DEVOPS / A CONCEPT NOTE
CI/CD
automated pipelines that build, test, and deploy every change
Overview · mechanism
pitfall · examples
01 / THE SHORT VERSION
The idea in a few sentences.
Every time you push code, a CI server (GitHub Actions, GitLab CI, Jenkins) automatically runs tests, linters, and builds. If everything passes, CD deploys the artifact to staging or production — no manual steps. The pipeline is defined in YAML in your repo, versioned alongside your code.
02 / FOLLOW THE MECHANISM
How a CI/CD pipeline runs
Push
a developer pushes code to a branch on GitHub/GitLab.
Webhook
triggers the CI server with the commit SHA and branch name.
CI runner
spins up a clean environment (container or VM), checks out the code, and runs the pipeline steps sequentially.
Jobs
run in parallel or serial — lint → unit test → build → integration test → security scan.
CD deploy
if all jobs pass on main, the pipeline promotes the artifact: Docker image push, Helm upgrade, or Terraform apply.
04 / COMMAND NOTES
Read the command, then the result.
Inspect the flags and arguments before trying an example. Snippets can need local setup, replacement values, or resources in your own environment.
list recent GitHub Actions runs
gh run list --limit 10list GitHub Actions jobs locally with act
act --list05 / CHECK YOURSELF
Could you explain CI/CD to a teammate?
Try it out loud in two sentences: what it is, and the one detail that changes the picture. If you stall, the gap is the part to reread.
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