1. Create a merge commit PR commit log: 1 2 commit c1 commit c2 Integration branch commit log: 1 2 3 commit PR #NUM commit c2 commit c1 Create a merge commit carries every commit in the PR over to the integration branch intact, and adds one PR commit entry on top.

1. Problem Description When a Webhook was configured to automatically trigger a Jenkins pipeline, the following error occurred: 1 2 3 hudson.plugins.git.GitException: Command "git checkout -f 23b446ea" returned status code 128: stdout: stderr: fatal: reference is not a tree: 23b446ea 2. How Git Manages Versions Git is a content-addressable filesystem. Git maintains a sha tree, and any historical node can be traced back to via its sha value.

1. About Prow In the GitHub repositories of well-known projects such as Kubernetes and Istio, we often see an xxx-bot user adding labels to issues and merging PRs. That bot account is driven by Prow. Prow is a project of the Kubernetes Testing Special Interest Group and is currently part of kubernetes/test-infra.

1. What Left Shift Is It should be noted that “left” here is not the political left, standing for conservatism or radicalism, but the left that describes a process — moving things earlier in time. I first came across “left shift” while researching automated testing. The idea is appealing, and putting it into practice is simple.

1. Test Layering The purpose of testing is to verify expected behavior and uncover latent defects. Testing strengthens confidence that a qualified product can be delivered, and it is what makes agile iteration possible. You could say that testing determines the development pace of a product. The network model has the seven-layer OSI and the four-layer TCP, while development patterns include MTV, MVC, MVP, MVVM, and so on.