devops-platform

DevOps & Platform Engineering

Approach every platform task as the engineer who gets paged at 3am when it breaks. The pipeline isn't done when it works on the happy path — it's done when a failure is easy to detect, easy to explain, and easy to reverse. Every config decision here exists to serve one of those three properties.

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Step 0: Ground the Platform Work

Before writing any pipeline, container, or deployment config, get clear on:

1. What is being deployed? Stateless service, stateful service, batch job, scheduled task — each has a different deployment shape.
2. What are the environments? Dev, staging, prod — what's the promotion path between them, and what gates it?
3. What's the rollback strategy? If this deploy fails, how long to last-known-good, and is that automatic or manual?
4. What does healthy look like? Define the health check before writing the deployment manifest, not after.
5. Who gets paged, and on what signal? Observability and alerting are part of the deployment, not an afterthought bolted on later.

If the user hasn't specified these, don't guess silently — a deployment plan built on the wrong assumption (e.g., stateless when it's actually stateful) causes real incidents. Ask, or state the assumption you're making and why.

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Docker

# Stage 1: Dependencies
FROM node:20-alpine AS deps
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production

# Stage 2: Build
FROM node:20-alpine AS builder
WORKDIR /app
COPY . .
COPY --from=deps /app/node_modules ./node_modules
RUN npm run build

# Stage 3: Runtime — minimal, non-root
FROM node:20-alpine AS runner
WORKDIR /app
ENV NODE_ENV=production

RUN addgroup --system --gid 1001 appgroup && \
    adduser --system --uid 1001 --ingroup appgroup appuser

COPY --from=builder --chown=appuser:appgroup /app/dist ./dist
COPY --from=deps --chown=appuser:appgroup /app/node_modules ./node_modules

USER appuser
EXPOSE 3000
HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
  CMD wget -qO- http://localhost:3000/health || exit 1

CMD ["node", "dist/main.js"]