February 22, 2026
Jenkins failures fall into a few categories: builds stuck waiting, cryptic pipeline errors, performance degradation, and Kubernetes agent pods that refuse to launch.
When a build sits in the queue and never starts, check the queue tooltip in the UI – it tells you why. Common causes:
No agents with matching labels. The pipeline requests agent { label 'docker-arm64' } but no agent has that label. Check Manage Jenkins > Nodes to see available labels.
February 22, 2026
Jenkins is a self-hosted automation server. Unlike managed CI services, you own the infrastructure, which means you control everything from plugin versions to executor capacity. This guide covers the three main installation methods and the configuration patterns that make Jenkins manageable at scale.
The fastest way to run Jenkins locally or in a VM:
docker run -d \
--name jenkins \
-p 8080:8080 \
-p 50000:50000 \
-v jenkins_home:/var/jenkins_home \
jenkins/jenkins:lts-jdk17Port 8080 is the web UI. Port 50000 is the JNLP agent port for inbound agent connections. The volume mount is critical – without it, all configuration and build history is lost when the container restarts.