Dockerfile

Dockerfile Generator

Analyze the current project and generate an optimized, production-ready, multi-stage Dockerfile.

Process

1. Detect project stack by scanning for manifest files:

• package.json / yarn.lock / pnpm-lock.yaml -> Node.js
• pom.xml / build.gradle -> Java (Maven/Gradle)
• requirements.txt / pyproject.toml / Pipfile -> Python
• go.mod -> Go
• Cargo.toml -> Rust
• Gemfile -> Ruby
• pubspec.yaml -> Dart/Flutter
• *.csproj / *.sln -> .NET

1. Detect framework from dependencies:

• Express, Next.js, Nest.js, Fastify (Node)
• Spring Boot, Quarkus (Java)
• Django, Flask, FastAPI (Python)
• Gin, Echo, Fiber (Go)

1. Read project config for:

• Entry point / main file
• Build commands
• Port numbers
• Environment variable requirements

1. Generate Dockerfile following best practices.

1. Generate .dockerignore if it doesn't exist.

Best Practices to Follow

Always

• Use multi-stage builds (builder + runtime)
• Use specific version tags for base images (not latest)
• Use slim/alpine base images for runtime
• Run as non-root user in production stage
• Set WORKDIR explicitly
• Copy dependency files first, install, then copy source (layer caching)
• Use COPY not ADD (unless extracting archives)
• Set ENV NODE_ENV=production or equivalent
• Include HEALTHCHECK instruction
• Use .dockerignore to exclude unnecessary files

Never

• Install dev dependencies in the runtime image
• Leave package manager caches in the final image
• Use root user in the final stage
• Hardcode secrets or credentials
• Use latest tag for base images

Templates by Stack

Node.js

FROM node:-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:-alpine
RUN addgroup -S appgroup && adduser -S appuser -G appgroup
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
COPY package*.json ./
USER appuser
EXPOSE 
HEALTHCHECK CMD wget -q --spider http://localhost:/health || exit 1
CMD ["node", "dist/index.js"]

Java (Spring Boot)

FROM eclipse-temurin:-jdk-alpine AS builder
WORKDIR /app
COPY pom.xml mvnw ./
COPY .mvn .mvn
RUN ./mvnw dependency:resolve
COPY src ./src
RUN ./mvnw package -DskipTests

FROM eclipse-temurin:-jre-alpine
RUN addgroup -S appgroup && adduser -S appuser -G appgroup
WORKDIR /app
COPY --from=builder /app/target/*.jar app.jar
USER appuser
EXPOSE 
HEALTHCHECK CMD wget -q --spider http://localhost:/actuator/health || exit 1
ENTRYPOINT ["java", "-jar", "app.jar"]

Python

FROM python:-slim AS builder
WORKDIR /app
COPY requirements.txt .
RUN pip install --no-cache-dir --prefix=/install -r requirements.txt

FROM python:-slim
RUN useradd -m -r appuser
WORKDIR /app
COPY --from=builder /install /usr/local
COPY . .
USER appuser
EXPOSE 
HEALTHCHECK CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:/health')" || exit 1
CMD ["python", "app.py"]

Go

FROM golang:-alpine AS builder
WORKDIR /app
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o server .

FROM alpine:3.19
RUN addgroup -S appgroup && adduser -S appuser -G appgroup
WORKDIR /app
COPY --from=builder /app/server .
USER appuser
EXPOSE 
HEALTHCHECK CMD wget -q --spider http://localhost:/health || exit 1
CMD ["./server"]

Output

1. Write the Dockerfile to the project root.
2. Write .dockerignore if it doesn't exist.
3. Print a summary: detected stack, base image chosen, exposed port, and build/run commands:

`` docker build -t . docker run -p : ``

Notes

• If $ARGUMENTS contains a framework hint (e.g., "nextjs", "spring"), use that to guide detection.
• If multiple stacks detected (monorepo), ask the user which service to dockerize.
• Always read the existing Dockerfile first if one exists — offer to improve it rather than overwrite.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: pulkit0x
• Source: pulkit0x/claude-armory
• License: MIT

Install and usage instructions live in the source repository linked above.