Creating an HTTP load-balanced logbook app

This advanced example demonstrates how to build a logbook app that uses node.js for its frontend and MySQL for its backend. The template also creates and connects an HTTP load balancer that load balances across two zones, and an autoscaler to automatically scale the app.

This example assumes you are familiar with Docker containers, as well as Compute Engine resources, particularly HTTP load balancing, autoscaling, managed instance groups, and instance templates.

For more introductory tutorials, refer to the Getting started guide or the Step-by-step guide.

Before you begin

• If you want to use the command-line examples in this guide, install the `gcloud` command-line tool.
• If you want to use the API examples in this guide, set up API access.
• Familiar with Compute Engine HTTP load balancing.
• Familiar with Docker containers.

Creating your templates

This example launches a deployment with several types of resources. To start, you will create reusable templates that define these resources separately. Later on, you will use these templates in your final configuration.

At the end of this example, you will have a deployment that contains these resources:

• A single Compute Engine instance for the backend MySQL virtual machine.
• An instance template that uses a Docker image.
• Two autoscaled managed instance groups in two different zones, running the frontend node.js service.
• Another two autoscaled managed instance group serving static data.
• A health check and a HTTP load balancer to distributed traffic across the respective managed instance groups.

Creating the backend templates

The backend of this app is a single Compute Engine instance running a MySQL Docker container. Create a template that defines a Compute Engine instance that uses a container-optimized image. Name the file container_vm.[py|jinja]:

 {% from 'container_helper.jinja' import GenerateManifest %} {% set COMPUTE_URL_BASE = 'https://www.googleapis.com/compute/v1/' %} resources: - name: {{ env['name'] }}  type: compute.v1.instance  properties:  zone: {{ properties['zone'] }}  machineType: {{ COMPUTE_URL_BASE }}projects/{{ env['project'] }}/zones/{{ properties['zone'] }}/machineTypes/f1-micro  metadata:  items:  - key: gce-container-declaration  value: |  {{ GenerateManifest(env['name'], properties['port'], properties['dockerImage'], properties['dockerEnv'])|indent(10) }}  disks:  - deviceName: boot  type: PERSISTENT  autoDelete: true  boot: true  initializeParams:  diskName: {{ env['name'] }}-disk  sourceImage: {{ COMPUTE_URL_BASE }}projects/cos-cloud/global/images/{{ properties['containerImage'] }}  networkInterfaces:  - accessConfigs:  - name: external-nat  type: ONE_TO_ONE_NAT  network: {{ COMPUTE_URL_BASE }}projects/{{ env['project'] }}/global/networks/default  serviceAccounts:  - email: default  scopes:  - https://www.googleapis.com/auth/logging.write  - https://www.googleapis.com/auth/monitoring.write 

# Copyright 2016 Google Inc. All rights reserved. # # 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. """Creates a Container VM with the provided Container manifest.""" from container_helper import GenerateManifest COMPUTE_URL_BASE = 'https://www.googleapis.com/compute/v1/' def GlobalComputeUrl(project, collection, name): return ''.join([COMPUTE_URL_BASE, 'projects/', project, '/global/', collection, '/', name]) def ZonalComputeUrl(project, zone, collection, name): return ''.join([COMPUTE_URL_BASE, 'projects/', project, '/zones/', zone, '/', collection, '/', name]) def GenerateConfig(context):  """Generate configuration.""" base_name = context.env['name'] # Properties for the container-based instance. instance = { 'zone': context.properties['zone'], 'machineType': ZonalComputeUrl(context.env['project'], context.properties['zone'], 'machineTypes', 'f1-micro'), 'metadata': { 'items': [{ 'key': 'gce-container-declaration', 'value': GenerateManifest(context) }] }, 'disks': [{ 'deviceName': 'boot', 'type': 'PERSISTENT', 'autoDelete': True, 'boot': True, 'initializeParams': { 'diskName': base_name + '-disk', 'sourceImage': GlobalComputeUrl('cos-cloud', 'images', context.properties[ 'containerImage']) }, }], 'networkInterfaces': [{ 'accessConfigs': [{ 'name': 'external-nat', 'type': 'ONE_TO_ONE_NAT' }], 'network': GlobalComputeUrl(context.env['project'], 'networks', 'default') }], 'serviceAccounts': [{ 'email': 'default', 'scopes': ['https://www.googleapis.com/auth/logging.write'] }] } # Resources to return. resources = { 'resources': [{ 'name': base_name, 'type': 'compute.v1.instance', 'properties': instance }] } return resources 

The template defines a number of variables, such as the containerImage and the manifest, which will be filled in when you define your configuration. This template alone just creates a single virtual machine (VM) instance.

When you use container images on Compute Engine instances, you also need to provide a manifest file (different from a Deployment Manager manifest) to describe to Compute Engine which container image to use. Create a helper method called container_helper.[py|jinja] to dynamically define the container manifest:

 {% macro GenerateManifest(name, port, dockerImage, dockerEnv) -%}  apiVersion: v1 kind: Pod metadata:  name: {{ name }} spec:  containers:  - name: {{ name }}  image: {{ dockerImage }}  ports:  - hostPort: {{ port }}  containerPort: {{ port }}  {% if dockerEnv -%}  env:  {% for key, value in dockerEnv.items() -%}  - name: {{ key }}  value: '{{ value }}'  {% endfor -%}  {% endif -%} {%- endmacro -%} 

# Copyright 2016 Google Inc. All rights reserved. # # 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. """Helper methods for working with containers in config.""" import six import yaml def GenerateManifest(context):  """Generates a Container Manifest given a Template context.  Args:  context: Template context, which must contain dockerImage and port  properties, and an optional dockerEnv property.  Returns:  A Container Manifest as a YAML string.  """ env_list = [] if 'dockerEnv' in context.properties: for key, value in six.iteritems(context.properties['dockerEnv']): env_list.append({'name': key, 'value': str(value)}) manifest = { 'apiVersion': 'v1', 'kind': 'Pod', 'metadata': { 'name': str(context.env['name']) }, 'spec': { 'containers': [{ 'name': str(context.env['name']), 'image': context.properties['dockerImage'], 'ports': [{ 'hostPort': context.properties['port'], 'containerPort': context.properties['port'] }], }] } } if env_list: manifest['spec']['containers'][0]['env'] = env_list return yaml.dump(manifest, default_flow_style=False) 

Creating the frontend templates

The frontend of this app runs Node.js and allow users to post messages to the web page. There will be two managed instance groups that contain two instances each: a primary managed instance group, and a secondary managed instance group for load balancing.

To create these frontend templates, use the following instructions.

1. Create an instance template.

   You need an Instance Template resource to create a managed instance group, which is a group of identical VM instances that are centrally managed. This example creates a managed instance group for the frontend node.js instances, but first, you must create the Instance Template.

   Define a file named container_instance_template.[py|jinja]:

   Jinja

    {% from 'container_helper.jinja' import GenerateManifest %} {% set IT_NAME = env['name'] + '-it' %} resources: - name: {{ IT_NAME }}  type: compute.v1.instanceTemplate  properties:  properties:  metadata:  items:  - key: gce-container-declaration  value: |  {{ GenerateManifest(env['name'], properties['port'],properties['dockerImage'], properties['dockerEnv'])|indent(12) }}  machineType: f1-micro  disks:  - deviceName: boot  boot: true  autoDelete: true  mode: READ_WRITE  type: PERSISTENT  initializeParams:  sourceImage: https://www.googleapis.com/compute/v1/projects/cos-cloud/global/images/{{ properties['containerImage'] }}  networkInterfaces:  - accessConfigs:  - name: external-nat  type: ONE_TO_ONE_NAT  network: https://www.googleapis.com/compute/v1/projects/{{ env['project'] }}/global/networks/default  serviceAccounts:  - email: default  scopes:  - https://www.googleapis.com/auth/logging.write  - https://www.googleapis.com/auth/monitoring.write outputs: - name: instanceTemplateSelfLink  value: $(ref.{{ IT_NAME }}.selfLink) 

   Python

   # Copyright 2016 Google Inc. All rights reserved. # # 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. """Creates a Container VM with the provided Container manifest.""" from container_helper import GenerateManifest def GenerateConfig(context):  """Generates configuration.""" image = ''.join(['https://www.googleapis.com/compute/v1/', 'projects/cos-cloud/global/images/', context.properties['containerImage']]) default_network = ''.join(['https://www.googleapis.com/compute/v1/projects/', context.env['project'], '/global/networks/default']) instance_template = { 'name': context.env['name'] + '-it', 'type': 'compute.v1.instanceTemplate', 'properties': { 'properties': { 'metadata': { 'items': [{ 'key': 'gce-container-declaration', 'value': GenerateManifest(context) }] }, 'machineType': 'f1-micro', 'disks': [{ 'deviceName': 'boot', 'boot': True, 'autoDelete': True, 'mode': 'READ_WRITE', 'type': 'PERSISTENT', 'initializeParams': {'sourceImage': image} }], 'networkInterfaces': [{ 'accessConfigs': [{ 'name': 'external-nat', 'type': 'ONE_TO_ONE_NAT' }], 'network': default_network }], 'serviceAccounts': [{ 'email': 'default', 'scopes': ['https://www.googleapis.com/auth/logging.write'] }] } } } outputs = [{'name': 'instanceTemplateSelfLink', 'value': '$(ref.' + instance_template['name'] + '.selfLink)'}] return {'resources': [instance_template], 'outputs': outputs} 

2. Create an autoscaled managed instance group.

   Now that you have an instance template, you can define a template that uses the instance template to create an autoscaled managed instance group. Create a new file named autoscaled_group.[py|jinja] with the following contents:

   Jinja

    resources:  - name: {{ env["name"] }}-igm  type: compute.v1.instanceGroupManager  properties:  zone: {{ properties["zone"] }}  targetSize: {{ properties["size"] }}  baseInstanceName: {{ env["name"] }}-instance  instanceTemplate: {{ properties["instanceTemplate"] }}  - name: {{ env["name"] }}-as  type: compute.v1.autoscaler  properties:  zone: {{ properties["zone"] }}  target: $(ref.{{ env["name"] }}-igm.selfLink)  autoscalingPolicy:  maxNumReplicas: {{ properties["maxSize"] }} 

   Python

   # Copyright 2016 Google Inc. All rights reserved. # # 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. """Creates autoscaled, network LB IGM running specified docker image.""" def GenerateConfig(context):  """Generate YAML resource configuration.""" # NOTE: Once we can specify the port/service during creation of IGM, # we will wire it up here. name = context.env['name'] resources = [{ 'name': name + '-igm', 'type': 'compute.v1.instanceGroupManager', 'properties': { 'zone': context.properties['zone'], 'targetSize': context.properties['size'], 'baseInstanceName': name + '-instance', 'instanceTemplate': context.properties['instanceTemplate'] } }, { 'name': name + '-as', 'type': 'compute.v1.autoscaler', 'properties': { 'zone': context.properties['zone'], 'target': '$(ref.' + name + '-igm.selfLink)', 'autoscalingPolicy': { 'maxNumReplicas': context.properties['maxSize'] } } }] return {'resources': resources} 

   Create the corresponding schema file:

   Jinja

   # Copyright 2016 Google Inc. All rights reserved. # # 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. info:  title: Autoscaled, network LB IGM template  author: Google  description: Creates an autoscaled Instance Group Manager running the specified Docker image  version: 1.0 required: - zone - instanceTemplate properties:  zone:  type: string  description: Zone in which this VM will run  instanceTemplate:  type: string  description: URL for the instance template to use for IGM  size:  type: integer  default: 1  description: Initial size of the Managed Instance Group  maxSize:  type: integer  default: 1  description: Maximum size the Managed Instance Group will be autoscaled to 

   Python

   # Copyright 2016 Google Inc. All rights reserved. # # 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. info: title: Autoscaled, network LB IGM template author: Google description: Creates an autoscaled Instance Group Manager running the specified Docker image version: 1.0 required: - zone - instanceTemplate properties: zone: type: string description: Zone in which this VM will run instanceTemplate: type: string description: URL for the instance template to use for IGM size: type: integer default: 1 description: Initial size of the Managed Instance Group maxSize: type: integer default: 1 description: Maximum size the Managed Instance Group will be autoscaled to 

3. Create resources using these templates.

   Up to this point, you defined base templates that determine the properties of your resources. Using these templates, define the setup of your frontend. Create a new file named service.[py|jinja] with the following contents:

   Jinja

    resources:  - name: {{ env["name"] }}  type: container_instance_template.jinja  properties:  port: {{ properties["port"] }}  dockerEnv: {{ properties["dockerEnv"] }}  dockerImage: {{ properties["dockerImage"] }}  containerImage: {{ properties["containerImage"] }}  - name: {{ env["name"] }}-pri  type: autoscaled_group.jinja  properties:  zone: {{ properties["primaryZone"] }}  size: {{ properties["primarySize"] }}  maxSize: {{ properties["maxSize"] }}  port: {{ properties["port"] }}  service: {{ properties["service"] }}  baseInstanceName: {{ env["name"] }}-instance  instanceTemplate: $(ref.{{ env["name"] }}-it.selfLink)  - name: {{ env["name"] }}-sec  type: autoscaled_group.jinja  properties:  zone: {{ properties["secondaryZone"] }}  size: {{ properties["secondarySize"] }}  maxSize: {{ properties["maxSize"] }}  port: {{ properties["port"] }}  service: {{ properties["service"] }}  baseInstanceName: {{ env["name"] }}-instance  instanceTemplate: $(ref.{{ env["name"] }}-it.selfLink)  - name: {{ env["name"] }}-hc  type: compute.v1.httpHealthCheck  properties:  port: {{ properties["port"] }}  requestPath: /_ah/health  - name: {{ env["name"] }}-bes  type: compute.v1.backendService  properties:  port: {{ properties["port"] }}  portName: {{ properties["service"] }}  backends:  - name: {{ env["name"] }}-primary  group: $(ref.{{ env["name"] }}-pri-igm.instanceGroup)  - name: {{ env["name"] }}-secondary  group: $(ref.{{ env["name"] }}-sec-igm.instanceGroup)  healthChecks: [ $(ref.{{ env["name"] }}-hc.selfLink) ] 

   Python

   # Copyright 2016 Google Inc. All rights reserved. # # 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. """Creates primary/secondary zone autoscaled IGM running specified container.""" def GenerateConfig(context):  """Generate YAML resource configuration.""" name = context.env['name'] resources = [{ 'name': name, 'type': 'container_instance_template.py', 'properties': { 'port': context.properties['port'], 'dockerEnv': context.properties['dockerEnv'], 'dockerImage': context.properties['dockerImage'], 'containerImage': context.properties['containerImage'] } }, { 'name': name + '-pri', 'type': 'autoscaled_group.py', 'properties': { 'zone': context.properties['primaryZone'], 'size': context.properties['primarySize'], 'maxSize': context.properties['maxSize'], 'port': context.properties['port'], 'service': context.properties['service'], 'baseInstanceName': name + '-instance', 'instanceTemplate': '$(ref.' + name + '-it.selfLink)' } }, { 'name': name + '-sec', 'type': 'autoscaled_group.py', 'properties': { 'zone': context.properties['secondaryZone'], 'size': context.properties['secondarySize'], 'maxSize': context.properties['maxSize'], 'port': context.properties['port'], 'service': context.properties['service'], 'baseInstanceName': name + '-instance', 'instanceTemplate': '$(ref.' + name + '-it.selfLink)' } }, { 'name': name + '-hc', 'type': 'compute.v1.httpHealthCheck', 'properties': { 'port': context.properties['port'], 'requestPath': '/_ah/health' } }, { 'name': name + '-bes', 'type': 'compute.v1.backendService', 'properties': { 'port': context.properties['port'], 'portName': context.properties['service'], 'backends': [{ 'name': name + '-primary', 'group': '$(ref.' + name + '-pri-igm.instanceGroup)' }, { 'name': name + '-secondary', 'group': '$(ref.' + name + '-sec-igm.instanceGroup)' }], 'healthChecks': ['$(ref.' + name + '-hc.selfLink)'] } }] return {'resources': resources} 

   Create the corresponding schema file:

   Jinja

   # Copyright 2016 Google Inc. All rights reserved. # # 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. info:  title: Autoscaled IGM  author: Google  description: Creates primary/secondary zone autoscaled IGM running specified container.  version: 1.0 imports: - path: autoscaled_group.jinja - path: ../../common/jinja/container_instance_template.jinja  name: container_instance_template.jinja required: - port - service - primaryZone - secondaryZone - dockerImage properties:  primarySize:  type: integer  default: 1  description: The size of the primary autoscaled IGM  secondarySize:  type: integer  default: 0  description: The size of the secondary autoscaled IGM  maxSize:  type: integer  default: 1  description: The maximum size of the IGM  containerImage:  type: string  default: family/cos-stable  description: The container image to be used  dockerEnv:  type: object  default: {}  description: The container environment variables  dockerImage:  type: string  description: the docker image to be used  port:  type: integer  description: Port to expose on the container as well as on the load balancer (e.g., 8080)  service:  type: string  description: Name of the service the port exposes for loadbalancing (backendService) purposes  primaryZone:  type: string  description: Primary Zone in which to run the service  secondaryZone:  type: string  description: Secondary Zone in which to run the service 

   Python

   # Copyright 2016 Google Inc. All rights reserved. # # 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. info: title: Autoscaled IGM author: Google description: Creates primary/secondary zone autoscaled IGM running specified container. version: 1.0 imports: - path: autoscaled_group.py - path: ../../common/python/container_instance_template.py name: container_instance_template.py required: - port - service - primaryZone - secondaryZone - dockerImage properties: primarySize: type: integer default: 1 description: The size of the primary autoscaled IGM secondarySize: type: integer default: 0 description: The size of the secondary autoscaled IGM maxSize: type: integer default: 1 description: The maximum size of the IGM containerImage: type: string default: family/cos-stable description: The container image to be used dockerEnv: type: object default: {} description: The container environment variables dockerImage: type: string description: the docker image to be used port: type: integer description: Port to expose on the container as well as on the load balancer (e.g., 8080) service: type: string description: Name of the service the port exposes for loadbalancing (backendService) purposes primaryZone: type: string description: Primary Zone in which to run the service secondaryZone: type: string description: Secondary Zone in which to run the service 

   Let's break down what this template is creating:

   1. Two managed instance groups, one primary and one secondary.

      The template uses the autoscaled_group.[py|jinja] template to create a primary and secondary autoscaled managed instance group.

   2. Next, the template creates a backend service and health checker. A backend service is required for HTTP load balancing, and it defines the serving capacity of the instance groups in that backend service. In this case, the primary and secondary managed instance groups are part of this backend, and the default properties of the backend service apply.

      By default, a backend service performs load balancing based on CPU utilization of the associated instance groups, but you can also load balance based on requests per second (RPS).

      Note: A health check is always required when creating a backend service.

Creating a unifying template

Lastly, create a unifying template that combines both the backend and frontend templates. Create a new file named application.[py|jinja]:

 {% set BACKEND = env["deployment"] + "-backend" %} {% set FRONTEND = env["deployment"] + "-frontend" %} {% set STATIC_SERVICE = env["deployment"] + "-static-service" %} {% set APPLICATION = env["deployment"] + "-application" %} {% set APPLICATION_PORT = 8080 %} {% set LB_PORT = 8080 %} {% set MYSQL_PORT = 8080 %} {% set CONTAINER_IMAGE = "family/cos-stable" %} resources: - name: {{ BACKEND }}  type: container_vm.jinja  properties:  zone: {{ properties["primaryZone"] }}  dockerImage: {{ properties["backendImage"] }}  containerImage: {{ CONTAINER_IMAGE }}  port: {{ MYSQL_PORT }} - name: {{ FRONTEND }}  type: service.jinja  properties:  primaryZone: {{ properties["primaryZone"] }}  primarySize: 2  secondaryZone: {{ properties["secondaryZone"] }}  secondarySize: 0  dockerImage: {{ properties["frontendImage"] }}  containerImage: {{ CONTAINER_IMAGE }}  port: {{ APPLICATION_PORT }}  service: http  # If left out will default to 1  maxSize: 20  # Define the variables that are exposed to container as env variables.  dockerEnv:  SEVEN_SERVICE_MYSQL_PORT: {{ MYSQL_PORT }}  SEVEN_SERVICE_PROXY_HOST: $(ref.{{ BACKEND }}.networkInterfaces[0].networkIP) - name: {{ STATIC_SERVICE }}  type: service.jinja  properties:  primaryZone: {{ properties["primaryZone"] }}  primarySize: 2  secondaryZone: {{ properties["secondaryZone"] }}  secondarySize: 0  dockerImage: {{ properties["staticImage"] }}  containerImage: {{ CONTAINER_IMAGE }}  port: {{ APPLICATION_PORT }}  service: httpstatic  # If left out will default to 1  maxSize: 20 - name: {{ APPLICATION }}-urlmap  type: compute.v1.urlMap  properties:  defaultService: $(ref.{{ FRONTEND }}-bes.selfLink)  hostRules:  - hosts: ["*"]  pathMatcher: pathmap  pathMatchers:  - name: pathmap  defaultService: $(ref.{{ FRONTEND }}-bes.selfLink)  pathRules:  - paths: ["/static", "/static/*"]  service: $(ref.{{ STATIC_SERVICE }}-bes.selfLink) - name: {{ APPLICATION }}-targetproxy  type: compute.v1.targetHttpProxy  properties:  urlMap: $(ref.{{ APPLICATION }}-urlmap.selfLink) - name: {{ APPLICATION }}-l7lb  type: compute.v1.globalForwardingRule  properties:  IPProtocol: TCP  portRange: {{ LB_PORT }}  target: $(ref.{{ APPLICATION }}-targetproxy.selfLink) - name: {{ APPLICATION }}-fw  type: compute.v1.firewall  properties:  allowed:  - IPProtocol: TCP  ports: [ {{ LB_PORT }} ]  sourceRanges: [ 0.0.0.0/0 ] 

 # Copyright 2016 Google Inc. All rights reserved. # # 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. """Create appplication template with back-end and front-end templates.""" def GenerateConfig(context):  """Generate configuration.""" backend = context.env['deployment'] + '-backend' frontend = context.env['deployment'] + '-frontend' static_service = context.env['deployment'] + '-static-service' application = context.env['deployment'] + '-application' container_image = 'family/cos-stable' application_port = 8080 lb_port = 8080 mysql_port = 8080 resources = [{ 'name': backend, 'type': 'container_vm.py', 'properties': { 'zone': context.properties['primaryZone'], 'dockerImage': context.properties['backendImage'], 'containerImage': container_image, 'port': mysql_port } }, { 'name': frontend, 'type': 'service.py', 'properties': { 'primaryZone': context.properties['primaryZone'], 'primarySize': 2, 'secondaryZone': context.properties['secondaryZone'], 'secondarySize': 0, 'dockerImage': context.properties['frontendImage'], 'containerImage': container_image, 'port': application_port, 'service': 'http', # If left out will default to 1 'maxSize': 20, # Define the variables that are exposed to container as env variables. 'dockerEnv': { 'SEVEN_SERVICE_MYSQL_PORT': mysql_port, 'SEVEN_SERVICE_PROXY_HOST': '$(ref.' + backend + '.networkInterfaces[0].networkIP)' } } }, { 'name': static_service, 'type': 'service.py', 'properties': { 'primaryZone': context.properties['primaryZone'], 'primarySize': 2, 'secondaryZone': context.properties['secondaryZone'], 'secondarySize': 0, 'dockerImage': context.properties['staticImage'], 'containerImage': container_image, 'port': application_port, 'service': 'httpstatic', # If left out will default to 1 'maxSize': 20 } }, { 'name': application + '-urlmap', 'type': 'compute.v1.urlMap', 'properties': { 'defaultService': '$(ref.' + frontend + '-bes.selfLink)', 'hostRules': [{ 'hosts': ['*'], 'pathMatcher': 'pathmap' }], 'pathMatchers': [{ 'name': 'pathmap', 'defaultService': '$(ref.' + frontend + '-bes.selfLink)', 'pathRules': [{ 'paths': ['/static', '/static/*'], 'service': '$(ref.' + static_service + '-bes.selfLink)' }] }] } }, { 'name': application + '-targetproxy', 'type': 'compute.v1.targetHttpProxy', 'properties': { 'urlMap': '$(ref.' + application + '-urlmap.selfLink)' } }, { 'name': application + '-l7lb', 'type': 'compute.v1.globalForwardingRule', 'properties': { 'IPProtocol': 'TCP', 'portRange': lb_port, 'target': '$(ref.' + application + '-targetproxy.selfLink)' } }, { 'name': application + '-fw', 'type': 'compute.v1.firewall', 'properties': { 'allowed': [{ 'IPProtocol': 'TCP', 'ports': [lb_port] }], 'sourceRanges': ['0.0.0.0/0'] } }] return {'resources': resources} 

Create a corresponding schema file:

# Copyright 2016 Google Inc. All rights reserved. # # 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. info:  title: Application Template  author: Google  description: Create application template with back-end and front-end templates  version: 1.0 imports: - path: service.jinja - path: ../../common/jinja/container_vm.jinja  name: container_vm.jinja required: - primaryZone - secondaryZone - backendImage - frontendImage - staticImage properties:  primaryZone:  type: string  description: Primary Zone in which to run the service  secondaryZone:  type: string  description: Secondary Zone in which to run the service  backendImage:  type: string  description: Docker image to use in the backend  frontendImage:  type: string  description: Docker image to use in the frontend service  staticImage:  type: string  description: Docker image to use in the static service 

# Copyright 2016 Google Inc. All rights reserved. # # 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. info: title: Application Template author: Google description: Create application template with back-end and front-end templates version: 1.0 imports: - path: service.py - path: ../../common/python/container_vm.py name: container_vm.py required: - primaryZone - secondaryZone - backendImage - frontendImage - staticImage properties: primaryZone: type: string description: Primary Zone in which to run the service secondaryZone: type: string description: Secondary Zone in which to run the service backendImage: type: string description: Docker image to use in the backend frontendImage: type: string description: Docker image to use in the frontend service staticImage: type: string description: Docker image to use in the static service 

In addition to the frontend and backend, the template also defines some additional resources:

1. A static service with primary and secondary managed instance groups. This static service serves a webpage located at the /static path in your app.

2. A URL Map resource. HTTP load balancing requires a URL map to map the different URLs to correct paths. In this case, the default path, indicated by the defaultService property, is the backend service that you created earlier. If a user navigates to /static, the URL map will map that path to the static service, as defined in the pathMatchers section.

3. A global forwarding rule and target HTTP proxy. Since the app is being load balanced across two separate zones, you will need a global forwarding rule that serves a single external IP address. In addition, a target HTTP proxy is required for the HTTP load balancing setup.

4. A firewall rule that allows traffic through port 8080.

Creating your configuration

Now that you have your templates and related schemas ready, you can create a configuration that deploys these resources. Create a configuration file named application.yaml with the following contents, and replace ZONE_TO_RUN and SECONDARY_ZONE_TO_RUN with the primary and secondary zones of your choice.

# Copyright 2016 Google Inc. All rights reserved. # # 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. # Launches an autoscaled, load-balanced frontend in two zones running nodejs # for serving traffic using L7 loadbalancing. Also launches a single MySQL # container instance, wires the two together using references, and passes # them as env variables to the underlying frontend Docker containers. # # NOTE: Due to the fact that IGM does not allow specifying service/port to # created IG, you must run the following commands after creation of the # template: # # export DEPLOYMENT=<DEPLOYMENT NAME> # export PRIMARY_ZONE=<PRIMARY ZONE> # export SECONDARY_ZONE=<SECONDARY ZONE> # # gcloud compute instance-groups unmanaged set-named-ports ${DEPLOYMENT}-frontend-pri-igm \ # --named-ports http:8080,httpstatic:8080 \ # --zone ${PRIMARY_ZONE} # # gcloud compute instance-groups unmanaged set-named-ports ${DEPLOYMENT}-frontend-sec-igm \ # --named-ports http:8080,httpstatic:8080 \ # --zone ${SECONDARY_ZONE} # # Then to see the IP that exposes the application, you can do: # gcloud compute forwarding-rules list | grep application-${DEPLOYMENT}-l7lb imports: - path: application.jinja resources: - name: nodejs  type: application.jinja  properties:  primaryZone: ZONE_TO_RUN  secondaryZone: SECOND_ZONE_TO_RUN  backendImage: gcr.io/deployment-manager-examples/mysql  frontendImage: gcr.io/deployment-manager-examples/nodejsservice  staticImage: gcr.io/deployment-manager-examples/nodejsservicestatic 

# Copyright 2016 Google Inc. All rights reserved. # # 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. # Launches an autoscaled, load-balanced frontend in two zones running nodejs # for serving traffic using L7 loadbalancing. Also launches a single MySQL # container instance, wires the two together using references, and passes # them as env variables to the underlying frontend Docker containers. # # NOTE: Due to the fact that IGM does not allow specifying service/port to # created IG, you must run the following commands after creation of the # template: # # export DEPLOYMENT=<DEPLOYMENT NAME> # export PRIMARY_ZONE=<PRIMARY ZONE> # export SECONDARY_ZONE=<SECONDARY ZONE> # # gcloud compute instance-groups unmanaged set-named-ports ${DEPLOYMENT}-frontend-pri-igm \ # --named-ports http:8080,httpstatic:8080 \ # --zone ${PRIMARY_ZONE} # # gcloud compute instance-groups unmanaged set-named-ports ${DEPLOYMENT}-frontend-sec-igm \ # --named-ports http:8080,httpstatic:8080 \ # --zone ${SECONDARY_ZONE} # # Then to see the IP that exposes the application, you can do: # gcloud compute forwarding-rules list | grep application-${DEPLOYMENT}-l7lb imports: - path: application.py resources: - name: nodejs  type: application.py  properties:  primaryZone: ZONE_TO_RUN  secondaryZone: SECOND_ZONE_TO_RUN  backendImage: gcr.io/deployment-manager-examples/mysql  frontendImage: gcr.io/deployment-manager-examples/nodejsservice  staticImage: gcr.io/deployment-manager-examples/nodejsservicestatic 

Deploying your configuration

Now, let's deploy your resources. Using the Google Cloud CLI, run the following command, optionally choosing to replace advanced-configuration-l7 with a deployment name of your choice. Keep in mind that your deployment name will automatically be used to name the resources.

In this example, the deployment name is advanced-configuration-l7. If you opt to change the deployment name, make sure to use that deployment name in all of the following examples.

gcloud deployment-manager deployments create advanced-configuration-l7 --config application.yaml 

The response should look similar to the following resources:

Waiting for create operation-1469468950934-5387966d431f0-49b11bc4-1421b2f0...done. Create operation operation-1469468950934-5387966d431f0-49b11bc4-1421b2f0 completed successfully. NAME TYPE STATE ERRORS advanced-configuration-l7-application-fw compute.v1.firewall COMPLETED [] advanced-configuration-l7-application-l7lb compute.v1.globalForwardingRule COMPLETED [] advanced-configuration-l7-application-targetproxy compute.v1.targetHttpProxy COMPLETED [] advanced-configuration-l7-application-urlmap compute.v1.urlMap COMPLETED [] advanced-configuration-l7-backend compute.v1.instance COMPLETED [] advanced-configuration-l7-frontend-bes compute.v1.backendService COMPLETED [] advanced-configuration-l7-frontend-hc compute.v1.httpHealthCheck COMPLETED [] advanced-configuration-l7-frontend-it compute.v1.instanceTemplate COMPLETED [] advanced-configuration-l7-frontend-pri-as compute.v1.autoscaler COMPLETED [] advanced-configuration-l7-frontend-pri-igm compute.v1.instanceGroupManager COMPLETED [] advanced-configuration-l7-frontend-sec-as compute.v1.autoscaler COMPLETED [] advanced-configuration-l7-frontend-sec-igm compute.v1.instanceGroupManager COMPLETED [] advanced-configuration-l7-static-service-bes compute.v1.backendService COMPLETED [] advanced-configuration-l7-static-service-hc compute.v1.httpHealthCheck COMPLETED [] advanced-configuration-l7-static-service-it compute.v1.instanceTemplate COMPLETED [] advanced-configuration-l7-static-service-pri-as compute.v1.autoscaler COMPLETED [] advanced-configuration-l7-static-service-pri-igm compute.v1.instanceGroupManager COMPLETED [] advanced-configuration-l7-static-service-sec-as compute.v1.autoscaler COMPLETED [] advanced-configuration-l7-static-service-sec-igm compute.v1.instanceGroupManager COMPLETED []

Adding service labels

Next, specify the appropriate service labels for your managed instance groups. Service labels are metadata used by the load balancing service to group resources.

To add service labels, run the following commands, matching the primary and secondary zones to the zones you selected in your deployment configuration file:

gcloud compute instance-groups unmanaged set-named-ports advanced-configuration-l7-frontend-pri-igm \  --named-ports http:8080,httpstatic:8080 \  --zone [PRIMARY_ZONE] gcloud compute instance-groups unmanaged set-named-ports advanced-configuration-l7-frontend-sec-igm \  --named-ports http:8080,httpstatic:8080 \  --zone [SECONDARY_ZONE] 

Testing your configuration

To test your configuration, get the external IP address that is serving traffic by querying the forwarding rule:

gcloud compute forwarding-rules list | grep advanced-configuration-l7-l7lb advanced-configuration-l7-l7lb 107.178.249.126 TCP advanced-configuration-l7-targetproxy

In this case, the external IP is 107.178.249.126.

In a browser, visit the external IP address at port 8080. For example, if your external IP is 107.178.249.126, the URL would be:

http://107.178.249.126:8080 

You should see a blank page, which is expected. Next, post a message to the page. Go to the following URL:

http://107.178.249.126:8080?msg=hello_world! 

You will see confirmation that your message was added. Navigate back to the main URL and now the page should have the message:

hello_world! 

You can also visit the static page you created, or check the health of your app, by visiting the following URLs:

# Static web page http://107.178.249.126:8080/static # Health check http://107.178.249.126:8080/_ah/health 

Congratulations, you've deployed your configuration successfully.

(Optional) Creating Docker images

Docker allows you to automate and run software inside containers. Containers allow you to isolate different services within containers that can all run on a single Linux instance.

This example used some existing Docker images, but you can also create your own versions of these Docker images. You can find the instructions for creating the MySQL backend images and the Node.js frontend images in the Creating your resource templates section.

To create the Docker image that serves the static webpage:

1. Create a new VM instance with a container-optimized image:

   gcloud compute instances create docker-playground \  --image-family container-vm \  --image-project google-containers \  --zone us-central1-a \  --machine-type f1-micro 

2. Connect to the instance:

   gcloud compute ssh --zone us-central1-a docker-playground 

3. Create a file named Dockerfile with the following contents:

   FROM node:latest RUN mkdir /var/www/ ADD service.js /var/www/service.js WORKDIR /var/www/ RUN npm install mysql CMD ["node", "service.js"] 

4. Create a file named service.js with the following contents:

   var http = require('http'); var url = require('url'); console.log('Started static node server') http.createServer(function (req, res) {  reqUrl = url.parse(req.url, true);  res.useChunkedEncodingByDefault = false;  res.writeHead(200, {'Content-Type': 'text/html'});  if (reqUrl.pathname == '/_ah/health') {  res.end('ok');  } else if (reqUrl.pathname == '/exit') {  process.exit(-1)  } else {  res.end('static server');  } }).listen(8080, '0.0.0.0'); console.log('Static server running at http://127.0.0.1:8080/'); 

5. Build the Docker image, replacing username with your Docker Hub username. If you do not have a Docker Hub username, create one first before building the Docker image.

   sudo docker build --no-cache -t username/nodejsservicestatic . 

6. Push the images to the Docker repository:

   sudo docker push username/nodejsservicestatic 

Now you have the Docker images to run Node.js and MySQL. You can actually see these images on the repository by searching for the image names. To try the images out, you can replace all instances of gcr.io/deployment-manager-examples/mysql and gcr.io/deployment-manager-examples/nodejsservice with your respective images.

Next steps

Once you've completed this sample, you can:

• Continue to build off of this example by creating a more robust webpage, or adding more services to the web server.
• Read more about configurations or deployments.
• Try creating your own configurations.