[docker] Add support for setting CgroupnsMode

This is required to support Debian Bullseye (11) - need to set
nova-libvirt to use 'host' CgroupnsMode.

Change-Id: I40213d4092fa325bcf37bb1fb4437ab125fe328b

ansible/library/kolla_docker.py

@@ -27,6 +27,8 @@ import traceback
 
 import docker
 
+from distutils.version import StrictVersion
+
 from ansible.module_utils.basic import AnsibleModule
 
 DOCUMENTATION = '''
@@ -149,6 +151,16 @@ options:
     default: None
     choices:
       - host
+  cgroupns_mode:
+    description:
+      - Set docker cgroups namespace (default depends on Docker config)
+      - Supported only with Docker 20.10 (Docker API 1.41) and later
+    required: False
+    type: str
+    default: None
+    choices:
+      - private
+      - host
   privileged:
     description:
       - Set the container to privileged
@@ -275,6 +287,9 @@ class DockerWorker(object):
 
         self.dc = get_docker_client()(**options)
 
+        self._cgroupns_mode_supported = (
+            StrictVersion(self.dc._version) >= StrictVersion('1.41'))
+
     def generate_tls(self):
         tls = {'verify': self.params.get('tls_verify')}
         tls_cert = self.params.get('tls_cert'),
@@ -347,6 +362,7 @@ class DockerWorker(object):
             self.compare_labels(container_info) or
             self.compare_privileged(container_info) or
             self.compare_pid_mode(container_info) or
+            self.compare_cgroupns_mode(container_info) or
             self.compare_tmpfs(container_info) or
             self.compare_volumes(container_info) or
             self.compare_volumes_from(container_info) or
@@ -402,6 +418,21 @@ class DockerWorker(object):
         if new_pid_mode != current_pid_mode:
             return True
 
+    def compare_cgroupns_mode(self, container_info):
+        if not self._cgroupns_mode_supported:
+            return False
+        new_cgroupns_mode = self.params.get('cgroupns_mode')
+        if new_cgroupns_mode is None:
+            # means we don't care what it is
+            return False
+        current_cgroupns_mode = (container_info['HostConfig']
+                                 .get('CgroupnsMode'))
+        if current_cgroupns_mode == '':
+            # means the container was created on Docker pre-20.10
+            # it behaves like 'host'
+            current_cgroupns_mode = 'host'
+        return new_cgroupns_mode != current_cgroupns_mode
+
     def compare_privileged(self, container_info):
         new_privileged = self.params.get('privileged')
         current_privileged = container_info['HostConfig']['Privileged']
@@ -760,7 +791,16 @@ class DockerWorker(object):
         if binds:
             options['binds'] = binds
 
-        return self.dc.create_host_config(**options)
+        host_config = self.dc.create_host_config(**options)
+
+        if self._cgroupns_mode_supported:
+            # NOTE(yoctozepto): python-docker does not support CgroupnsMode
+            # natively so we stuff it in manually.
+            cgroupns_mode = self.params.get('cgroupns_mode')
+            if cgroupns_mode is not None:
+                host_config['CgroupnsMode'] = cgroupns_mode
+
+        return host_config
 
     def _inject_env_var(self, environment_info):
         newenv = {
@@ -1074,6 +1114,8 @@ def generate_module():
         cap_add=dict(required=False, type='list', default=list()),
         security_opt=dict(required=False, type='list', default=list()),
         pid_mode=dict(required=False, type='str', choices=['host', '']),
+        cgroupns_mode=dict(required=False, type='str',
+                           choices=['private', 'host']),
         privileged=dict(required=False, type='bool', default=False),
         graceful_timeout=dict(required=False, type='int', default=10),
         remove_on_exit=dict(required=False, type='bool', default=True),

releasenotes/notes/docker-cgroupns-mode-9e1b32c357a14095.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Adds support in ``kolla_docker`` module to set ``CgroupnsMode`` for Docker
+    containers (via ``cgroupns_mode`` module param). Requires Docker 20.10.
+    Note that pre-20.10 all containers behave as if they were run with mode
+    ``host``.

tests/test_kolla_docker.py

@@ -71,6 +71,8 @@ class ModuleArgsTest(base.BaseTestCase):
             cap_add=dict(required=False, type='list', default=list()),
             security_opt=dict(required=False, type='list', default=list()),
             pid_mode=dict(required=False, type='str', choices=['host', '']),
+            cgroupns_mode=dict(required=False, type='str',
+                               choices=['private', 'host']),
             privileged=dict(required=False, type='bool', default=False),
             graceful_timeout=dict(required=False, type='int', default=10),
             remove_on_exit=dict(required=False, type='bool', default=True),
@@ -204,10 +206,11 @@ FAKE_DATA = {
 }
 
 
-@mock.patch("docker.APIClient")
-def get_DockerWorker(mod_param, mock_dclient):
+def get_DockerWorker(mod_param, docker_api_version='1.40'):
     module = mock.MagicMock()
     module.params = mod_param
+    with mock.patch("docker.APIClient") as MockedDockerClientClass:
+        MockedDockerClientClass.return_value._version = docker_api_version
         dw = kd.DockerWorker(module)
         return dw
 
@@ -248,6 +251,15 @@ class TestMainModule(base.BaseTestCase):
                                                       result=False,
                                                       some_key="some_value")
 
+    def test_sets_cgroupns_mode_supported_false(self):
+        self.dw = get_DockerWorker(self.fake_data['params'])
+        self.assertFalse(self.dw._cgroupns_mode_supported)
+
+    def test_sets_cgroupns_mode_supported_true(self):
+        self.dw = get_DockerWorker(self.fake_data['params'],
+                                   docker_api_version='1.41')
+        self.assertTrue(self.dw._cgroupns_mode_supported)
+
 
 class TestContainer(base.BaseTestCase):
 
@@ -976,6 +988,40 @@ class TestAttrComp(base.BaseTestCase):
         self.dw = get_DockerWorker({'pid_mode': 'host2'})
         self.assertTrue(self.dw.compare_pid_mode(container_info))
 
+    def test_compare_cgroupns_mode_neg(self):
+        container_info = {'HostConfig': dict(CgroupnsMode='host')}
+        self.dw = get_DockerWorker({'cgroupns_mode': 'host'},
+                                   docker_api_version='1.41')
+        self.assertFalse(self.dw.compare_cgroupns_mode(container_info))
+
+    def test_compare_cgroupns_mode_neg_backward_compat(self):
+        container_info = {'HostConfig': dict(CgroupnsMode='')}
+        self.dw = get_DockerWorker({'cgroupns_mode': 'host'},
+                                   docker_api_version='1.41')
+        self.assertFalse(self.dw.compare_cgroupns_mode(container_info))
+
+    def test_compare_cgroupns_mode_ignore(self):
+        container_info = {'HostConfig': dict(CgroupnsMode='private')}
+        self.dw = get_DockerWorker({}, docker_api_version='1.41')
+        self.assertFalse(self.dw.compare_cgroupns_mode(container_info))
+
+    def test_compare_cgroupns_mode_pos(self):
+        container_info = {'HostConfig': dict(CgroupnsMode='private')}
+        self.dw = get_DockerWorker({'cgroupns_mode': 'host'},
+                                   docker_api_version='1.41')
+        self.assertTrue(self.dw.compare_cgroupns_mode(container_info))
+
+    def test_compare_cgroupns_mode_pos_backward_compat(self):
+        container_info = {'HostConfig': dict(CgroupnsMode='')}
+        self.dw = get_DockerWorker({'cgroupns_mode': 'private'},
+                                   docker_api_version='1.41')
+        self.assertTrue(self.dw.compare_cgroupns_mode(container_info))
+
+    def test_compare_cgroupns_mode_unsupported(self):
+        container_info = {'HostConfig': dict()}
+        self.dw = get_DockerWorker({'cgroupns_mode': 'host'})
+        self.assertFalse(self.dw.compare_cgroupns_mode(container_info))
+
     def test_compare_privileged_neg(self):
         container_info = {'HostConfig': dict(Privileged=True)}
         self.dw = get_DockerWorker({'privileged': True})