New Swarm backend based on the latest Docker Python API

Adds as a benefit:
- support for TLS
- no more monitor thread, as the event stream was unreliable

requirements.txt

 Jinja2>=2.8
 requests>=2.9.1
-docker-py==1.8.1
+docker>=2.1.0
 tornado>=4.3
 kazoo>=2.2.1
 humanfriendly

zoe_lib/applications.py

@@ -151,18 +151,12 @@ def _service_check(data):
             if not isinstance(volume[2], bool):
                 raise InvalidApplicationDescription(msg='readonly volume item (third) must be a boolean: {}'.format(volume[2]))
 
-    if 'constraints' in data and not hasattr(data['constraints'], '__iter__'):
-        raise InvalidApplicationDescription(msg='networks should be an iterable')
-
-    if get_conf().backend == 'Kubernetes':
-        if 'replicas' not in data:
-            data['replicas'] = 1
-
-        try:
-            int(data['replicas'])
-        except ValueError:
-            raise InvalidApplicationDescription(msg="replicas field should be an int")
-
+    if 'replicas' not in data:
+        data['replicas'] = 1
+    try:
+        int(data['replicas'])
+    except ValueError:
+        raise InvalidApplicationDescription(msg="replicas field should be an int")
 
 
 def _port_check(data):

zoe_lib/config.py

@@ -49,7 +49,6 @@ def load_configuration(test_conf=None):
 
         # Common options
         argparser.add_argument('--debug', action='store_true', help='Enable debug output')
-        argparser.add_argument('--swarm', help='Swarm/Docker API endpoint (ex.: zk://zk1:2181,zk2:2181 or http://swarm:2380)', default='http://localhost:2375')
         argparser.add_argument('--deployment-name', help='name of this Zoe deployment', default='prod')
 
         argparser.add_argument('--dbname', help='DB name', default='zoe')
@@ -94,7 +93,16 @@ def load_configuration(test_conf=None):
         argparser.add_argument('--scheduler-class', help='Scheduler class to use for scheduling ZApps', choices=['ZoeSimpleScheduler', 'ZoeElasticScheduler'], default='ZoeSimpleScheduler')
         argparser.add_argument('--scheduler-policy', help='Scheduler policy to use for scheduling ZApps', choices=['FIFO', 'SIZE'], default='FIFO')
 
-        argparser.add_argument('--backend', choices=['OldSwarm', 'Kubernetes'], default='OldSwarm')
+        argparser.add_argument('--backend', choices=['Swarm', 'OldSwarm', 'Kubernetes'], default='Swarm')
+
+        # Docker Swarm backend options
+        argparser.add_argument('--backend-swarm-url', help='Swarm/Docker API endpoint (ex.: zk://zk1:2181,zk2:2181 or http://swarm:2380)', default='http://localhost:2375')
+        argparser.add_argument('--backend-swarm-zk-path', help='Swarm/Docker optional ZooKeeper path for Swarm Znodes', default='/docker')
+        argparser.add_argument('--backend-swarm-tls-cert', help='Docker TLS certificate file', default='cert.pem')
+        argparser.add_argument('--backend-swarm-tls-key', help='Docker TLS private key file', default='key.pem')
+        argparser.add_argument('--backend-swarm-tls-ca', help='Docker TLS CA certificate file', default='ca.pem')
+
+        # Kubernetes backend
         argparser.add_argument('--kube-config-file', help='Kubernetes configuration file', default='/opt/zoe/kube.conf')
 
         argparser.add_argument('--cookie-secret', help='secret used to encrypt cookies', default='changeme')

zoe_lib/exceptions.py

@@ -46,8 +46,3 @@ class InvalidApplicationDescription(ZoeAPIException):
     """
     def __init__(self, msg):
         super().__init__("Error: " + msg)
-
-
-class ZoeNotEnoughResourcesException(ZoeLibException):
-    """Service failed to start due to not enough available resources."""
-    pass

zoe_lib/state/__init__.py

@@ -18,4 +18,4 @@
 from zoe_lib.state.base import Base
 from zoe_lib.state.execution import Execution
 from zoe_lib.state.sql_manager import SQLManager
-from zoe_lib.state.service import Service
+from zoe_lib.state.service import Service, VolumeDescription

zoe_lib/state/service.py

@@ -196,3 +196,8 @@ class Service:
     def is_dead(self):
         """Returns True if this service is not running."""
         return self.backend_status == self.BACKEND_DESTROY_STATUS or self.backend_status == self.BACKEND_OOM_STATUS or self.backend_status == self.BACKEND_DIE_STATUS
+
+    @property
+    def unique_name(self):
+        """Returns a name for this service that is unique across multiple Zoe instances running on the same backend."""
+        return self.name + '-' + str(self.execution_id) + '-' + get_conf().deployment_name

zoe_master/backends/base.py

@@ -15,10 +15,9 @@
 
 """The base class that all backends should implement."""
 
-from typing import Dict
-
-from zoe_lib.state import Execution, Service
+from zoe_lib.state import Service
 from zoe_master.stats import ClusterStats
+from zoe_master.backends.service_instance import ServiceInstance
 
 
 class BaseBackend:
@@ -34,8 +33,17 @@ class BaseBackend:
         """Performs a clean shutdown of the resources used by Swarm backend. Any threads that where started in the init() method should be terminated here. This method will be called when Zoe shuts down."""
         raise NotImplementedError
 
-    def spawn_service(self, execution: Execution, service: Service, env_subst_dict: Dict):
-        """Create a container for a service."""
+    def spawn_service(self, service_instance: ServiceInstance):
+        """Create a container for a service.
+
+        The backend translates all the configuration parameters given in the ServiceInstance object into backend-specific container options and starts the container.
+
+        This function should either:
+
+        * raise ``ZoeStartExecutionRetryException`` in case a temporary error is generated
+        * raise ``ZoeStartExecutionFatalException`` in case a fatal error is generated
+        * return a backend-specific ID that will be used later by Zoe to interact with the running container
+        """
         raise NotImplementedError
 
     def terminate_service(self, service: Service) -> None:

zoe_master/backends/common.py

@@ -21,6 +21,8 @@ from zoe_lib.config import get_conf
 from zoe_lib.state import Service, Execution
 from zoe_master.backends.proxy import gen_proxypath, JUPYTER_NOTEBOOK, MONGO_EXPRESS, JUPYTER_PORT, MONGO_PORT
 from zoe_master.exceptions import ZoeStartExecutionFatalException
+from zoe_master.workspace.filesystem import ZoeFSWorkspace
+
 
 def gen_environment(execution: Execution, service: Service, env_subst_dict: Dict):
     """ Generate a dictionary containing the current cluster status (before the new container is spawned)
@@ -36,6 +38,7 @@ def gen_environment(execution: Execution, service: Service, env_subst_dict: Dict
             raise ZoeStartExecutionFatalException("Service {} has wrong environment expression")
         env_list.append((env_name, env_value))
 
+    # FIXME this code needs to be removed/changed to be generic
     #if 'jupyter' in service.image_name:
     env_list.append((JUPYTER_NOTEBOOK, gen_proxypath(execution, service) + '/' + JUPYTER_PORT))
     #elif 'mongo-express' in service.image_name:
@@ -47,4 +50,30 @@ def gen_environment(execution: Execution, service: Service, env_subst_dict: Dict
     env_list.append(('SERVICE_NAME', service.name))
     env_list.append(('PROXY_PATH', get_conf().proxy_path))
 
+    fswk = ZoeFSWorkspace()
+    env_list.append(('ZOE_WORKSPACE', fswk.get_mountpoint()))
     return env_list
+
+
+def gen_volumes(service_: Service, execution: Execution):
+    """Return the list of default volumes to be added to all containers."""
+    vol_list = []
+    fswk = ZoeFSWorkspace()
+    wk_vol = fswk.get(execution.user_id)
+
+    vol_list.append(wk_vol)
+
+    return vol_list
+
+
+def gen_labels(service: Service, execution: Execution):
+    """Generate container labels, useful for identifying containers in monitoring systems."""
+    return {
+        'zoe_execution_name': execution.name,
+        'zoe_execution_id': str(execution.id),
+        'zoe_service_name': service.name,
+        'zoe_service_id': str(service.id),
+        'zoe_owner': execution.user_id,
+        'zoe_deployment_name': get_conf().deployment_name,
+        'zoe_type': 'app_service'
+    }

zoe_master/backends/interface.py

@@ -22,9 +22,23 @@ from zoe_lib.config import get_conf
 from zoe_lib.state import Execution, Service
 
 from zoe_master.backends.base import BaseBackend
-from zoe_master.backends.old_swarm.backend import OldSwarmBackend
-from zoe_master.backends.kubernetes.backend import KubernetesBackend
-from zoe_master.exceptions import ZoeStartExecutionFatalException, ZoeStartExecutionRetryException
+from zoe_master.backends.service_instance import ServiceInstance
+from zoe_master.exceptions import ZoeStartExecutionFatalException, ZoeStartExecutionRetryException, ZoeException
+
+try:
+    from zoe_master.backends.old_swarm.backend import OldSwarmBackend
+except ImportError as ex:
+    OldSwarmBackend = None
+
+try:
+    from zoe_master.backends.swarm.backend import SwarmBackend
+except ImportError as ex:
+    SwarmBackend = None
+
+try:
+    from zoe_master.backends.kubernetes.backend import KubernetesBackend
+except ImportError:
+    KubernetesBackend = None
 
 log = logging.getLogger(__name__)
 
@@ -33,9 +47,17 @@ def _get_backend() -> BaseBackend:
     """Return the right backend instance by reading the global configuration."""
     backend_name = get_conf().backend
     if backend_name == 'OldSwarm':
+        if OldSwarmBackend is None:
+            raise ZoeException('The OldSwarm backend requires docker python version < 2')
         return OldSwarmBackend(get_conf())
     elif backend_name == 'Kubernetes':
+        if KubernetesBackend is None:
+            raise ZoeException('The Kubernetes backend requires the pykube module')
         return KubernetesBackend(get_conf())
+    elif backend_name == 'Swarm':
+        if SwarmBackend is None:
+            raise ZoeException('The Swarm backend requires docker python version >= 2.0.2')
+        return SwarmBackend(get_conf())
     else:
         log.error('Unknown backend selected')
         assert False
@@ -72,10 +94,12 @@ def service_list_to_containers(execution: Execution, service_list: List[Service]
     for service in ordered_service_list:
         env_subst_dict['dns_name#self'] = service.dns_name
         service.set_starting()
+        instance = ServiceInstance(execution, service, env_subst_dict)
         try:
-            backend.spawn_service(execution, service, env_subst_dict)
+            backend_id, ip_address = backend.spawn_service(instance)
         except ZoeStartExecutionRetryException as ex:
             log.warning('Temporary failure starting service {} of execution {}: {}'.format(service.id, execution.id, ex.message))
+            service.set_error(ex.message)
             execution.set_error_message(ex.message)
             terminate_execution(execution)
             execution.set_scheduled()
@@ -94,7 +118,8 @@ def service_list_to_containers(execution: Execution, service_list: List[Service]
             execution.set_error()
             return "fatal"
         else:
-            execution.set_running()
+            log.debug('Service {} started'.format(instance.name))
+            service.set_active(backend_id, ip_address)
 
     return "ok"
 

zoe_master/backends/kubernetes/backend.py

@@ -16,15 +16,11 @@
 """Zoe backend implementation for Kubernetes with docker."""
 
 import logging
-from typing import Dict
 
-from zoe_lib.config import get_conf
-from zoe_lib.exceptions import ZoeLibException, ZoeNotEnoughResourcesException
-from zoe_lib.state import Execution, Service
-from zoe_master.backends.kubernetes.api_client import DockerContainerOptions, KubernetesClient
-from zoe_master.exceptions import ZoeStartExecutionRetryException, ZoeStartExecutionFatalException, ZoeException
-from zoe_master.workspace.filesystem import ZoeFSWorkspace
-import zoe_master.backends.common
+from zoe_lib.state import Service
+from zoe_master.backends.kubernetes.api_client import KubernetesClient
+from zoe_master.exceptions import ZoeStartExecutionRetryException, ZoeStartExecutionFatalException, ZoeException, ZoeNotEnoughResourcesException
+from zoe_master.backends.service_instance import ServiceInstance
 import zoe_master.backends.base
 from zoe_master.backends.kubernetes.threads import KubernetesMonitor, KubernetesStateSynchronizer
 from zoe_master.stats import NodeStats, ClusterStats  # pylint: disable=unused-import
@@ -55,74 +51,17 @@ class KubernetesBackend(zoe_master.backends.base.BaseBackend):
         _monitor.quit()
         _checker.quit()
 
-    def spawn_service(self, execution: Execution, service: Service, env_subst_dict: Dict):
+    def spawn_service(self, service_instance: ServiceInstance):
         """Spawn a service, translating a Zoe Service into a Docker container."""
-        copts = DockerContainerOptions()
-        copts.gelf_log_address = get_conf().gelf_address
-        copts.name = service.dns_name
-        copts.set_memory_limit(service.resource_reservation.memory)
-        copts.set_cores_limit(service.resource_reservation.cores)
-        copts.network_name = get_conf().overlay_network_name
-        copts.labels = {
-            'zoe.execution.name': execution.name,
-            'zoe.execution.id': str(execution.id),
-            'zoe.service.name': service.name,
-            'zoe.service.id': str(service.id),
-            'zoe.owner': execution.user_id,
-            'zoe.deployment_name': get_conf().deployment_name,
-            'zoe.type': 'app_service'
-        }
-        if service.is_monitor:
-            copts.labels['kubernetes.monitor'] = 'true'
-        else:
-            copts.labels['kubernetes.monitor'] = 'false'
-
-        # Always disable autorestart
-        # if 'disable_autorestart' in execution.description and execution.description['disable_autorestart']:
-        #     log.debug("Autorestart disabled for service {}".format(service.id))
-        #     copts.restart = False
-        # else:
-        # copts.restart = not service.is_monitor  # Monitor containers should not restart
-        copts.restart = False
-
-        env_vars = zoe_master.backends.common.gen_environment(execution, service, env_subst_dict)
-        for name, value in env_vars:
-            copts.add_env_variable(name, value)
-
-        for port in service.ports:
-            if port.expose:
-                copts.ports.append(port.number)
-
-        for volume in service.volumes:
-            if volume.type == "host_directory":
-                copts.add_volume_bind(volume.path, volume.mount_point, volume.readonly)
-            else:
-                log.warning('Kubernetes backend does not support volume type {}'.format(volume.type))
-
-        # if 'constraints' in service.description:
-        #     for constraint in service.description['constraints']:
-        #         copts.add_constraint(constraint)
-
-        fswk = ZoeFSWorkspace()
-        if fswk.can_be_attached():
-            copts.add_volume_bind(fswk.get_path(execution.user_id), fswk.get_mountpoint(), False)
-            copts.add_env_variable('ZOE_WORKSPACE', fswk.get_mountpoint())
-
-        # The same dictionary is used for templates in the command
-        copts.set_command(service.command.format(**env_subst_dict))
-
-        copts.set_replicas(service.replicas)
-
         try:
-            self.kube.spawn_service(copts)
-            rc_info = self.kube.spawn_replication_controller(service.description['docker_image'], copts)
+            self.kube.spawn_service(service_instance)
+            rc_info = self.kube.spawn_replication_controller(service_instance)
         except ZoeNotEnoughResourcesException:
-            service.set_error('Not enough free resources to satisfy reservation request')
-            raise ZoeStartExecutionRetryException('Not enough free resources to satisfy reservation request for service {}'.format(service.name))
-        except (ZoeException, ZoeLibException) as e:
+            raise ZoeStartExecutionRetryException('Not enough free resources to satisfy reservation request for service {}'.format(service_instance.name))
+        except ZoeException as e:
             raise ZoeStartExecutionFatalException(str(e))
 
-        service.set_active(rc_info["backend_id"], rc_info['ip_address'])
+        return rc_info["backend_id"], rc_info['ip_address']
 
     def terminate_service(self, service: Service) -> None:
         """Terminate and delete a container."""

zoe_master/backends/kubernetes/threads.py

@@ -22,8 +22,10 @@ import time
 from zoe_lib.config import get_conf
 from zoe_lib.state import SQLManager, Service
 from zoe_master.backends.kubernetes.api_client import KubernetesClient
+
 log = logging.getLogger(__name__)
 
+
 class KubernetesMonitor(threading.Thread):
     """The monitor."""
 
@@ -40,7 +42,7 @@ class KubernetesMonitor(threading.Thread):
     def run(self):
         """An infinite loop that listens for events from Kubernetes."""
         log.info("Monitor thread started")
-        while True: # pylint: disable=too-many-nested-blocks
+        while True:  # pylint: disable=too-many-nested-blocks
             for event in self.kube.replication_controller_event():
                 log.debug('%s: %s', event.object.name, event.type)
                 if event.type != 'DELETED' and event.type != 'ADDED':
@@ -79,8 +81,10 @@ class KubernetesMonitor(threading.Thread):
         """Stops the thread."""
         self.stop = True
 
+
 CHECK_INTERVAL = 300
 
+
 class KubernetesStateSynchronizer(threading.Thread):
     """The Kubernetes Checker."""
 

zoe_master/backends/service_instance.py

+# Copyright (c) 2017, Daniele Venzano
+#
+# 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.
+
+"""When a service from the application description needs to be instantiated, it is transformed into a ServiceInstance, an internal representation of a generic container. This class is used to gather all the attributes that describe a container and to provide a clear interface with the backend."""
+
+from zoe_lib.state import Service, Execution
+from zoe_lib.config import get_conf
+import zoe_master.backends.common
+
+
+class ServiceInstance:
+    """The ServiceInstance class, a Service that is going to be instantiated into a container."""
+    def __init__(self, execution: Execution, service: Service, env_subst_dict):
+        self.name = service.unique_name
+        self.hostname = service.dns_name
+
+        self.memory_limit = service.resource_reservation.memory
+        self.core_limit = service.resource_reservation.cores
+
+        self.labels = {
+            'zoe.execution.name': execution.name,
+            'zoe.execution.id': str(execution.id),
+            'zoe.service.name': service.name,
+            'zoe.service.id': str(service.id),
+            'zoe.owner': execution.user_id,
+            'zoe.deployment_name': get_conf().deployment_name,
+            'zoe.type': 'app_service'
+        }
+        if service.is_monitor:
+            self.labels['zoe_monitor'] = 'true'
+        else:
+            self.labels['zoe_monitor'] = 'false'
+
+        self.labels = zoe_master.backends.common.gen_labels(service, execution)
+        self.environment = service.environment + zoe_master.backends.common.gen_environment(execution, service, env_subst_dict)
+        self.volumes = service.volumes + zoe_master.backends.common.gen_volumes(service, execution)
+
+        self.command = service.command
+
+        self.image_name = service.image_name
+
+        self.ports = service.ports
+
+        self.replicas_count = service.replicas

zoe_master/backends/swarm/api_client.py

+# Copyright (c) 2016, Daniele Venzano
+#
+# 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.
+
+"""Interface to the low-level Docker API."""
+
+import time
+import logging
+from typing import Iterable, Callable, Dict, Any
+
+import humanfriendly
+
+try:
+    from consul import Consul
+except ImportError:
+    Consul = None
+
+try:
+    from kazoo.client import KazooClient
+except ImportError:
+    KazooClient = None
+
+import docker
+import docker.tls
+import docker.errors
+import docker.utils
+import docker.models.containers
+
+import requests.packages
+
+from zoe_lib.config import get_conf
+from zoe_lib.state import Service
+from zoe_master.stats import ClusterStats, NodeStats
+from zoe_master.backends.service_instance import ServiceInstance
+from zoe_master.exceptions import ZoeException, ZoeNotEnoughResourcesException
+
+log = logging.getLogger(__name__)
+
+try:
+    docker.DockerClient()
+except AttributeError:
+    log.error('Docker package does not have the DockerClient attribute')
+    raise ImportError('Wrong Docker library version')
+
+
+def zookeeper_swarm(zk_server_list: str, path='/docker') -> str:
+    """
+    Given a Zookeeper server list, find the currently active Swarm master.
+    :param zk_server_list: Zookeeper server list
+    :param path: Swarm path in Zookeeper
+    :return: Swarm master connection string
+    """
+    path += '/docker/swarm/leader'
+    zk_client = KazooClient(hosts=zk_server_list)
+    zk_client.start()
+    master, stat_ = zk_client.get(path)
+    zk_client.stop()
+    return master.decode('utf-8')
+
+
+def consul_swarm(consul_ip: str) -> str:
+    """
+    Using consul as discovery service, find the currently active Swarm master.
+    :param consul_ip: consul ip address
+    :return: Swarm master connection string
+    """
+    leader_key = 'docker/swarm/leader'
+    consul_client = Consul(consul_ip)
+    key_val = consul_client.kv.get(leader_key)
+    master = key_val[1]['Value']
+    return master.decode('utf-8')
+
+
+class SwarmClient:
+    """The Swarm client class that wraps the Docker API."""
+    def __init__(self) -> None:
+        url = get_conf().backend_swarm_url
+        tls = False
+        if 'zk://' in url:
+            if KazooClient is None:
+                raise ZoeException('ZooKeeper URL for Swarm, but the kazoo package is not installed')
+            url = url[len('zk://'):]
+            manager = zookeeper_swarm(url, get_conf().backend_swarm_zk_path)
+        elif 'consul://' in url:
+            if Consul is None:
+                raise ZoeException('Consul URL for Swarm, but the consul package is not installed')
+            url = url[len('consul://'):]
+            manager = consul_swarm(url)
+        elif 'http://' in url:
+            manager = url
+        elif 'https://' in url:
+            tls = docker.tls.TLSConfig(client_cert=(get_conf().backend_swarm_tls_cert, get_conf().backend_swarm_tls_key), verify=get_conf().backend_swarm_tls_ca)
+            manager = url
+        else:
+            raise ZoeException('Unsupported URL scheme for Swarm')
+        self.cli = docker.DockerClient(base_url=manager, version="auto", tls=tls)
+
+    def info(self) -> ClusterStats:
+        """Retrieve Swarm statistics. The Docker API returns a mess difficult to parse."""
+        info = self.cli.info()
+        pl_status = ClusterStats()
+        pl_status.container_count = info["Containers"]
+        pl_status.memory_total = info["MemTotal"]
+        pl_status.cores_total = info["NCPU"]
+
+        # SystemStatus is a list...
+        idx = 0  # Role, skip
+        idx += 1
+        assert 'Strategy' in info["SystemStatus"][idx][0]
+        pl_status.placement_strategy = info["SystemStatus"][idx][1]
+        idx += 1
+        assert 'Filters' in info["SystemStatus"][idx][0]
+        pl_status.active_filters = [x.strip() for x in info["SystemStatus"][idx][1].split(", ")]
+        idx += 1
+        assert 'Nodes' in info["SystemStatus"][idx][0]
+        node_count = int(info["SystemStatus"][idx][1])
+        idx += 1  # At index 4 the nodes begin
+        for node in range(node_count):
+            idx2 = 0
+            node_stats = NodeStats(info["SystemStatus"][idx + node][0].strip())
+            node_stats.docker_endpoint = info["SystemStatus"][idx + node][1]
+            idx2 += 1  # ID, skip
+            idx2 += 1  # Status
+            node_stats.status = info["SystemStatus"][idx + node + idx2][1]
+            idx2 += 1  # Containers
+            node_stats.container_count = int(info["SystemStatus"][idx + node + idx2][1].split(' ')[0])
+            idx2 += 1  # CPUs
+            node_stats.cores_reserved = int(info["SystemStatus"][idx + node + idx2][1].split(' / ')[0])
+            node_stats.cores_total = int(info["SystemStatus"][idx + node + idx2][1].split(' / ')[1])
+            idx2 += 1  # Memory
+            node_stats.memory_reserved = info["SystemStatus"][idx + node + idx2][1].split(' / ')[0]
+            node_stats.memory_total = info["SystemStatus"][idx + node + idx2][1].split(' / ')[1]
+            idx2 += 1  # Labels
+            node_stats.labels = info["SystemStatus"][idx + node + idx2][1].split(', ')
+            idx2 += 1  # Last update
+            node_stats.last_update = info["SystemStatus"][idx + node + idx2][1]
+            idx2 += 1  # Docker version
+            node_stats.server_version = info["SystemStatus"][idx + node + idx2][1]
+
+            node_stats.memory_reserved = humanfriendly.parse_size(node_stats.memory_reserved)
+            node_stats.memory_total = humanfriendly.parse_size(node_stats.memory_total)
+
+            pl_status.nodes.append(node_stats)
+            idx += idx2
+        pl_status.timestamp = time.time()
+        return pl_status
+
+    def spawn_container(self, service_instance: ServiceInstance) -> Dict[str, Any]:
+        """Create and start a new container."""
+        cont = None
+        port_bindings = {}  # type: Dict[str, Any]
+        for port in service_instance.ports:
+            if port.expose:
+                port_bindings[str(port.number) + '/tcp'] = None
+
+        if get_conf().gelf_address != '':