AWS Elastic BeanstalkでLinuxアプリをデプロイする方法｜環境設定とローリングデプロイ・マルチAZ・VPC統合の設計パターン入門

この記事のポイント

・eb init → eb create の2ステップで環境が作成できる
・ローリングデプロイは .ebextensions/deploy.config の DeploymentPolicy で制御する
・マルチAZ構成は Availability Zones と MinSize を組み合わせて設計する
・VPC統合は eb create --vpc.id / --vpc.ec2subnets / --vpc.elbsubnets で指定する

# Python 3がインストール済みであることを前提とする
$ pip3 install awsebcli --upgrade

$ eb --version
EB CLI 3.21.0 (Python 3.11.4)

$ eb init

Select a default region
1) us-east-1 : US East (N. Virginia)
...
11) ap-northeast-1 : Asia Pacific (Tokyo)
(default is 3): 11

Enter Application Name
(default is "myapp"): my-linux-app
Application my-linux-app has been created.

Select a platform.
1) .NET Core on Linux
2) Docker
3) Go
4) Node.js
5) PHP
6) Python
...
(make a selection): 6

Select a platform branch.
1) Python 3.11 running on 64bit Amazon Linux 2023
2) Python 3.9 running on 64bit Amazon Linux 2023
(default is 1): 1

$ eb create my-env \
  --region ap-northeast-1 \
  --elb-type application \
  --instance-types t3.small

Creating application version archive "app-v1.0".
Uploading my-linux-app/app-v1.0.zip to S3. This may take a while.
Upload Complete.
Environment details for: my-env
  Application name: my-linux-app
  Region: ap-northeast-1
  Deployed Version: app-v1.0
  Environment ID: e-xxxxxxxxxxxx
  Platform: Python 3.11 running on 64bit Amazon Linux 2023/4.0.8
  Tier: WebServer-Standard-1.0
  CNAME: my-env.eba-xxxxxxxxxx.ap-northeast-1.elasticbeanstalk.com
2026-09-19 06:28:15    INFO    Successfully launched environment: my-env

$ eb status my-env
Environment details for: my-env
  Application name: my-linux-app
  Region: ap-northeast-1
  CNAME: my-env.eba-xxxxxxxxxx.ap-northeast-1.elasticbeanstalk.com
  Updated: 2026-09-19 06:28:15.000000+00:00
  Status: Ready
  Health: Green

# .ebextensions/deploy.config
option_settings:
  aws:elasticbeanstalk:command:
    DeploymentPolicy: Rolling
    BatchSizeType: Percentage
    BatchSize: "30"
    MinInstancesInService: 1

# Greenの環境（v2）を作成
$ eb create my-env-green \
  --region ap-northeast-1 \
  --elb-type application \
  --instance-types t3.small

# Green環境へデプロイして動作確認後、CNAMEをBlueとSwap
$ eb swap my-env --destination_name my-env-green

# .ebextensions/autoscaling.config
option_settings:
  aws:autoscaling:asg:
    MinSize: 2
    MaxSize: 4
    Availability Zones: Any 2
  aws:autoscaling:trigger:
    MeasureName: CPUUtilization
    Unit: Percent
    UpperThreshold: 70
    LowerThreshold: 30
    UpperBreachScaleIncrement: 1
    LowerBreachScaleIncrement: -1

option_settings:
  aws:elasticbeanstalk:environment:process:default:
    HealthCheckPath: /health
    HealthCheckInterval: 30
    HealthyThresholdCount: 3
    UnhealthyThresholdCount: 5

$ eb create my-env-prod \
  --vpc.id vpc-0a1b2c3d4e5f6a7b8 \
  --vpc.ec2subnets subnet-priv-1a,subnet-priv-1c \
  --vpc.elbsubnets subnet-pub-1a,subnet-pub-1c \
  --vpc.elbpublic \
  --vpc.publicip false \
  --elb-type application \
  --instance-types t3.medium \
  --region ap-northeast-1

# .ebextensions/securitygroups.config
option_settings:
  aws:autoscaling:launchconfiguration:
    SecurityGroups: sg-ec2-for-beanstalk
  aws:elbv2:loadbalancer:
    SecurityGroups: sg-alb-for-beanstalk

option_settings:
  aws:autoscaling:launchconfiguration:
    ImageId: ami-0abc1234567890def

$ eb platform list --region ap-northeast-1 2>&1 | grep "Python 3.11"
arn:aws:elasticbeanstalk:ap-northeast-1::platform/Python 3.11 running on 64bit Amazon Linux 2023/4.0.8

$ eb logs my-env

============= i-0a1b2c3d4e5f6a7b8 ==============

/var/log/eb-engine.log
-----
[2026-09-19T06:32:00.000Z] INFO    [PID 1234] - Executing deployment script.
[2026-09-19T06:32:15.000Z] ERROR   [PID 1234] - Command failed: /var/app/staging/.platform/hooks/prebuild/01_setup.sh
[2026-09-19T06:32:15.000Z] ERROR   [PID 1234] - Error: command failed with exit code 1

/var/log/web.stdout.log
-----
ModuleNotFoundError: No module named 'requests'

$ eb health my-env --refresh
 id             status    cause
──────────────────────────────────────────────────────────────────
i-0a1b2c3d4e5f  Ok        -
i-0f9e8d7c6b5a  Ok        -