 'duration', 'full_state']
+
+        self.module         = module
+
+        self.name           = module.params['name']
+        self.service_dir    = module.params['service_dir']
+        self.service_src    = module.params['service_src']
+        self.enabled        = None
+        self.full_state     = None
+        self.state          = None
+        self.pid            = None
+        self.duration       = None
+
+        self.svc_cmd        = module.get_bin_path('sv', opt_dirs=self.extra_paths)
+        self.svstat_cmd     = module.get_bin_path('sv', opt_dirs=self.extra_paths)
+        self.svc_full = '/'.join([ self.service_dir, self.name ])
+        self.src_full = '/'.join([ self.service_src, self.name ])
+
+        self.enabled = os.path.lexists(self.svc_full)
+        if self.enabled:
+            self.get_status()
+        else:
+            self.state = 'stopped'
+
+
+    def enable(self):
+        if os.path.exists(self.src_full):
+            try:
+                os.symlink(self.src_full, self.svc_full)
+            except OSError:
+                e = get_exception()
+                self.module.fail_json(path=self.src_full, msg='Error while linking: %s' % str(e))
+        else:
+            self.module.fail_json(msg="Could not find source for service to enable (%s)." % self.src_full)
+
+    def disable(self):
+        self.execute_command([self.svc_cmd,'force-stop',self.src_full])
+        try:
+            os.unlink(self.svc_full)
+        except OSError:
+            e = get_exception()
+            self.module.fail_json(path=self.svc_full, msg='Error while unlinking: %s' % str(e))
+
+    def get_status(self):
+        (rc, out, err) = self.execute_command([self.svstat_cmd, 'status', self.svc_full])
+
+        if err is not None and err:
+            self.full_state = self.state = err
+        else:
+            self.full_state = out
+
+            m = re.search('\(pid (\d+)\)', out)
+            if m:
+                self.pid = m.group(1)
+
+            m = re.search(' (\d+)s', out)
+            if m:
+                self.duration = m.group(1)
+
+            if re.search('run:', out):
+                self.state = 'started'
+            elif re.search('down:', out):
+                self.state = 'stopped'
+            else:
+                self.state = 'unknown'
+                return
+
+    def started(self):
+        return self.start()
+
+    def start(self):
+        return self.execute_command([self.svc_cmd, 'start', self.svc_full])
+
+    def stopped(self):
+        return self.stop()
+
+    def stop(self):
+        return self.execute_command([self.svc_cmd, 'stop', self.svc_full])
+
+    def once(self):
+        return self.execute_command([self.svc_cmd, 'once', self.svc_full])
+
+    def reloaded(self):
+        return self.reload()
+
+    def reload(self):
+        return self.execute_command([self.svc_cmd, 'reload', self.svc_full])
+
+    def restarted(self):
+        return self.restart()
+
+    def restart(self):
+        return self.execute_command([self.svc_cmd, 'restart', self.svc_full])
+
+    def killed(self):
+        return self.kill()
+
+    def kill(self):
+        return self.execute_command([self.svc_cmd, 'force-stop', self.svc_full])
+
+    def execute_command(self, cmd):
+        try:
+            (rc, out, err) = self.module.run_command(' '.join(cmd))
+        except Exception:
+            e = get_exception()
+            self.module.fail_json(msg="failed to execute: %s" % str(e))
+        return (rc, out, err)
+
+    def report(self):
+        self.get_status()
+        states = {}
+        for k in self.report_vars:
+            states[k] = self.__dict__[k]
+        return states
+
+# ===========================================
+# Main control flow
+
+def main():
+    module = AnsibleModule(
+        argument_spec = dict(
+            name = dict(required=True),
+            state = dict(choices=['started', 'stopped', 'restarted', 'killed', 'reloaded', 'once']),
+            enabled = dict(required=False, type='bool'),
+            dist = dict(required=False, default='runit'),
+            service_dir = dict(required=False, default='/var/service'),
+            service_src = dict(required=False, default='/etc/sv'),
+        ),
+        supports_check_mode=True,
+    )
+
+    module.run_command_environ_update = dict(LANG='C', LC_ALL='C', LC_MESSAGES='C', LC_CTYPE='C')
+
+    state = module.params['state']
+    enabled = module.params['enabled']
+
+    sv = Sv(module)
+    changed = False
+    orig_state = sv.report()
+
+    if enabled is not None and enabled != sv.enabled:
+        changed = True
+        if not module.check_mode:
+            try:
+                if enabled:
+                    sv.enable()
+                else:
+                    sv.disable()
+            except (OSError, IOError):
+                e = get_exception()
+                module.fail_json(msg="Could not change service link: %s" % str(e))
+
+    if state is not None and state != sv.state:
+        changed = True
+        if not module.check_mode:
+            getattr(sv,state)()
+
+    module.exit_json(changed=changed, sv=sv.report())
+
+
+
+
+if __name__ == '__main__':
+    main()