devops-infrastructure

DevOps & Infrastructure

When to Load

• Trigger: Docker, CI/CD pipelines, deployment configuration, monitoring, infrastructure as code
• Skip: Application logic only with no infrastructure or deployment concerns

DevOps Workflow

Copy this checklist and track progress:

DevOps Setup Progress:
- [ ] Step 1: Containerize application (Dockerfile)
- [ ] Step 2: Set up CI/CD pipeline
- [ ] Step 3: Define deployment strategy
- [ ] Step 4: Configure monitoring & alerting
- [ ] Step 5: Set up environment management
- [ ] Step 6: Document runbooks
- [ ] Step 7: Validate against anti-patterns checklist

Docker Best Practices

Multi-Stage Build

# WRONG: Single stage, bloated image
FROM node:20
WORKDIR /app
COPY . .
RUN npm install
RUN npm run build
CMD ["node", "dist/index.js"]
# Result: 1.2GB image with devDependencies and source code

# CORRECT: Multi-stage build
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build

FROM node:20-alpine AS runner
WORKDIR /app
ENV NODE_ENV=production
RUN addgroup -g 1001 appgroup && adduser -u 1001 -G appgroup -s /bin/sh -D appuser
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
COPY --from=builder /app/package.json ./
USER appuser
EXPOSE 3000
CMD ["node", "dist/index.js"]
# Result: ~150MB image, no devDependencies, non-root user

Python Multi-Stage

FROM python:3.12-slim AS builder
WORKDIR /app
RUN pip install uv
COPY pyproject.toml uv.lock ./
RUN uv sync --frozen --no-dev
COPY . .

FROM python:3.12-slim AS runner
WORKDIR /app
RUN useradd -r -s /bin/false appuser
COPY --from=builder /app/.venv /app/.venv
COPY --from=builder /app/src ./src
ENV PATH="/app/.venv/bin:$PATH"
USER appuser
CMD ["python", "-m", "src.main"]

Layer Caching

# WRONG: Cache busted on every code change
COPY . .
RUN npm ci

# CORRECT: Dependencies cached separately
COPY package*.json ./
RUN npm ci                  # cached unless package.json changes
COPY . .                    # only source code changes bust this layer