Technical guides from production systems
Evidence-based technical content on Nginx, Docker, GitLab, migration, security and production operations.
Production issues and engineering decisions
Recognize symptoms, understand risks and choose the right response.
Why Does Nginx 502 Bad Gateway Occur?
A practical guide to the relationship between 502 errors, backend applications, Docker networking, socket permissions and system resources.
What Should You Check When a Docker Container Keeps Restarting?
Diagnose restart loops through container state, exit codes, logs, resource limits and service dependencies instead of concealing them with repeated restarts.
How Should GitLab Be Migrated to a New Server?
A GitLab migration is not merely a repository copy. PostgreSQL, Redis, LFS, artifacts, Registry, Runners, secrets and external integrations must be planned together.
How to Diagnose a GitLab Runner Job Stuck in Pending
A Pending job often indicates no eligible Runner, exhausted capacity, tag or protection rules, or Runner connectivity problems. Identify the blocking layer before changing registration.
What Should a GitLab Backup and Restore Plan Include?
A generated backup file does not prove recoverability. Scope, encryption keys, external storage, version compatibility and an isolated restore test must be validated together.