Git, Docker, and CI/CD Foundations

Every software team, whatever it builds, needs the same three habits: a truthful history of the code, a repeatable way to run it anywhere, and a release process that fails safely. This course builds those habits on one small HTTP status service that you create in the first lesson and ship in the last one. **Git (lessons 1–4).** You initialise a repository, learn the three areas (working tree, staging area, repository), branch and merge, resolve a real conflict, publish to a shared origin, run a feature-branch review workflow with a second working copy, and undo mistakes with `restore`, `reset`, `revert`, the reflog and `stash` — choosing the right tool for local versus shared history. **Docker (lessons 5–7).** You run, inspect and clean up containers, write a Dockerfile for the service with a non-root user and a built-in health check, learn how layers and the build cache behave, and define a Compose stack with PostgreSQL 16, a persistent volume and a git-ignored environment file. **CI/CD and operations (lessons 8–10).** You write `ci.sh` — lint, test, build, smoke-test, tag — as a contract that exits non-zero on the first failure, run it automatically from a versioned pre-push hook, and read the same contract expressed as a GitHub Actions workflow. You then cut `v1.0.0` and `v1.0.1` releases, promote the tested image without rebuilding, roll the service back and forward, and finish with logs, restart policies, resource limits, secrets handling, image-scanning concepts and disk hygiene. **Final project.** "Ship the service": from an empty directory you deliver a versioned repository with a feature-branch history, a Dockerfile, a Compose stack, a passing `ci.sh`, two releases, a demonstrated rollback and a short runbook — graded against a rubric and automated lab checks. Everything runs on your own lab machine `linux01`. No GitHub or GitLab account is needed: the remote is a local bare repository and CI is a script you can read in full. The course is a learning pathway toward software-delivery and platform work; it does not promise employment or any vendor certification.