Init containers in Kubernetes: examples and use cases

Hey friends! Today, I want to talk about init containers in Kubernetes. These special containers run before standard containers and help preconfigure the environment or set up dependencies. Init containers establish a contract between developers and deployers, ensuring smooth collaboration. They're commonly used to check for dependent services or databases before starting a container. One great use case is fetching secrets or certificates required for the application to start. By using init containers, we can centralise this logic, making it easier to manage and update.
I want to share a specific use case where I found init containers to be extremely useful. It's when you need to fetch secrets or certificates that are essential for your application to start. In the past, before all the vault integration, I used init containers to fetch secrets from Vault and share them on a shared volume.
By doing this, we can centralize the logic within the init container, making it easier to manage and reuse across different deployments. If there's ever a need to change or update the logic around secrets, we can simply swap the container and apply it to all our deployments. It saves us from coordinating with multiple teams and ensures a smooth workflow.
I also want to highlight a useful trick when working with secrets: using a shared volume of type "emptyDir" with the medium set to memory. This creates a volume stored completely in memory, providing an additional layer of security by avoiding disk storage. Moreover, accessing data from memory is much faster than accessing it from a disk attached to the machine.
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[@ahmedsaif4541]

Thank you very much in this great explanation , i just joined your channel and i was looking for how to prevent users to pull the latest image and restrict the pulling from specific registry

[@mar23707]

Thanks for your explanation.

[@pradumnasaraf]

Init containers are super helpful. Great video, Anto.

[@thanhnguyenchi2356]

didn't know Tony Stark was into cloud tech