Pipelines, deployment strategies and release safety.
6 items at beginner level · all topics
Compare blue-green, canary, and rolling deployments. When would you choose each?
Rolling replaces instances gradually, blue-green switches all traffic between two full environments at once, and canary sends a small slice of real traffic to the new version while watching metrics. They differ mainly in rollback speed, cost, and how much confidence you gain before full exposure.
Code works on the developer's machine but fails in Jenkins. How could Git be involved?
Stop guessing about the code and compare commit SHAs first. CI often builds a different commit than the developer tested: a merge commit, a stale workspace, a shallow clone, missing submodules, or a file that's gitignored locally but needed at build time. Only once the SHAs match is it worth looking at the code.
A developer started a feature branch from an outdated main. How would you fix it?
Fetch, then rebase the branch onto origin/main so the work replays on current code. Rebase is right while the branch is private; if it's been pushed and others use it, merge main in instead so you don't rewrite shared SHAs.
A Git repository has become huge and cloning takes 20 minutes. What would you investigate?
Measure before you guess. Find the biggest objects in history, because size usually comes from binaries and build artifacts committed long ago. Deleting them today does nothing: the old blobs stay in history until you rewrite it or route developers around downloading them in the first place.
A Deployment with 4 replicas and no rollingUpdate settings is updated to a new image. What does Kubernetes guarantee about Pod counts during the rollout?
maxUnavailable and maxSurge both default to 25%. With 4 replicas that allows one Pod unavailable and one extra Pod, so the count stays between 3 and 5.
A monitoring agent must run exactly once on every node, including nodes added to the cluster next week. Which workload object fits, and why not the alternative?
A DaemonSet places one Pod per eligible node and covers new nodes automatically. A Deployment counts replicas without caring which nodes they land on.