An Init Container in Kubernetes is a special type of container that runs before the main application containers in a Pod start running. It is primarily used for performing setup tasks that need to be completed before the main containers start execution.
Why Use Init Containers?
- Dependency Management: Ensures that prerequisites (like fetching config files, setting up databases, etc.) are done before starting the main container.
- Security: Keeps initialization tasks separate from the main application, reducing security risks.
- Failure Handling: If an Init Container fails, Kubernetes restarts it until it succeeds, ensuring correct setup.
- Resource Optimization: Allows heavy initialization work to be offloaded from the main application container.
How Init Containers Work?
- Init Containers always run to completion before the main containers start.
- They run sequentially, meaning one Init Container must finish before the next starts.
- If an Init Container fails, Kubernetes restarts it until it succeeds or the pod reaches its restart limit.
kubectl edit pod
