ELBから1台ずつEC2インスタンスを切り離して、アプリケーションをデプロイしてリスタート、終わったら、ELBにEC2インスタンスを追加します。
なぜ、Fabricを使ったかというと、ほかのデプロイ自動化ツール、たとえばCapistranoやAnsibleだと、ELBのAPIを叩く処理を書くのがちょっと面倒そうだったからです。Fabricなら使いやすそうなPythonライブラリがあり、簡潔に書けるな、と考えたからです。
以下のFabricスクリプトは、ロールバックやヘルスチェックなどの処理を書いていません。もうちょっと高級なことがしたかったら、他の方法を考えたりするといいと思います。
※ ELBは、Classic load balancerを使っています。
Fabricのインストール
環境：Mac OS X
$ sudo easy_install fabric $ sudo pip install boto $ fab --version Fabric 1.11.1 Paramiko 1.17.1Fabricスクリプト
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| from fabric.api import * | |
| from fabric.decorators import runs_once | |
| import boto.ec2.elb | |
| # EC2 settings | |
| REGION = "ap-northeast-1" | |
| AWS_ACCESS_KEY_ID = 'XXXXXXXXXX' | |
| AWS_SECRET_ACCESS_KEY = 'XXXXXXXXXX' | |
| ELB_NAME = 'my-elb' | |
| SLEEP_TIME = 20 | |
| # Deploy setting | |
| ORIGIN_APP_DIR = "/Users/yako/Desktop/myapp" | |
| DEPLOY_DIR = "/usr/local/src" | |
| # Init ELB | |
| elb_connection = boto.ec2.elb.connect_to_region( | |
| REGION, | |
| aws_access_key_id = AWS_ACCESS_KEY_ID, | |
| aws_secret_access_key = AWS_SECRET_ACCESS_KEY) | |
| elb = elb_connection.get_all_load_balancers(ELB_NAME)[0] | |
| # App operations | |
| @task | |
| def put_app(): | |
| put(ORIGIN_APP_DIR, '%s/' % DEPLOY_DIR) | |
| @task | |
| def app_start(): | |
| sudo("service myapp start") | |
| @task | |
| def app_stop(): | |
| sudo("service myapp stop") | |
| @task | |
| def app_restart(): | |
| sudo("service myapp restart") | |
| # ELB operations | |
| def get_ec2_id(): | |
| return run("curl http://169.254.169.254/latest/meta-data/instance-id") | |
| @task | |
| def remove_ec2_from_elb(): | |
| ec2_id = get_ec2_id() | |
| elb.deregister_instances(ec2_id) | |
| print("\n=> Removed %s from %s\n" % (ec2_id, ELB_NAME)) | |
| @task | |
| def add_ec2_to_elb(): | |
| ec2_id = get_ec2_id() | |
| elb.register_instances(ec2_id) | |
| print("\n=> Add %s to %s\n" % (ec2_id, ELB_NAME)) | |
| # Deploy operations | |
| @task | |
| def all(): | |
| remove_ec2_from_elb() | |
| run('sleep %s' % SLEEP_TIME) | |
| put_app() | |
| app_restart() | |
| add_ec2_to_elb() | |
| run('sleep %s' % SLEEP_TIME) |
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| $ fab -H 52.197.196.202,52.197.152.24 -f deploy all | |
| [52.197.196.202] Executing task 'all' | |
| [52.197.196.202] run: curl http://169.254.169.254/latest/meta-data/instance-id | |
| [52.197.196.202] out: i-1096ad9f | |
| => Removed i-1096ad9f from my-elb | |
| [52.197.196.202] run: sleep 20 | |
| [52.197.196.202] put: /Users/yako/Desktop/myapp/aaaa.txt -> /usr/local/src/myapp/aaaa.txt | |
| [52.197.196.202] put: /Users/yako/Desktop/myapp/bbbb.txt -> /usr/local/src/myapp/bbbb.txt | |
| [52.197.196.202] sudo: service myapp restart | |
| [52.197.196.202] out: Stopping myapp: [ OK ] | |
| [52.197.196.202] out: | |
| [52.197.196.202] out: Starting myapp: [ OK ] | |
| [52.197.196.202] out: | |
| [52.197.196.202] out: | |
| [52.197.196.202] run: curl http://169.254.169.254/latest/meta-data/instance-id | |
| [52.197.196.202] out: i-1096ad9f | |
| => Add i-1096ad9f to my-elb | |
| [52.197.196.202] run: sleep 20 | |
| [52.197.152.24] Executing task 'all' | |
| [52.197.152.24] run: curl http://169.254.169.254/latest/meta-data/instance-id | |
| [52.197.152.24] out: i-1296ad9d | |
| => Removed i-1296ad9d from my-elb | |
| [52.197.152.24] run: sleep 20 | |
| [52.197.152.24] put: /Users/yako/Desktop/myapp/aaaa.txt -> /usr/local/src/myapp/aaaa.txt | |
| [52.197.152.24] put: /Users/yako/Desktop/myapp/bbbb.txt -> /usr/local/src/myapp/bbbb.txt | |
| [52.197.152.24] sudo: service myapp restart | |
| [52.197.152.24] out: Stopping myapp: [ OK ] | |
| [52.197.152.24] out: | |
| [52.197.152.24] out: Starting myapp: [ OK ] | |
| [52.197.152.24] out: | |
| [52.197.152.24] out: | |
| [52.197.152.24] run: curl http://169.254.169.254/latest/meta-data/instance-id | |
| [52.197.152.24] out: i-1296ad9d | |
| => Add i-1296ad9d to my-elb | |
| [52.197.152.24] run: sleep 20 | |
| Done. | |
| Disconnecting from 52.197.196.202... done. | |
| Disconnecting from 52.197.152.24... done. |
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