Elastic Beanstalk 内の EC2 インスタンス一覧を生成する fabfile

fabfile.py

# -*- coding: utf-8 -*-
import json
import boto
import boto.beanstalk
import boto.ec2
from fabric.api import task, puts

# Elastic Beanstalk の Applicaton 名
EB_APP_NAME = 'example-app'
# Elastic Beanstalk の リージョン名
EB_REGION = 'ap-northeast-1'


def _get_eb_conn():
    """ Beanstalk の conn オブジェクトを取得する
    """
    region = [r for r in boto.beanstalk.regions() if r.name == EB_REGION][0]
    return boto.connect_beanstalk(region=region)


def _get_ec2_conn():
    """ EC2 の conn オブジェクトを取得する
    """
    region = [r for r in boto.ec2.regions() if r.name == EB_REGION][0]
    return boto.connect_ec2(region=region)


def _get_eb_environments():
    """ Application 内の Environment 一覧を返す
    """
    conn = _get_eb_conn()
    res = conn.describe_environments(application_name=EB_APP_NAME)
    return res['DescribeEnvironmentsResponse']['DescribeEnvironmentsResult']['Environments']


@task
def generate_spec_servers():
    """ Application 内の EC2 で severs.json を生成する
    """
    puts('Start generate spec/env/servers.json for serverspec')
    envs = _get_eb_environments()
    eb_conn = _get_eb_conn()
    ec2_conn = _get_ec2_conn()
    servers = []
    for e in envs:
        env_name = e['EnvironmentName']
        if 'production' in env_name:
            host = 'foo-production'
        elif 'staging' in env_name:
            host = 'foo-staging'
        res = eb_conn.describe_environment_resources(environment_id=e['EnvironmentId'])
        instances = res['DescribeEnvironmentResourcesResponse']['DescribeEnvironmentResourcesResult']['EnvironmentResources']['Instances']
        for ins in ec2_conn.get_only_instances(instance_ids=[i['Id'] for i in instances]):
            servers.append({
                'name': '{}-{}'.format(env_name, ins.private_ip_address),
                'host': host,
                'hostname': ins.private_ip_address,
                'roles': ['base']
            })
    with open('spec/env/hosts2.json', 'w') as f:
        f.write(json.dumps(servers, indent=2))
    puts('Completed')