deployment-cicdlisted

# Deployment + CI/CD — Ship Safely, Roll Back Fast A practical playbook for the deploy pipeline that gets a feature from "merged" to "in production" reliably. Stack-agnostic core; recipes assume Docker + GitHub Actions + Kubernetes (the 2026 industry default) with callouts for AWS / GCP / Fly.io specifics. ## When to Use This Skill - Designing CI for a new service — the shape now sets the team's culture. - Writing or auditing a Dockerfile — bad layers cost minutes per build. - Choosing between rolling, blue-green, canary, or feature-flag deploys. - Defining the release process — who clicks deploy, when, and what's reversible. - Adding semantic versioning + automated changelogs. - Setting up secrets in CI without leaking them. - Writing a rollback playbook (preferably *before* you need it). - Migrating manual deploys → GitOps (Argo CD / Flux). Skip when: prototyping a script. Real services, real pipelines. ## The Deployment Pipeline — Six Stages ``` commit → build → test → image → deploy(staging) → deploy(prod) │ │ │ │ │ │ <1s 1-3m 1-5m 1-2m 1-5m 1-5m + verify ``` Every stage must be: - **Idempotent** — re-running produces the same result. - **Fast-failing** — break early, don't ship to staging if unit tests failed. - **Observable** — emit deploy markers to metrics so dashboards correlate "the spike" with "the deploy". - **Reversible** — every forward step has a documented backward step. **Hard tar