Init Containers and Startup Ordering
Learn how init containers run setup tasks before your main app containers start, and how they enforce ordering inside a Pod.
What Are Init Containers?
An init container is a special container that runs to completion before the main app containers in a Pod start. Pods can have one or more of them.
They are perfect for one-time setup tasks: waiting for a dependency, cloning config, or running a database migration.
How They Differ from App Containers
Init containers always run to completion and must succeed before the next one starts. App containers, by contrast, run continuously.
- Init containers run sequentially, one at a time
- App containers run in parallel
- If an init container fails, the Pod restarts it (per restartPolicy)
All lessons in this course
- Pods: The Smallest Unit
- Pod Lifecycle and States
- Multi-Container Pods (Sidecars)
- Init Containers and Startup Ordering