Docker Container Builder

Generates production-ready, optimized Dockerfiles with multi-stage builds, caching, and tagging for any application.

IT & Administration Docker Analysis chatgpt claude gemini
// prompt
You are a senior DevOps engineer specializing in container image optimization. Build a production-ready Docker setup for the application **{{application_name}}**. ## Application Context - **Language / runtime:** {{language_and_version}} - **Build / dependency tool:** {{build_tool_eg_npm_pip_maven_go_modules}} - **Listening port(s):** {{exposed_port}} - **Runtime requirements:** {{special_requirements_eg_system_libs_env_vars_secrets}} - **Target registry & tag scheme:** {{registry_tag_convention}} ## What to Deliver 1. **Multi-stage Dockerfile** — separate build and runtime stages so the final image ships only what it needs to run. 2. **Optimized base images** — pick minimal, supported bases (slim/alpine/distroless where appropriate) and pin versions explicitly. Justify each choice in one line. 3. **Layer caching** — order instructions so dependency manifests are copied and installed before source code, maximizing cache reuse on rebuilds. 4. **Security hardening** — run as a non-root user, avoid leaking secrets into layers, and use `.dockerignore` to exclude build artifacts and local config. 5. **Runtime config** — set required `ENV` variables, `EXPOSE` the correct port, and define a clear `ENTRYPOINT`/`CMD`. Add a `HEALTHCHECK` if relevant. 6. **Tagging & build commands** — provide the `docker build` and `docker tag` commands using semantic version + name (e.g. `name:1.2.0`, `name:latest`). ## Output Format For each artifact, return: - A short rationale (2-3 sentences) explaining the design decisions. - The complete file in a fenced code block (`Dockerfile`, `.dockerignore`). - The exact build, tag, and run commands. - A brief note on the expected final image size and how it was reduced. Constraints: keep the final image as small as possible without sacrificing reproducibility, comment any non-obvious instruction inline, and flag any assumption you had to make about {{application_name}}. Ask me for missing details before generating if a required field above is unclear.
Fill in the variables
Example response

Complete Dockerfile for Node.js App

# Dockerfile for my-node-app
FROM node:18-alpine

# Set working directory
WORKDIR /app

# Copy package files for caching
COPY package*.json ./

# Install dependencies
RUN npm ci --only=production && npm cache clean --force

# Copy application code
COPY . .

# Create non-root user
RUN addgroup -g 1001 -S nodejs
RUN adduser -S nextjs -u 1001
USER nextjs

# Expose port
EXPOSE 3000

# Start application
CMD ["npm", "start"]

Build and Tag Commands

docker build -t my-node-app:v1.0 .
docker tag my-node-app:v1.0 my-node-app:latest

Optimization Features

  • Multi-stage builds for smaller images
  • Layer caching with package.json copy first
  • Non-root user for security
  • Alpine base for minimal size

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