pre-provision-command
The --pre-provision-command for the caph controller can be used to execute a custom command before install-image starts.
This provides you a flexible way to check if the bare metal server is healthy.
Example:
--pre-provision-command=/shared/my-pre-provision-command.sh
The script/binary will be copied into the Hetzner Rescue System and executed.
If the exit code is zero, then all is fine.
If the exit code is non-zero, then provisioning of that machine will be stopped.
The CAPH controller runs in a Kubernetes Pod. The container of that pod needs access to the file.
There are several ways to make this command available:
- You could mount a configMap/secret.
- You create a container image, and use that as init-container.
- You build a custom image of CAPH. We do not recommend that.
In this example we use an init-container to provide the script.
In the directory images/pre-provision-command/ you see these files:
- my-pre-provision-command.sh: A simple Bash script which creates a message and exists with 0.
- Dockerfile: Needed to create a container image.
- build-and-push.sh: A script to build and upload the script to a container registry.
When the container image was uploaded, you need to adapt the CAPH deployment:
# Init container, which makes the command available to caph.
initContainers:
- command:
- /bin/sh
- -c
- cp /my-pre-provision-command.sh /shared/
image: ghcr.io/syself/caph-staging:pre-provision-command
imagePullPolicy: Always
name: init-container
resources: {}
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
volumeMounts:
- mountPath: /shared
name: shared
# Add this to the args of the caph container:
args:
- --pre-provision-command=/shared/my-pre-provision-command.sh
# Add this to the caph container
volumeMounts:
- mountPath: /shared
name: shared
# Add this after "container"
volumes:
- emptyDir: {}
name: shared