mcpbeat

Bun Docker

secondsky/bun-docker

Use for Docker with Bun, Dockerfiles, oven/bun image, containerization, and deployments.

2k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
202
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/secondsky/claude-skills --skill bun-docker

The instruction itself

19 sections, as written by the author

Bun Docker

Deploy Bun applications in Docker containers using official images.

Official Images

# Latest stable
docker pull oven/bun

# Specific version
docker pull oven/bun:1.0.0

# Variants
oven/bun:latest       # Full image (~100MB)
oven/bun:slim         # Minimal image (~80MB)
oven/bun:alpine       # Alpine-based (~50MB)
oven/bun:distroless   # Distroless (~60MB)
oven/bun:debian       # Debian-based (~100MB)

Basic Dockerfile

FROM oven/bun:1 AS base

WORKDIR /app

# Install dependencies
COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile

# Copy source
COPY . .

# Run
EXPOSE 3000
CMD ["bun", "run", "src/index.ts"]

Multi-Stage Build (Production)

# Build stage
FROM oven/bun:1 AS builder

WORKDIR /app

COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile

COPY . .
RUN bun run build

# Production stage
FROM oven/bun:1-slim AS production

WORKDIR /app

# Copy only production dependencies
COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile --production

# Copy built assets
COPY --from=builder /app/dist ./dist

# Run as non-root
USER bun

EXPOSE 3000
CMD ["bun", "run", "dist/index.js"]

Alpine Image

FROM oven/bun:1-alpine

WORKDIR /app

# Alpine uses apk for packages
RUN apk add --no-cache git

COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile

COPY . .

CMD ["bun", "run", "src/index.ts"]

Distroless Image

# Build stage
FROM oven/bun:1 AS builder

WORKDIR /app
COPY . .
RUN bun install --frozen-lockfile
RUN bun build src/index.ts --compile --outfile=app

# Runtime stage
FROM gcr.io/distroless/base

COPY --from=builder /app/app /app

ENTRYPOINT ["/app"]

Docker Compose

# docker-compose.yml
version: "3.8"

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - NODE_ENV=production
      - DATABASE_URL=postgres://db:5432/app
    depends_on:
      - db
    restart: unless-stopped

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_DB: app
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
    volumes:
      - postgres_data:/var/lib/postgresql/data

volumes:
  postgres_data:

Hot Reload in Development

# docker-compose.dev.yml
version: "3.8"

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile.dev
    ports:
      - "3000:3000"
    volumes:
      - ./src:/app/src
      - ./package.json:/app/package.json
    command: bun --hot run src/index.ts
# Dockerfile.dev
FROM oven/bun:1

WORKDIR /app

COPY package.json bun.lockb ./
RUN bun install

# Source mounted as volume
CMD ["bun", "--hot", "run", "src/index.ts"]

Compiled Binary

FROM oven/bun:1 AS builder

WORKDIR /app
COPY . .
RUN bun install --frozen-lockfile
RUN bun build src/index.ts --compile --outfile=server

# Minimal runtime
FROM ubuntu:22.04

# Install runtime dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    ca-certificates \
    && rm -rf /var/lib/apt/lists/*

COPY --from=builder /app/server /usr/local/bin/server

USER nobody
EXPOSE 3000
CMD ["server"]

SQLite with Docker

FROM oven/bun:1

WORKDIR /app

COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile

COPY . .

# Create data directory
RUN mkdir -p /app/data

# Volume for SQLite database
VOLUME /app/data

ENV DATABASE_PATH=/app/data/app.sqlite

CMD ["bun", "run", "src/index.ts"]

Health Checks

FROM oven/bun:1

WORKDIR /app
COPY . .
RUN bun install --frozen-lockfile

EXPOSE 3000

HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
  CMD curl -f http://localhost:3000/health || exit 1

CMD ["bun", "run", "src/index.ts"]
// Health endpoint
app.get("/health", (c) => c.json({ status: "ok" }));

Environment Variables

FROM oven/bun:1

WORKDIR /app

# Build-time args
ARG NODE_ENV=production
ARG API_URL

# Runtime env
ENV NODE_ENV=${NODE_ENV}
ENV API_URL=${API_URL}

COPY . .
RUN bun install --frozen-lockfile

CMD ["bun", "run", "src/index.ts"]
# Build with args
docker build --build-arg API_URL=https://api.example.com -t myapp .

# Run with env
docker run -e DATABASE_URL=postgres://... myapp

Caching Optimization

FROM oven/bun:1 AS base

WORKDIR /app

# Cache dependencies separately
FROM base AS deps
COPY package.json bun.lockb ./
RUN bun install --frozen-lockfile

# Build
FROM deps AS builder
COPY . .
RUN bun run build

# Production
FROM base AS runner
COPY --from=deps /app/node_modules ./node_modules
COPY --from=builder /app/dist ./dist
COPY package.json ./

USER bun
CMD ["bun", "run", "dist/index.js"]

Secure Installation

When installing packages in Docker builds, follow supply chain security best practices:

  • Block post-install scripts — Bun disables them by default; allow specific packages via trustedDependencies
  • Pin dependency versions — Use exact versions in package.json for reproducible builds
  • Audit before installing — Run socket package score npm <pkg> to check packages before they reach your image

Load the dependency-upgrade skill for full security configuration including Socket CLI integration, cooldown setup, lockfile validation, and CI enforcement.

Security Best Practices

FROM oven/bun:1-slim

WORKDIR /app

# Don't run as root
USER bun

# Copy with correct ownership
COPY --chown=bun:bun package.json bun.lockb ./
RUN bun install --frozen-lockfile --production

COPY --chown=bun:bun . .

# Read-only filesystem
# (use with: docker run --read-only)

EXPOSE 3000
CMD ["bun", "run", "src/index.ts"]

.dockerignore

node_modules
.git
.gitignore
*.md
Dockerfile*
docker-compose*
.env*
.DS_Store
coverage
dist
.bun

Common Commands

# Build
docker build -t myapp .

# Run
docker run -p 3000:3000 myapp

# Run with env file
docker run --env-file .env -p 3000:3000 myapp

# Interactive shell
docker run -it oven/bun sh

# Check Bun version
docker run oven/bun bun --version

Common Errors

| Error | Cause | Fix |

|-------|-------|-----|

| bun.lockb not found | Missing lockfile | Run bun install locally |

| EACCES permission | File ownership | Use --chown=bun:bun |

| OOM killed | Memory limit | Increase container memory |

| No space left | Large layers | Use multi-stage builds |

When to Load References

Load references/optimization.md when:

  • Image size reduction
  • Layer caching
  • Build performance

Load references/kubernetes.md when:

  • K8s deployment
  • Horizontal scaling
  • Service mesh

How to use it

Copy the folder

Take secondsky/bun-docker from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.

Install what it needs

The instructions reference apt, docker. Without those the skill loads but fails at the first command.