dynamodb-local-proxy

Motivation

dynamodb-local-proxy is a lightweight HTTP proxy for DynamoDB Local that automatically supplements the DescribeTable API response with the missing WarmThroughput field.

It solves the compatibility issue where terraform-provider-aws v6.13+ (and potentially other modern clients) now expect WarmThroughput in DescribeTable output¹. DynamoDB Local (up to 3.3.0) does not return this field, causing Terraform to hang indefinitely waiting for table creation and eventually time out.

By sitting in front of DynamoDB Local and injecting a dummy WarmThroughput value only for DescribeTable calls, the proxy makes DynamoDB Local fully compatible with the latest Terraform AWS provider without changing any application code.

詳しくは TerraformでDynamoDB localのテーブルを作成しようとするとタイムアウトする現象 - 私が歌川です を読んでください。

Environment Variables

Variable	Default	Description
DYNAMODB_LOCAL_ADDR	localhost:8000	Address of DynamoDB Local to proxy requests to
HOST	localhost	Host address the proxy listens on
PORT	8888	Port the proxy listens on
LOG_LEVEL	INFO	Log level (DEBUG, INFO, WARN, ERROR)

Usage

With AWS CLI

You can get patched response by executing aws --endpoint-url=http://localhost:8888 dynamodb describe-table --table-name <table-name>.

Run with Docker Compose

services:
  dynamodb-local:
    command: -jar DynamoDBLocal.jar -sharedDb -dbPath ./data
    image: amazon/dynamodb-local
    volumes:
      - "./docker/dynamodb:/home/dynamodblocal/data"
    working_dir: /home/dynamodblocal
  dynamodb-local-proxy:
    image: ghcr.io/utgwkk/dynamodb-local-proxy
    environment:
      - DYNAMODB_LOCAL_ADDR=dynamodb-local:8000
      - HOST=0.0.0.0
      - PORT=8888
    ports:
      - "8888:8888"

Run with GitHub Actions

Using Docker Compose's bridge network mode with GitHub Actions can be slow, so I recommend starting it using the services method in GitHub Actions workflows.

on:
  push:
    branches:
      - main
  pull_request:
jobs:
  test:
    runs-on: ubuntu-latest
    services:
      dynamodb-local:
        image: amazon/dynamodb-local
      dynamodb-local-proxy:
        image: ghcr.io/utgwkk/dynamodb-local-proxy
        env:
          DYNAMODB_LOCAL_ADDR: dynamodb-local:8000
          HOST: 0.0.0.0
          PORT: 8888
        ports:
          - 8888:8888
    steps:
      - run: aws --endpoint-url=http://localhost:8888 dynamodb list-tables

Footnotes

1. https://github.com/hashicorp/terraform-provider-aws/pull/41308 ↩