diff options
Diffstat (limited to 'k8s/k8sclient/k8sclient.py')
| -rw-r--r-- | k8s/k8sclient/k8sclient.py | 104 |
1 files changed, 77 insertions, 27 deletions
diff --git a/k8s/k8sclient/k8sclient.py b/k8s/k8sclient/k8sclient.py index 7ca7b03..c4ba67d 100644 --- a/k8s/k8sclient/k8sclient.py +++ b/k8s/k8sclient/k8sclient.py @@ -64,7 +64,7 @@ def _create_probe(hc, port): probe = None period = hc.get('interval', PROBE_DEFAULT_PERIOD) timeout = hc.get('timeout', PROBE_DEFAULT_TIMEOUT) - if probe_type == 'http' or probe_type == 'https': + if probe_type in ['http', 'https']: probe = client.V1Probe( failure_threshold = 1, initial_delay_seconds = 5, @@ -74,9 +74,9 @@ def _create_probe(hc, port): path = hc['endpoint'], port = port, scheme = probe_type.upper() - ) + ) ) - elif probe_type == 'script' or probe_type == 'docker': + elif probe_type in ['script', 'docker']: probe = client.V1Probe( failure_threshold = 1, initial_delay_seconds = 5, @@ -84,9 +84,9 @@ def _create_probe(hc, port): timeout_seconds = timeout, _exec = client.V1ExecAction( command = [hc['script']] - ) + ) ) - return probe + return probe def _create_container_object(name, image, always_pull, env={}, container_ports=[], volume_mounts = [], readiness = None): # Set up environment variables @@ -99,8 +99,8 @@ def _create_container_object(name, image, always_pull, env={}, container_ports=[ # If a health check is specified, create a readiness probe # (For an HTTP-based check, we assume it's at the first container port) probe = None - - if (readiness): + + if readiness: hc_port = None if len(container_ports) > 0: hc_port = container_ports[0] @@ -121,7 +121,7 @@ def _create_deployment_object(component_name, containers, replicas, volumes, - labels, + labels, pull_secrets=[]): # pull_secrets is a list of the names of the k8s secrets containing docker registry credentials @@ -144,14 +144,14 @@ def _create_deployment_object(component_name, replicas=replicas, template=template ) - + # Create deployment object deployment = client.ExtensionsV1beta1Deployment( kind="Deployment", metadata=client.V1ObjectMeta(name=_create_deployment_name(component_name)), spec=spec ) - + return deployment def _create_service_object(service_name, component_name, service_ports, annotations, labels, service_type): @@ -185,7 +185,7 @@ def _parse_ports(port_list): port_map[container] = hport except: pass # if something doesn't parse, we just ignore it - + return container_ports, port_map def _parse_volumes(volume_list): @@ -198,7 +198,7 @@ def _parse_volumes(volume_list): vro = (v['container']['mode'] == 'ro') volumes.append(client.V1Volume(name=vname, host_path=client.V1HostPathVolumeSource(path=vhost))) volume_mounts.append(client.V1VolumeMount(name=vname, mount_path=vcontainer, read_only=vro)) - + return volumes, volume_mounts def _service_exists(namespace, component_name): @@ -209,9 +209,26 @@ def _service_exists(namespace, component_name): exists = True except client.rest.ApiException: pass - + return exists +def _patch_deployment(namespace, deployment, modify): + ''' + Gets the current spec for 'deployment' in 'namespace', + uses the 'modify' function to change the spec, + then sends the updated spec to k8s. + ''' + _configure_api() + + # Get deployment spec + spec = client.ExtensionsV1beta1Api().read_namespaced_deployment(deployment, namespace) + + # Apply changes to spec + spec = modify(spec) + + # Patch the deploy with updated spec + client.ExtensionsV1beta1Api().patch_namespaced_deployment(deployment, namespace, spec) + def deploy(namespace, component_name, image, replicas, always_pull, k8sconfig, **kwargs): ''' This will create a k8s Deployment and, if needed, one or two k8s Services. @@ -219,7 +236,7 @@ def deploy(namespace, component_name, image, replicas, always_pull, k8sconfig, * We're not exposing k8s to the component developer and the blueprint author. This is a conscious choice. We want to use k8s in a controlled, consistent way, and we want to hide the details from the component developer and the blueprint author.) - + namespace: the Kubernetes namespace into which the component is deployed component_name: the component name, used to derive names of Kubernetes entities image: the docker image for the component being deployed @@ -359,11 +376,10 @@ def deploy(namespace, component_name, image, replicas, always_pull, k8sconfig, * return dep, deployment_description def undeploy(deployment_description): - # TODO: do real configuration _configure_api() namespace = deployment_description["namespace"] - + # remove any services associated with the component for service in deployment_description["services"]: client.CoreV1Api().delete_namespaced_service(service, namespace) @@ -375,20 +391,54 @@ def undeploy(deployment_description): def is_available(namespace, component_name): _configure_api() dep_status = client.AppsV1beta1Api().read_namespaced_deployment_status(_create_deployment_name(component_name), namespace) - # Check if the number of available replicas is equal to the number requested - return dep_status.status.available_replicas >= dep_status.spec.replicas + # Check if the number of available replicas is equal to the number requested and that the replicas match the current spec + # This check can be used to verify completion of an initial deployment, a scale operation, or an update operation + return dep_status.status.available_replicas == dep_status.spec.replicas and dep_status.status.updated_replicas == dep_status.spec.replicas def scale(deployment_description, replicas): - # TODO: do real configuration - _configure_api() + ''' Trigger a scaling operation by updating the replica count for the Deployment ''' - namespace = deployment_description["namespace"] - name = deployment_description["deployment"] + def update_replica_count(spec): + spec.spec.replicas = replicas + return spec - # Get deployment spec - spec = client.ExtensionsV1beta1Api().read_namespaced_deployment(name, namespace) + _patch_deployment(deployment_description["namespace"], deployment_description["deployment"], update_replica_count) + +def upgrade(deployment_description, image, container_index = 0): + ''' Trigger a rolling upgrade by sending a new image name/tag to k8s ''' + + def update_image(spec): + spec.spec.template.spec.containers[container_index].image = image + return spec + + _patch_deployment(deployment_description["namespace"], deployment_description["deployment"], update_image) + +def rollback(deployment_description, rollback_to=0): + ''' + Undo upgrade by rolling back to a previous revision of the deployment. + By default, go back one revision. + rollback_to can be used to supply a specific revision number. + Returns the image for the app container and the replica count from the rolled-back deployment + ''' + ''' + 2018-07-13 + Currently this does not work due to a bug in the create_namespaced_deployment_rollback() method. + The k8s python client code throws an exception while processing the response from the API. + See: + - https://github.com/kubernetes-client/python/issues/491 + - https://github.com/kubernetes/kubernetes/pull/63837 + The fix has been merged into the master branch but is not in the latest release. + ''' + _configure_api() + deployment = deployment_description["deployment"] + namespace = deployment_description["namespace"] - # Update the replica count in the spec - spec.spec.replicas = replicas - client.ExtensionsV1beta1Api().patch_namespaced_deployment(name, namespace, spec) + # Initiate the rollback + client.ExtensionsV1beta1Api().create_namespaced_deployment_rollback( + deployment, + namespace, + client.AppsV1beta1DeploymentRollback(name=deployment, rollback_to=client.AppsV1beta1RollbackConfig(revision=rollback_to))) + # Read back the spec for the rolled-back deployment + spec = client.ExtensionsV1beta1Api().read_namespaced_deployment(deployment, namespace) + return spec.spec.template.spec.containers[0].image, spec.spec.replicas
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