如何将更新的Docker映像部署到Amazon ECS任务? [英] How do I deploy updated Docker images to Amazon ECS tasks?

问题描述

什么是使我的 Amazon ECS 任务更新其Docker映像的正确方法，是否在相应的注册表中更新了所述图片?

What is the right approach to make my Amazon ECS tasks update their Docker images, once said images have been updated in the corresponding registry?

推荐答案

我创建了

I created a script for deploying updated Docker images to a staging service on ECS, so that the corresponding task definition refers to the current versions of the Docker images. I don't know for sure if I'm following best practices, so feedback would be welcome.

要使脚本正常工作，您需要备用ECS实例或 deploymentConfiguration.minimumHealthyPercent 值，以便ECS可以窃取实例以将更新的任务定义部署到该实例.

For the script to work, you need either a spare ECS instance or a deploymentConfiguration.minimumHealthyPercent value so that ECS can steal an instance to deploy the updated task definition to.

我的算法是这样的:

1. 使用Git修订版在任务定义中标记与容器相对应的Docker映像.
2. 将Docker映像标签推送到相应的注册表.
3. 在任务定义族中注销旧的任务定义.
4. 注册新的任务定义，现在引用标记有当前Git版本的Docker映像.
5. 更新服务以使用新的任务定义.

我的代码粘贴如下:

#!/usr/bin/env python3
import subprocess
import sys
import os.path
import json
import re
import argparse
import tempfile

_root_dir = os.path.abspath(os.path.normpath(os.path.dirname(__file__)))
sys.path.insert(0, _root_dir)
from _common import *


def _run_ecs_command(args):
    run_command(['aws', 'ecs', ] + args)


def _get_ecs_output(args):
    return json.loads(run_command(['aws', 'ecs', ] + args, return_stdout=True))


def _tag_image(tag, qualified_image_name, purge):
    log_info('Tagging image \'{}\' as \'{}\'...'.format(
        qualified_image_name, tag))
    log_info('Pulling image from registry in order to tag...')
    run_command(
        ['docker', 'pull', qualified_image_name], capture_stdout=False)
    run_command(['docker', 'tag', '-f', qualified_image_name, '{}:{}'.format(
        qualified_image_name, tag), ])
    log_info('Pushing image tag to registry...')
    run_command(['docker', 'push', '{}:{}'.format(
        qualified_image_name, tag), ], capture_stdout=False)
    if purge:
        log_info('Deleting pulled image...')
        run_command(
            ['docker', 'rmi', '{}:latest'.format(qualified_image_name), ])
        run_command(
            ['docker', 'rmi', '{}:{}'.format(qualified_image_name, tag), ])


def _register_task_definition(task_definition_fpath, purge):
    with open(task_definition_fpath, 'rt') as f:
        task_definition = json.loads(f.read())

    task_family = task_definition['family']

    tag = run_command([
        'git', 'rev-parse', '--short', 'HEAD', ], return_stdout=True).strip()
    for container_def in task_definition['containerDefinitions']:
        image_name = container_def['image']
        _tag_image(tag, image_name, purge)
        container_def['image'] = '{}:{}'.format(image_name, tag)

    log_info('Finding existing task definitions of family \'{}\'...'.format(
        task_family
    ))
    existing_task_definitions = _get_ecs_output(['list-task-definitions', ])[
        'taskDefinitionArns']
    for existing_task_definition in [
        td for td in existing_task_definitions if re.match(
            r'arn:aws:ecs+:[^:]+:[^:]+:task-definition/{}:\d+'.format(
                task_family),
            td)]:
        log_info('Deregistering task definition \'{}\'...'.format(
            existing_task_definition))
        _run_ecs_command([
            'deregister-task-definition', '--task-definition',
            existing_task_definition, ])

    with tempfile.NamedTemporaryFile(mode='wt', suffix='.json') as f:
        task_def_str = json.dumps(task_definition)
        f.write(task_def_str)
        f.flush()
        log_info('Registering task definition...')
        result = _get_ecs_output([
            'register-task-definition',
            '--cli-input-json', 'file://{}'.format(f.name),
        ])

    return '{}:{}'.format(task_family, result['taskDefinition']['revision'])


def _update_service(service_fpath, task_def_name):
    with open(service_fpath, 'rt') as f:
        service_config = json.loads(f.read())
    services = _get_ecs_output(['list-services', ])[
        'serviceArns']
    for service in [s for s in services if re.match(
        r'arn:aws:ecs:[^:]+:[^:]+:service/{}'.format(
            service_config['serviceName']),
        s
    )]:
        log_info('Updating service with new task definition...')
        _run_ecs_command([
            'update-service', '--service', service,
            '--task-definition', task_def_name,
        ])


parser = argparse.ArgumentParser(
    description="""Deploy latest Docker image to staging server.
The task definition file is used as the task definition, whereas
the service file is used to configure the service.
""")
parser.add_argument(
    'task_definition_file', help='Your task definition JSON file')
parser.add_argument('service_file', help='Your service JSON file')
parser.add_argument(
    '--purge_image', action='store_true', default=False,
    help='Purge Docker image after tagging?')
args = parser.parse_args()

task_definition_file = os.path.abspath(args.task_definition_file)
service_file = os.path.abspath(args.service_file)

os.chdir(_root_dir)

task_def_name = _register_task_definition(
    task_definition_file, args.purge_image)
_update_service(service_file, task_def_name)

_common.py

import sys
import subprocess


__all__ = ['log_info', 'handle_error', 'run_command', ]


def log_info(msg):
    sys.stdout.write('* {}\n'.format(msg))
    sys.stdout.flush()


def handle_error(msg):
    sys.stderr.write('* {}\n'.format(msg))
    sys.exit(1)


def run_command(
        command, ignore_error=False, return_stdout=False, capture_stdout=True):
    if not isinstance(command, (list, tuple)):
        command = [command, ]
    command_str = ' '.join(command)
    log_info('Running command {}'.format(command_str))
    try:
        if capture_stdout:
            stdout = subprocess.check_output(command)
        else:
            subprocess.check_call(command)
            stdout = None
    except subprocess.CalledProcessError as err:
        if not ignore_error:
            handle_error('Command failed: {}'.format(err))
    else:
        return stdout.decode() if return_stdout else None

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