フォルダ構成

tree

├── docker-compose.yml
└── localstack
    └── init_s3.sh

docker-compose

volumes で ./localstack を /docker-entrypoint-initaws.d へ割り当てる
これにより ./localstack/*.sh が docker-compose up 時に実行される

docker-compose.yml

services:
  localstack:
    container_name: "${LOCALSTACK_DOCKER_NAME-localstack_main}"
    image: localstack/localstack
    network_mode: bridge
    ports:
      - "4566:4566"
      - "4571:4571"
      - "${PORT_WEB_UI-8080}:${PORT_WEB_UI-8080}"
    environment:
      - SERVICES=${SERVICES- }
      - DEBUG=${DEBUG- }
      - DATA_DIR=${DATA_DIR- }
      - PORT_WEB_UI=${PORT_WEB_UI- }
      - LAMBDA_EXECUTOR=${LAMBDA_EXECUTOR- }
      - KINESIS_ERROR_PROBABILITY=${KINESIS_ERROR_PROBABILITY- }
      - DOCKER_HOST=unix:///var/run/docker.sock
      - HOST_TMP_FOLDER=${TMPDIR}
    volumes:
      - ./localstack:/docker-entrypoint-initaws.d # ここ

shell

./localstack/init_s3.sh にバケット作成コマンド

init_s3.sh

#!/bin/bash
awslocal s3 mb s3://hoget

おわり

参考
- localstack/localstack - GitHub