Criar uma app de registo de viagens com balanceamento de carga HTTP

Este exemplo avançado demonstra como criar uma app de registo que usa o node.js para o respetivo frontend e o MySQL para o respetivo backend. O modelo também cria e liga um balanceador de carga HTTP que equilibra a carga em duas zonas, e um escalador automático para dimensionar automaticamente a app.

Recursos de implementação com equilíbrio de carga HTTP
Recursos de implementação com balanceamento de carga HTTP (clique para aumentar)

Este exemplo pressupõe que conhece os contentores Docker, bem como os recursos do Compute Engine, particularmente o balanceamento de carga HTTP, a escala automática, os grupos de instâncias geridas e os modelos de instâncias.

Para ver mais tutoriais introdutórios, consulte o guia de introdução ou o guia passo a passo.

Antes de começar

Criar os seus modelos

Este exemplo inicia uma implementação com vários tipos de recursos. Para começar, vai criar modelos reutilizáveis que definem estes recursos separadamente. Mais tarde, vai usar estes modelos na configuração final.

No final deste exemplo, terá uma implementação que contém estes recursos:

  • Uma única instância do Compute Engine para a máquina virtual MySQL de back-end.
  • Um modelo de instância que usa uma imagem do Docker.
  • Dois grupos de instâncias geridos com escalamento automático em duas zonas diferentes, a executar o serviço node.js de front-end.
  • Outro grupo de instâncias gerido com escala automática que serve dados estáticos.
  • Uma verificação de estado e um balanceador de carga HTTP para distribuir o tráfego pelos respetivos grupos de instâncias geridas.

Criar os modelos de back-end

O back-end desta app é uma única instância do Compute Engine que executa um contentor do Docker do MySQL. Crie um modelo que defina uma instância do Compute Engine que use uma imagem otimizada para contentores. Atribua o nome container_vm.[py|jinja] ao ficheiro:

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

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


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

O modelo define várias variáveis, como containerImage e manifest, que são preenchidas quando define a sua configuração. Este modelo sozinho apenas cria uma instância de máquina virtual (VM).

Quando usa imagens de contentores em instâncias do Compute Engine, também tem de fornecer um ficheiro de manifesto (diferente de um manifesto do Deployment Manager) para descrever ao Compute Engine que imagem de contentor usar. Crie um método auxiliar denominado container_helper.[py|jinja] para definir dinamicamente o manifesto do contentor:

Jinja



{% 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 -%}

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.

"""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)

Criar os modelos de front-end

O frontend desta app é executado no Node.js e permite que os utilizadores publiquem mensagens na página Web. Existem dois grupos de instâncias geridas que contêm duas instâncias cada: um grupo de instâncias geridas principal e um grupo de instâncias geridas secundário para o equilíbrio de carga.

Para criar estes modelos de front-end, use as seguintes instruções.

  1. Crie um modelo de instância.

    Precisa de um recurso de modelo de instância para criar um grupo de instâncias geridas, que é um grupo de instâncias de VMs idênticas geridas centralmente. Este exemplo cria um grupo de instâncias gerido para as instâncias do Node.js de front-end, mas primeiro tem de criar o modelo de instância.

    Defina um ficheiro com o nome 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. Crie um grupo de instâncias gerido com escalamento automático.

    Agora que tem um modelo de instância, pode definir um modelo que use o modelo de instância para criar um grupo de instâncias geridas com escalamento automático. Crie um novo ficheiro denominado autoscaled_group.[py|jinja] com o seguinte conteúdo:

    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}
    

    Crie o ficheiro de esquema correspondente:

    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. Crie recursos com estes modelos.

    Até este ponto, definiu modelos base que determinam as propriedades dos seus recursos. Com estes modelos, defina a configuração do seu front-end. Crie um novo ficheiro denominado service.[py|jinja] com o seguinte conteúdo:

    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}
    

    Crie o ficheiro de esquema correspondente:

    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
    

    Vamos analisar o que este modelo está a criar:

    1. Dois grupos de instâncias geridas, um principal e um secundário.

      O modelo usa o modelo autoscaled_group.[py|jinja] para criar um grupo de instâncias gerido com escalamento automático primário e secundário.

    2. Em seguida, o modelo cria um serviço de back-end e um verificador de funcionamento. É necessário um serviço de back-end para o balanceamento de carga HTTP, e este define a capacidade de publicação dos grupos de instâncias nesse serviço de back-end. Neste caso, os grupos de instâncias geridas principais e secundários fazem parte deste back-end, e as propriedades predefinidas do serviço de back-end aplicam-se.

      Por predefinição, um serviço de back-end realiza o equilíbrio de carga com base na utilização da CPU dos grupos de instâncias associados, mas também pode fazer o equilíbrio de carga com base em pedidos por segundo (RPS).

      Nota: uma verificação de funcionamento é sempre necessária quando cria um serviço de back-end.

Criar um modelo unificador

Por último, crie um modelo unificador que combine os modelos de back-end e front-end. Crie um novo ficheiro com o nome application.[py|jinja]:

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 ]

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.

"""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}

Crie um ficheiro de esquema correspondente:

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: 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

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: 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

Além do front-end e do back-end, o modelo também define alguns recursos adicionais:

  1. Um serviço estático com grupos de instâncias geridas primários e secundários. Este serviço estático disponibiliza uma página Web localizada no caminho /static na sua app.

  2. Um recurso de mapa de URL. O balanceamento de carga HTTP requer um mapa de URLs para mapear os diferentes URLs para os caminhos corretos. Neste caso, o caminho predefinido, indicado pela propriedade defaultService, é o serviço de back-end que criou anteriormente. Se um utilizador navegar para /static, o mapa de URLs mapeia esse caminho para o serviço estático, conforme definido na secção pathMatchers.

  3. Uma regra de encaminhamento global e um proxy HTTP de destino. Uma vez que a app está a ser balanceada em duas zonas separadas, precisa de uma regra de encaminhamento global que publique um único endereço IP externo. Além disso, é necessário um proxy HTTP de destino para a configuração do balanceamento de carga HTTP.

  4. Uma regra de firewall que permite o tráfego através da porta 8080.

A criar a sua configuração

Agora que tem os modelos e os esquemas relacionados prontos, pode criar uma configuração que implemente estes recursos. Crie um ficheiro de configuração denominado application.yaml com o seguinte conteúdo e substitua ZONE_TO_RUN e SECONDARY_ZONE_TO_RUN pelas zonas primárias e secundárias da sua escolha.

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.

# 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

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.

# 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

Implementar a configuração

Agora, vamos implementar os seus recursos. Usando a CLI Google Cloud, execute o comando seguinte, escolhendo opcionalmente substituir advanced-configuration-l7 por um nome de implementação à sua escolha. Tenha em atenção que o nome da implementação vai ser usado automaticamente para dar nome aos recursos.

Neste exemplo, o nome da implementação é advanced-configuration-l7. Se optar por alterar o nome da implementação, certifique-se de que usa esse nome da implementação em todos os exemplos seguintes.

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

A resposta deve ter um aspeto semelhante aos seguintes recursos:

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  []

Adicionar etiquetas de serviço

Em seguida, especifique as etiquetas de serviço adequadas para os seus grupos de instâncias geridos. As etiquetas de serviço são metadados usados pelo serviço de equilíbrio de carga para agrupar recursos.

Para adicionar etiquetas de serviço, execute os seguintes comandos, fazendo corresponder as zonas primárias e secundárias às zonas que selecionou no ficheiro de configuração da implementação:

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]

Testar a configuração

Para testar a sua configuração, obtenha o endereço IP externo que está a publicar tráfego consultando a regra de encaminhamento:

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

Neste caso, o IP externo é 107.178.249.126.

Num navegador, visite o endereço IP externo na porta 8080. Por exemplo, se o seu IP externo for 107.178.249.126, o URL seria:

http://107.178.249.126:8080

Deve ver uma página em branco, o que é esperado. Em seguida, publique uma mensagem na página. Aceda ao seguinte URL:

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

É apresentada uma confirmação de que a mensagem foi adicionada. Regresse ao URL principal e, agora, a página deve ter a mensagem:

hello_world!

Também pode visitar a página estática que criou ou verificar o estado da sua app através dos seguintes URLs:

# Static web page
http://107.178.249.126:8080/static

# Health check
http://107.178.249.126:8080/_ah/health

Parabéns! Implementou a sua configuração com êxito.

(Opcional) Criar imagens de Docker

O Docker permite-lhe automatizar e executar software em contentores. Os contentores permitem-lhe isolar diferentes serviços em contentores que podem ser executados numa única instância do Linux.

Este exemplo usou algumas imagens do Docker existentes, mas também pode criar as suas próprias versões destas imagens do Docker. Pode encontrar as instruções para criar as imagens de back-end do MySQL e as imagens de front-end do Node.js na secção Criar os modelos de recursos.

Para criar a imagem do Docker que publica a página Web estática:

  1. Crie uma nova instância de VM com uma imagem otimizada para contentores:

    gcloud compute instances create docker-playground \
      --image-family container-vm \
      --image-project google-containers \
      --zone us-central1-a \
      --machine-type f1-micro
    
  2. Associe-se à instância:

    gcloud compute ssh --zone us-central1-a docker-playground
    
  3. Crie um ficheiro denominado Dockerfile com o seguinte conteúdo:

    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. Crie um ficheiro denominado service.js com o seguinte conteúdo:

    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. Crie a imagem do Docker, substituindo username pelo seu nome de utilizador do Docker Hub. Se não tiver um nome de utilizador do Docker Hub, crie um primeiro antes de criar a imagem do Docker.

    sudo docker build --no-cache -t username/nodejsservicestatic .
    
  6. Envie as imagens para o repositório Docker:

    sudo docker push username/nodejsservicestatic
    

Agora, tem as imagens Docker para executar o Node.js e o MySQL. Pode ver estas imagens no repositório pesquisando os nomes das imagens. Para experimentar as imagens, pode substituir todas as instâncias de gcr.io/deployment-manager-examples/mysql e gcr.io/deployment-manager-examples/nodejsservice pelas suas respetivas imagens.

Passos seguintes

Depois de concluir este exemplo, pode:

  • Continue a desenvolver este exemplo criando uma página Web mais robusta ou adicionando mais serviços ao servidor Web.
  • Leia mais sobre as configurações ou as implementações.
  • Experimente criar as suas próprias configurações.