nodejoiner-command

Development

Describes the acceptance criteria, BDD tests and specific implementation details when developing a new feature (or fixing an issue) related to the node-joiner command.

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Source SKILL.md: https://github.com/openshift/installer/blob/HEAD/pkg/nodejoiner/.claude/skills/nodejoiner-command/SKILL.md

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Implementation details

The nodejoiner is a internal command (not meant to be used directly by the user) wrapped by the oc adm nodeimage command, to allow the user adding a new node to an existing target cluster by building an ISO. The command reuses most of the code of the Agent-based Installer, but since it follows a slightly different workflow some differences have been implemented in the code (through the usage of the workflow.AgentWorkflowTypeAddNodes enum value).

The most important asset is the joiner.ClusterInfo, as it contains the logic to inspect the current target cluster and to extract the input configuration required by the ABI assets to generate the add node ISO. So usually the target cluster is considered the authoritative source of truth for the configuration.

Testing

To run just the unit tests, you must use hack/go-test.sh
To run the specific node-joiner integration test, you must use only hack/go-integration-test-nodejoiner.sh
Integration test prerequisites:
- oc must be installed and in $PATH. Install with: curl -L https://mirror.openshift.com/pub/openshift-v4/clients/ocp/stable/openshift-client-linux.tar.gz -o /tmp/oc.tar.gz && mkdir -p ~/.local/bin && tar -xzf /tmp/oc.tar.gz -C ~/.local/bin oc kubectl && rm /tmp/oc.tar.gz
- Override GOPATH to a writable location (the default /tmp/claude/go is not writable in containers): PATH=$HOME/.local/bin:$PATH GOPATH=$HOME/go hack/go-integration-test-nodejoiner.sh

Useful references

https://github.com/openshift/enhancements/blob/master/enhancements/oc/day2-add-nodes.md. This the official oc enhancement proposal to add a new oc adm nodeimage command for letting the user easily add a new node by building an ISO. The oc command is a thin wrapper of the node-joiner command.
https://github.com/openshift/oc/tree/main/pkg/cli/admin/nodeimage. The code repository for the oc adm nodeimage commands.

Supporting files

acceptance/coreos-bootimages-data.md: how to fetch the coreos bootimages data required for building the ISO.