CI

Overview 2:47 AM, the alert chat exploded. A payment service’s P99 latency spiked from 80ms to 1200ms after a new version went live. The on-call engineer hit rollback immediately. kubectl rollout undo executed successfully, old version Pods came back up, traffic shifted back. The result? The service went completely down — because the new version had run a database migration script that changed the status column in the orders table from varchar(20) to tinyint....

Overview 2 AM, alert fires. Investigation reveals a server running an outdated OpenSSL version with known vulnerabilities. Security team asks: how many more machines are in the same state? You don’t have an answer. That’s the cost of configuring servers manually. Each machine gets its own apt install, producing environments that drift apart. Someone forgot a patch, someone installed extra packages, someone changed a kernel parameter without documenting it. When things break, you realize—you have no idea how many “configuration drift” variants are running in production....

Overview You’ve probably seen this release workflow: a developer builds a Docker image, tags it as dev, and pushes it to the dev registry. After testing passes, they re-tag it as staging and push it again. Finally, for production, they tag it as prod and push a third time. Same image, built once, pushed three times with three different tags. This seems fine — until one day you discover that the image validated in staging and the image running in prod are not the same artifact at all....

Overview Plug a SAST tool into your Jenkins pipeline, let the scan finish with zero alerts, then tell your boss “we’ve adopted DevSecOps” — I’ve seen this playbook too many times. During a Level 2 cybersecurity protection audit for a ride-hailing project, the client’s security team required us to integrate security scanning into our CI/CD pipeline. The first version was textbook standard: SonarQube for code scanning + Trivy for image scanning, with the gate set to “block Critical....

Overview 1 AM. You get an alert: GitLab CI pipeline queue has 47 pending jobs. The dev chat explodes—“code pushed 40 minutes ago, still not running"“is the Runner down?““just add more machines!” You check the console: all 3 Runners are at capacity, each running 10 concurrent jobs, 30 slots fully occupied. Add machines? Docker Machine executor needs 3 minutes to spin up a new EC2, then another 2 minutes to become Ready....

Overview 2 AM. A ride-hailing platform’s release window just opened. Jenkins Master suddenly hits CPU 100%. The build queue backs up with 200+ tasks. The entire deployment pipeline is frozen. The ops team spent 40 minutes finding the root cause: a legacy project’s Git repo had 15GB of binary files stuffed in it. A single clone took 20 minutes, exhausting all of Master’s thread pool. This isn’t an isolated case. Jenkins is a fine CI tool, but when you have 120+ microservices with tangled deployment dependencies and need fine-grained control over concurrency and rollback ordering, Jenkins’s Stage model starts to crack....

Overview You have probably experienced this scenario: a developer commits one line of code, CI runs for 40 minutes, CD deployment takes another 20. You come back after two cups of coffee only to find the build failed—time to start over. By the end of the day, three hours gone just waiting on the pipeline. This is not an isolated case. Among the teams I have worked with, the majority have pipelines exceeding 30 minutes....

Overview Jenkins users fall into two camps: one fills out forms on the web UI, clicks a few buttons, and gets things running — simple and direct. The other writes Jenkinsfiles in the code repository, turning build pipelines into code with version control, peer review, and rollback all built in. The first is called Freestyle Project. The second is called Pipeline Project. These two aren’t mutually exclusive. Many teams use both — simple script tasks with Freestyle, complex multi-stage releases with Pipeline....

Overview Vulnerability Scanning in CI/CD: From Dependency Checks to Image Security is an essential skill in SRE operations. In production environments, mastering these techniques can significantly improve system stability and operational efficiency. Why Vulnerability Scanning in CI/CD Matters As systems grow in scale and complexity, traditional operations approaches struggle to meet the demands of modern distributed systems. Vulnerability Scanning in CI/CD helps operations teams: Rapid Problem Resolution: Systematic tools and methods reduce troubleshooting time Improved System Visibility: Establish comprehensive monitoring and observability Proactive Fault Prevention: Identify and fix potential risks before they cause outages Resource Optimization: Allocate and schedule resources efficiently Core Concepts and Principles Basic Concepts The core of Vulnerability Scanning in CI/CD lies in establishing standardized processes and automated toolchains....

Overview Code Review Automation: Lint, CI, and Intelligent Checking Toolchains is an essential skill in SRE operations. In production environments, mastering these techniques can significantly improve system stability and operational efficiency. Why Code Review Automation Matters As systems grow in scale and complexity, traditional operations approaches struggle to meet the demands of modern distributed systems. Code Review Automation helps operations teams: Rapid Problem Resolution: Systematic tools and methods reduce troubleshooting time Improved System Visibility: Establish comprehensive monitoring and observability Proactive Fault Prevention: Identify and fix potential risks before they cause outages Resource Optimization: Allocate and schedule resources efficiently Core Concepts and Principles Basic Concepts The core of Code Review Automation lies in establishing standardized processes and automated toolchains....