Add systemd container control

This commit adds SystemdWorker class to kolla_docker ansible module.
It is used to manage container state via systemd calls.

Change-Id: I20e65a6771ebeee462a3aaaabaa5f0596bdd0581
Signed-off-by: Ivan Halomi <i.halomi@partner.samsung.com>
Signed-off-by: Martin Hiner <m.hiner@partner.samsung.com>

2 files changed, 238 insertions, 17 deletions

diff --git a/ansible/module_utils/kolla_docker_worker.py b/ansible/module_utils/kolla_docker_worker.py
index ebff465c1..8c365ca45 100644
--- a/ansible/module_utils/kolla_docker_worker.py
+++ b/ansible/module_utils/kolla_docker_worker.py
@@ -19,6 +19,7 @@ import json
 import os
 import shlex
 
+from ansible.module_utils.kolla_systemd_worker import SystemdWorker
 from distutils.version import StrictVersion
 
 COMPARE_CONFIG_CMD = ['/usr/local/bin/kolla_set_configs', '--check']
@@ -50,6 +51,8 @@ class DockerWorker(object):
         self._cgroupns_mode_supported = (
             StrictVersion(self.dc._version) >= StrictVersion('1.41'))
 
+        self.systemd = SystemdWorker(self.params)
+
     def generate_tls(self):
         tls = {'verify': self.params.get('tls_verify')}
         tls_cert = self.params.get('tls_cert'),
@@ -110,7 +113,8 @@ class DockerWorker(object):
         container = self.check_container()
         if (not container or
                 self.check_container_differs() or
-                self.compare_config()):
+                self.compare_config() or
+                self.systemd.check_unit_change()):
             self.changed = True
         return self.changed
 
@@ -469,6 +473,7 @@ class DockerWorker(object):
         self.changed = old_image_id != new_image_id
 
     def remove_container(self):
+        self.changed |= self.systemd.remove_unit_file()
         if self.check_container():
             self.changed = True
             # NOTE(jeffrey4l): in some case, docker failed to remove container
@@ -575,18 +580,6 @@ class DockerWorker(object):
             dimensions = self.parse_dimensions(dimensions)
             options.update(dimensions)
 
-        restart_policy = self.params.get('restart_policy')
-
-        if restart_policy is not None:
-            restart_policy = {'Name': restart_policy}
-            # NOTE(Jeffrey4l): MaximumRetryCount is only needed for on-failure
-            # policy
-            if restart_policy['Name'] == 'on-failure':
-                retries = self.params.get('restart_retries')
-                if retries is not None:
-                    restart_policy['MaximumRetryCount'] = retries
-            options['restart_policy'] = restart_policy
-
         if binds:
             options['binds'] = binds
 
@@ -599,6 +592,11 @@ class DockerWorker(object):
             if cgroupns_mode is not None:
                 host_config['CgroupnsMode'] = cgroupns_mode
 
+        # detached containers should only log to journald
+        if self.params.get('detach'):
+            options['log_config'] = docker.types.LogConfig(
+                type=docker.types.LogConfig.types.NONE)
+
         return host_config
 
     def _inject_env_var(self, environment_info):
@@ -637,6 +635,8 @@ class DockerWorker(object):
         self.changed = True
         options = self.build_container_options()
         self.dc.create_container(**options)
+        if self.params.get('restart_policy') != 'no':
+            self.changed |= self.systemd.create_unit_file()
 
     def recreate_or_restart_container(self):
         self.changed = True
@@ -678,7 +678,15 @@ class DockerWorker(object):
 
         if not container['Status'].startswith('Up '):
             self.changed = True
-            self.dc.start(container=self.params.get('name'))
+            if self.params.get('restart_policy') == 'no':
+                self.dc.start(container=self.params.get('name'))
+            else:
+                self.systemd.create_unit_file()
+                if not self.systemd.start():
+                    self.module.fail_json(
+                        changed=True,
+                        msg="Container timed out",
+                        **self.check_container())
 
         # We do not want to detach so we wait around for container to exit
         if not self.params.get('detach'):
@@ -806,7 +814,11 @@ class DockerWorker(object):
                     msg="No such container: {} to stop".format(name))
         elif not container['Status'].startswith('Exited '):
             self.changed = True
-            self.dc.stop(name, timeout=graceful_timeout)
+            if self.params.get('restart_policy') != 'no':
+                self.systemd.create_unit_file()
+                self.systemd.stop()
+            else:
+                self.dc.stop(name, timeout=graceful_timeout)
 
     def stop_and_remove_container(self):
         container = self.check_container()
@@ -825,8 +837,13 @@ class DockerWorker(object):
                 msg="No such container: {}".format(name))
         else:
             self.changed = True
-            self.dc.stop(name, timeout=graceful_timeout)
-            self.dc.start(name)
+            self.systemd.create_unit_file()
+
+            if not self.systemd.restart():
+                self.module.fail_json(
+                    changed=True,
+                    msg="Container timed out",
+                    **self.check_container())
 
     def create_volume(self):
         if not self.check_volume():
diff --git a/ansible/module_utils/kolla_systemd_worker.py b/ansible/module_utils/kolla_systemd_worker.py
new file mode 100644
index 000000000..2d8a59d1c
--- /dev/null
+++ b/ansible/module_utils/kolla_systemd_worker.py
@@ -0,0 +1,204 @@
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+from string import Template
+from time import sleep
+
+import dbus
+
+
+TEMPLATE = '''# ${service_name}
+# autogenerated by Kolla-Ansible
+
+[Unit]
+Description=docker ${service_name}
+After=docker.service
+Requires=docker.service
+StartLimitIntervalSec=${restart_timeout}
+StartLimitBurst=${restart_retries}
+
+[Service]
+ExecStart=/usr/bin/docker start -a ${name}
+ExecStop=/usr/bin/docker stop ${name} -t ${graceful_timeout}
+Restart=${restart_policy}
+RestartSec=${restart_duration}
+
+[Install]
+WantedBy=multi-user.target
+'''
+
+
+class SystemdWorker(object):
+    def __init__(self, params):
+        name = params.get('name', None)
+
+        # systemd is not needed
+        if not name:
+            return None
+
+        restart_policy = params.get('restart_policy', 'no')
+        if restart_policy == 'unless-stopped':
+            restart_policy = 'always'
+
+        # NOTE(hinermar): duration * retries should be less than timeout
+        # otherwise service will indefinitely try to restart.
+        # Also, correct timeout and retries values should probably be
+        # checked at the module level inside kolla_docker.py
+        restart_timeout = params.get('client_timeout', 120)
+        restart_retries = params.get('restart_retries', 10)
+        restart_duration = (restart_timeout // restart_retries) - 1
+
+        # container info
+        self.container_dict = dict(
+            name=name,
+            service_name='kolla-' + name + '-container.service',
+            engine='docker',
+            deps='docker.service',
+            graceful_timeout=params.get('graceful_timeout'),
+            restart_policy=restart_policy,
+            restart_timeout=restart_timeout,
+            restart_retries=restart_retries,
+            restart_duration=restart_duration
+        )
+
+        # systemd
+        self.manager = self.get_manager()
+        self.job_mode = 'replace'
+        self.sysdir = '/etc/systemd/system/'
+
+        # templating
+        self.template = Template(TEMPLATE)
+
+    def get_manager(self):
+        sysbus = dbus.SystemBus()
+        systemd1 = sysbus.get_object(
+            'org.freedesktop.systemd1',
+            '/org/freedesktop/systemd1'
+        )
+        return dbus.Interface(systemd1, 'org.freedesktop.systemd1.Manager')
+
+    def start(self):
+        if self.perform_action(
+            'StartUnit',
+            self.container_dict['service_name'],
+            self.job_mode
+        ):
+            return self.wait_for_unit(self.container_dict['restart_timeout'])
+        return False
+
+    def restart(self):
+        if self.perform_action(
+            'RestartUnit',
+            self.container_dict['service_name'],
+            self.job_mode
+        ):
+            return self.wait_for_unit(self.container_dict['restart_timeout'])
+        return False
+
+    def stop(self):
+        return self.perform_action(
+            'StopUnit',
+            self.container_dict['service_name'],
+            self.job_mode
+        )
+
+    def reload(self):
+        return self.perform_action(
+            'Reload',
+            self.container_dict['service_name'],
+            self.job_mode
+        )
+
+    def enable(self):
+        return self.perform_action(
+            'EnableUnitFiles',
+            [self.container_dict['service_name']],
+            False,
+            True
+        )
+
+    def perform_action(self, function, *args):
+        try:
+            getattr(self.manager, function)(*args)
+            return True
+        except Exception:
+            return False
+
+    def check_unit_file(self):
+        return os.path.isfile(
+            self.sysdir + self.container_dict['service_name']
+        )
+
+    def check_unit_change(self, new_content=''):
+        if not new_content:
+            new_content = self.generate_unit_file()
+
+        if self.check_unit_file():
+            with open(
+                self.sysdir + self.container_dict['service_name'], 'r'
+            ) as f:
+                curr_content = f.read()
+
+                # return whether there was change in the unit file
+                return curr_content != new_content
+
+        return True
+
+    def generate_unit_file(self):
+        return self.template.substitute(self.container_dict)
+
+    def create_unit_file(self):
+        file_content = self.generate_unit_file()
+
+        if self.check_unit_change(file_content):
+            with open(
+                self.sysdir + self.container_dict['service_name'], 'w'
+            ) as f:
+                f.write(file_content)
+
+            self.reload()
+            self.enable()
+            return True
+
+        return False
+
+    def remove_unit_file(self):
+        if self.check_unit_file():
+            os.remove(self.sysdir + self.container_dict['service_name'])
+            self.reload()
+
+            return True
+        else:
+            return False
+
+    def get_unit_state(self):
+        unit_list = self.manager.ListUnits()
+
+        for service in unit_list:
+            if str(service[0]) == self.container_dict['service_name']:
+                return str(service[4])
+
+        return None
+
+    def wait_for_unit(self, timeout):
+        delay = 5
+        elapsed = 0
+
+        while True:
+            if self.get_unit_state() == 'running':
+                return True
+            elif elapsed > timeout:
+                return False
+            else:
+                sleep(delay)
+                elapsed += delay