Usar módulos de plantilla

Los módulos de plantilla son archivos auxiliares que realizan funciones específicas que pueden hacer que tus plantillas sean más eficientes. Por ejemplo, puedes tener un módulo que genere nombres únicos para tus recursos. Deployment Manager puede ejecutar cualquier módulo escrito en Python o Jinja.

Antes de empezar

Crear un módulo de plantilla

Un módulo de plantilla se trata como un archivo de plantilla normal y se puede escribir en Jinja o Python.

Por ejemplo, a continuación se muestra una plantilla auxiliar que genera un nombre a partir de un prefijo y un sufijo.

Jinja


En Jinja, esta plantilla auxiliar (en este ejemplo, llamada helpers/common.jinja) tendría el siguiente aspecto:



{%- macro GenerateMachineName(prefix='', suffix='') -%}
    {{ prefix + "-" + suffix }}
{%- endmacro %}

Después, puedes importar esta plantilla y usarla como módulo. En tu plantilla de Jinja, puedes usar el módulo de la siguiente manera:

# 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.


{% import 'helpers/common.jinja' as common %}

resources:
- name: {{ common.GenerateMachineName("myfrontend", "prod") }}
  type: compute.v1.instance
  properties:
    zone: us-central1-f
    machineType: https://www.googleapis.com/compute/v1/projects/{{ env['project'] }}/zones/us-central1-f/machineTypes/f1-micro
    disks:
    - deviceName: boot
      type: PERSISTENT
      boot: true
      autoDelete: true
      initializeParams:
        sourceImage: https://www.googleapis.com/compute/v1/projects/debian-cloud/global/images/family/debian-11
    networkInterfaces:
    - network: https://www.googleapis.com/compute/v1/projects/{{ env['project'] }}/global/networks/default
      accessConfigs:
      - name: External NAT
        type: ONE_TO_ONE_NAT

A continuación, la configuración debe importar ambos archivos (incluido el archivo helpers/common.jinja):

# Copyright 2015 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.

imports:
- path: helpers/common.jinja
- path: vm-instance-example.jinja

resources:
- name: my-vm
  type: vm-instance-example.jinja

El servicio Deployment Manager ampliará la configuración y la configuración final será la siguiente:

resources:
- name: myfrontend-prod
  type: compute.v1.instance
  properties:
    zone: us-central1-f
    machineType: https://www.googleapis.com/compute/v1/projects/myproject/zones/us-central1-f/machineTypes/f1-micro
    disks:
    - deviceName: boot
      type: PERSISTENT
      boot: true
      autoDelete: true
      initializeParams:
        sourceImage: https://www.googleapis.com/compute/v1/projects/debian-cloud/global/images/family/debian-9
    networkInterfaces:
    - network: https://www.googleapis.com/compute/v1/projects/myproject/global/networks/default
      accessConfigs:
      - name: External NAT
        type: ONE_TO_ONE_NAT

Python


En Python, la plantilla auxiliar (en este ejemplo, llamada helpers/common.py) tendría este aspecto:

# 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.

"""Generates name of a VM."""


def GenerateMachineName(prefix, suffix):
  return prefix + "-" + suffix

Para usarlo en tu plantilla de 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.

"""Constructs a VM with imported module."""
from helpers import common

COMPUTE_URL_BASE = 'https://www.googleapis.com/compute/v1/'


def GenerateConfig(context):
  """Generates configuration of a VM."""
  resources = [{
      'name': common.GenerateMachineName('myfrontend', 'prod'),
      'type': 'compute.v1.instance',
      'properties': {
          'zone': 'us-central1-f',
          'machineType': COMPUTE_URL_BASE + 'projects/' + context.env['project']
                         + '/zones/us-central1-f/machineTypes/f1-micro',
          'disks': [{
              'deviceName': 'boot',
              'type': 'PERSISTENT',
              'boot': True,
              'autoDelete': True,
              'initializeParams': {
                  'sourceImage': COMPUTE_URL_BASE + 'projects/'
                                 'debian-cloud/global/images/family/debian-11'}
          }],
          'networkInterfaces': [{
              'network': COMPUTE_URL_BASE + 'projects/' + context.env['project']
                         + '/global/networks/default',
              'accessConfigs': [{
                  'name': 'External NAT',
                  'type': 'ONE_TO_ONE_NAT'
              }]
          }]
      }
  }]
  return {'resources': resources}

A continuación, la configuración debe importar ambos archivos (incluido el archivo helpers/common.py):

# Copyright 2015 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.

imports:
- path: helpers/common.py
- path: vm-instance-example.py

resources:
- name: my-vm
  type: vm-instance-example.py

Aquí tienes un módulo auxiliar más complejo:

# Copyright 2015 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 common
import default
import yaml

# Specific properties for this component, also see container_instance
DCKRENV = default.DCKRENV
DCKRIMAGE = default.DCKRIMAGE

MANIFEST = """
version: v1beta2
containers:
  - name: %(name)s
    image: %(dockerImage)s
    ports:
      - name: %(name)s-port
        hostPort: %(port)i
        containerPort: %(port)i
    %(env)s
"""


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 = ""
  env_list = []
  if DCKRENV in context.properties:
    for key, value in context.properties[DCKRENV].iteritems():
      env_list.append({"name": key, "value": value})
  if env_list:
    env = "env: " + yaml.dump(env_list, default_flow_style=True)

  manifest_yaml_string = MANIFEST % {
      "name": context.env["name"],
      "dockerImage": context.properties[DCKRIMAGE],
      "port": context.properties[default.PORT],
      "env": env
  }
  return common.GenerateEmbeddableYaml(manifest_yaml_string)

Siguientes pasos