Port replicatedservice template to chart format

examples/charts/replicatedservice/Chart.yaml

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+name: replicatedservice
+description: Port of the replicatedservice template from kubernetes/charts
+version: 3
+expander:
+  name: Expandybird
+  entrypoint: templates/replicatedservice.py
+schema: templates/replicatedservice.py.schema

examples/charts/replicatedservice/templates/replicatedservice.py

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+"""Defines a ReplicatedService type by creating both a Service and an RC.
+
+This module creates a typical abstraction for running a service in a
+Kubernetes cluster, namely a replication controller and a service packaged
+together into a single unit.
+"""
+
+import yaml
+
+SERVICE_TYPE_COLLECTION = 'Service'
+RC_TYPE_COLLECTION = 'ReplicationController'
+
+
+def GenerateConfig(context):
+  """Generates a Replication Controller and a matching Service.
+
+  Args:
+    context: Template context. See schema for context properties
+
+  Returns:
+    A Container Manifest as a YAML string.
+  """
+  # YAML config that we're going to create for both RC & Service
+  config = {'resources': []}
+
+  name = context.env['name']
+  container_name = context.properties.get('container_name', name)
+  namespace = context.properties.get('namespace', 'default')
+
+  # Define things that the Service cares about
+  service_name = context.properties.get('service_name', name + '-service')
+  service_type = SERVICE_TYPE_COLLECTION
+
+  # Define things that the Replication Controller (rc) cares about
+  rc_name = context.properties.get('rc_name', name + '-rc')
+  rc_type = RC_TYPE_COLLECTION
+
+  service = {
+      'name': service_name,
+      'type': service_type,
+      'properties': {
+          'apiVersion': 'v1',
+          'kind': 'Service',
+          'namespace': namespace,
+          'metadata': {
+              'name': service_name,
+              'labels': GenerateLabels(context, service_name),
+          },
+          'spec': {
+              'ports': [GenerateServicePorts(context, container_name)],
+              'selector': GenerateLabels(context, name)
+          }
+      }
+  }
+  set_up_external_lb = context.properties.get('external_service', None)
+  if set_up_external_lb:
+    service['properties']['spec']['type'] = 'LoadBalancer'
+  cluster_ip = context.properties.get('cluster_ip', None)
+  if cluster_ip:
+    service['properties']['spec']['clusterIP'] = cluster_ip
+  config['resources'].append(service)
+
+  rc = {
+      'name': rc_name,
+      'type': rc_type,
+      'properties': {
+          'apiVersion': 'v1',
+          'kind': 'ReplicationController',
+          'namespace': namespace,
+          'metadata': {
+              'name': rc_name,
+              'labels': GenerateLabels(context, rc_name),
+          },
+          'spec': {
+              'replicas': context.properties['replicas'],
+              'selector': GenerateLabels(context, name),
+              'template': {
+                  'metadata': {
+                      'labels': GenerateLabels(context, name),
+                  },
+                  'spec': {
+                      'containers': [
+                          {
+                              'env': GenerateEnv(context),
+                              'name': container_name,
+                              'image': context.properties['image'],
+                              'ports': [
+                                  {
+                                      'name': container_name,
+                                      'containerPort': context.properties['container_port'],
+                                  }
+                              ],
+                          }
+                      ],
+                  }
+              }
+          }
+      }
+  }
+
+  # Set up volume mounts
+  if context.properties.get('volumes', None):
+    rc['properties']['spec']['template']['spec']['containers'][0]['volumeMounts'] = []
+    rc['properties']['spec']['template']['spec']['volumes'] = []
+    for volume in context.properties['volumes']:
+      # mountPath should be unique
+      volume_name = volume['mount_path'].replace('/', '-').lstrip('-') + '-storage'
+      rc['properties']['spec']['template']['spec']['containers'][0]['volumeMounts'].append(
+          {
+              'name': volume_name,
+              'mountPath': volume['mount_path']
+          }
+      )
+      del volume['mount_path']
+      volume['name'] = volume_name
+      rc['properties']['spec']['template']['spec']['volumes'].append(volume)
+
+  if context.properties.get('privileged', False):
+    rc['properties']['spec']['template']['spec']['containers'][0]['securityContext'] = {
+        'privileged': True
+    }
+
+  config['resources'].append(rc)
+  return yaml.dump(config)
+
+
+# Generates labels either from the context.properties['labels'] or generates
+# a default label 'name':name
+def GenerateLabels(context, name):
+  """Generates labels from context.properties['labels'] or creates default.
+
+  We make a deep copy of the context.properties['labels'] section to avoid
+  linking in the yaml document, which I believe reduces readability of the
+  expanded template. If no labels are given, generate a default 'name':name.
+
+  Args:
+    context: Template context, which can contain the following properties:
+             labels - Labels to generate
+
+  Returns:
+    A dict containing labels in a name:value format
+  """
+  tmp_labels = context.properties.get('labels', None)
+  ret_labels = {'name': name}
+  if isinstance(tmp_labels, dict):
+    for key, value in tmp_labels.iteritems():
+      ret_labels[key] = value
+  return ret_labels
+
+
+def GenerateServicePorts(context, name):
+  """Generates a ports section for a service.
+
+  Args:
+    context: Template context, which can contain the following properties:
+             service_port - Port to use for the service
+             target_port - Target port for the service
+             protocol - Protocol to use.
+
+  Returns:
+    A dict containing a port definition
+  """
+  container_port = context.properties['container_port']
+  target_port = context.properties.get('target_port', container_port)
+  service_port = context.properties.get('service_port', target_port)
+  protocol = context.properties.get('protocol')
+
+  ports = {}
+  if name:
+    ports['name'] = name
+  if service_port:
+    ports['port'] = service_port
+  if target_port:
+    ports['targetPort'] = target_port
+  if protocol:
+    ports['protocol'] = protocol
+
+  return ports
+
+def GenerateEnv(context):
+  """Generates environmental variables for a pod.
+
+  Args:
+    context: Template context, which can contain the following properties:
+             env - Environment variables to set.
+
+  Returns:
+    A list containing env variables in dict format {name: 'name', value: 'value'}
+  """
+  env = []
+  tmp_env = context.properties.get('env', [])
+  for entry in tmp_env:
+    if isinstance(entry, dict):
+      env.append({'name': entry.get('name'), 'value': entry.get('value')})
+  return env

examples/charts/replicatedservice/templates/replicatedservice.py.schema

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+info:
+  title: Replicated Service
+  description: |
+    Defines a ReplicatedService type by creating both a Service and an RC.
+
+    This module creates a typical abstraction for running a service in a
+    Kubernetes cluster, namely a replication controller and a service packaged
+    together into a single unit.
+
+required:
+- image
+
+properties:
+  container_name:
+    type: string
+    description: Name to use for container. If omitted, name is used.
+  service_name:
+    type: string
+    description: Name to use for service. If omitted, name-service is used.
+  namespace:
+    type: string
+    description: Namespace to create resources in. If omitted, 'default' is
+      used.
+    default: default
+  protocol:
+    type: string
+    description: Protocol to use for the service.
+  service_port:
+    type: int
+    description: Port to use for the service.
+  target_port:
+    type: int
+    description: Target port to use for the service.
+  container_port:
+    type: int
+    description: Port to use for the container.
+  replicas:
+    type: int
+    description: Number of replicas to create in RC.
+  image:
+    type: string
+    description: Docker image to use for replicas.
+  labels:
+    type: object
+    description: Labels to apply.
+  env:
+    type: array
+    description: Environment variables to apply.
+    properties:
+      name:
+        type: string
+      value:
+        type: string
+  external_service:
+    type: boolean
+    description: If set to true, enable external load balancer.
+  cluster_ip:
+    type: string
+    description: IP to use for the service
+  privileged:
+    type: boolean
+    description: If set to true, enable privileged container
+  volumes:
+    type: array
+    description: Volumes to mount.
+    items:
+      type: object
+      properties:
+        mounth_path:
+          type: string
+          description: Path to mount volume
+        # See https://cloud.google.com/container-engine/docs/spec-schema?hl=en for possible volumes. Since we only use gcePersistentDisk and NFS in our examples we have only added these ones.
+        oneOf:
+          gcePersistentDisk:
+            pdName:
+              type: string
+              description: Persistent's disk name
+            fsType:
+              type: string
+              description: Filesystem type of the persistent disk
+          nfs:
+            server:
+              type: string
+              description: The hostname or IP address of the NFS server
+            path:
+              type: string
+              description: The path that is exported by the NFS server
+            readOnly:
+              type: boolean
+              description: Forces the NFS export to be mounted with read-only permissions
+