Rails开发容器未安装Ruby和Bundler启动报错求助

问题现象 #

启动容器时出现以下错误：

[2025-03-19T16:39:10.740Z] Error response from daemon: failed to create task for container: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: exec: "bundle": executable file not found in $PATH: unknown

进入容器后执行相关命令，发现Ruby、Gem、Bundler命令均不存在：

root ➜ / $ bundle
bash: bundle: command not found
root ➜ / $ gem
bash: gem: command not found
root ➜ / $ ruby
bash: ruby: command not found

配置文件 #

Dockerfile #

ARG RUBY_VERSION=3.4.2
FROM ghcr.io/rails/devcontainer/images/ruby:$RUBY_VERSION

# Install packages needed to build gems
RUN apt-get update -qq \
    && apt-get install --no-install-recommends -y \
    build-essential \
    libpq-dev \
    libvips \
    curl \
    imagemagick \
    postgresql-client \
    nodejs \
    vim \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*

compose.yml #

name: "escrow_safe"
services:
  web:
    build:
      dockerfile: .devcontainer/Dockerfile
      context: ..
    ports:
      - "3000:3000"
      - "12345:12345"
    command: sleep infinity
    environment:
      - ES_DEV_PHONE_OVERRIDE
      - DEV_EMAIL_PREFIX=${USER}
      - DATABASE_URL=postgres://root:password@postgres-db/
      - EDITOR=vim
      - ES_DEBUG_ENABLED=true
    volumes:
      - ../..:/workspaces:cached
    depends_on:
      postgres-db:
        condition: service_healthy

  solidq:
    build:
      dockerfile: .devcontainer/Dockerfile
      context: ..
    command: bundle exec rails solid_queue:start
    environment:
      - DATABASE_URL=postgres-db://root:password@postgres-db/
    volumes:
      - ../..:/workspaces:cached
      # - bundler_gems:/usr/local/bundle
    depends_on:
      postgres-db:
        condition: service_healthy

  postgres-db:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: root
      POSTGRES_PASSWORD: password
    volumes:
      - db_data:/var/lib/postgresql/data
    ports:
      - "5432:5432"
    healthcheck:
      test: pg_isready
      interval: 2s
      timeout: 5s
      retries: 30

volumes:
  db_data:

devcontainer.json #

{
  "name": "escrow_safe",
  "dockerComposeFile": "compose.yaml",
  "service": "web",
  // "workspaceFolder": "/rails",
  "workspaceFolder": "/workspaces/${localWorkspaceFolderBasename}",
  // Features to add to the dev container.
  "features": {
    "ghcr.io/devcontainers/features/github-cli:1": {},
    "ghcr.io/rails/devcontainer/features/activestorage": {},
    "ghcr.io/rails/devcontainer/features/postgres-client": {},
    "ghcr.io/rails/devcontainer/features/bundler-cache:1": {}
  },
  "containerEnv": {
    "CAPYBARA_SERVER_PORT": "45678",
    "SELENIUM_HOST": "selenium",
    "DB_HOST": "postgres"
  },
  // Use 'forwardPorts' to make a list of ports inside the container available locally.
  "forwardPorts": [
    3000,
    5432,
    6379
  ],
  // Configure tool-specific properties.
  // "customizations": {},
  // Uncomment to connect as root instead.
  // "remoteUser": "root",
  // Use 'postCreateCommand' to run commands after the container is created.
  "postCreateCommand": "bin/setup"
}

解决办法 #

1. 验证基础镜像完整性
   直接拉取并运行指定的Ruby基础镜像，确认Ruby是否内置：

docker run --rm -it ghcr.io/rails/devcontainer/images/ruby:3.4.2 ruby -v

若返回Ruby版本信息说明镜像正常；若报错，重新拉取镜像或检查版本号是否正确。

2. 排查镜像构建问题
   手动执行镜像构建命令，查看过程是否有异常：

# 从项目根目录执行
docker build -t rails-dev-test .devcontainer/

构建完成后运行测试容器检查Ruby命令：

docker run --rm -it rails-dev-test ruby -v

若此处正常，清理旧镜像后重新启动compose：

docker compose down --rmi all
docker compose up -d

3. 排除挂载目录影响
   暂时注释掉compose.yml中web服务的volumes配置，重启容器后检查Ruby命令是否存在。若恢复正常，说明本地挂载可能意外覆盖了容器内关键路径。

4. 排查devcontainer特性冲突
   暂时注释掉devcontainer.json中的bundler-cache特性，重新构建容器。部分特性可能修改Ruby环境或PATH变量导致命令丢失。

5. 确认用户权限与PATH设置
   devcontainer默认使用非root用户（如vscode或rails），避免用root执行命令。若必须用root，需将非root用户的Ruby路径添加到PATH：

# 示例：假设Ruby安装在/home/rails/.rbenv/shims
export PATH="/home/rails/.rbenv/shims:$PATH"

也可在devcontainer.json中取消注释"remoteUser": "root"，确保基础镜像中Ruby安装在全局路径（如/usr/local/bin）。

内容的提问来源于stack exchange，提问作者James Klein