ironic/doc/source/contributor/deploy-steps.rst

Developing a new Deploy Step

To support customized deployment step, implement a new method in an interface class and use the decorator deploy_step defined in ironic/drivers/base.py. For example, we will implement a do_nothing deploy step in the AgentDeploy class.

from ironic.drivers.modules import agent

class AgentDeploy(agent.AgentDeploy):

    @base.deploy_step(priority=200, argsinfo={
        'test_arg': {
            'description': (
                "This is a test argument."
            ),
            'required': True
        }
    })
    def do_nothing(self, task, **kwargs):
        return None

If you want to completely replace the deployment procedure, but still have the agent up and running, inherit CustomAgentDeploy:

from ironic.drivers.modules import agent

class AgentDeploy(agent.CustomAgentDeploy):

    def validate(self, task):
        super().validate(task)
        # ... custom validation

    @base.deploy_step(priority=80)
    def my_write_image(self, task, **kwargs):
        pass  # ... custom image writing

    @base.deploy_step(priority=70)
    def my_configure_bootloader(self, task, **kwargs):
        pass  # ... custom bootloader configuration

After deployment of the baremetal node, check the updated deploy steps:

baremetal node show $node_ident -f json -c driver_internal_info

The above command outputs the driver_internal_info as following:

{
  "driver_internal_info": {
    ...
    "deploy_steps": [
      {
        "priority": 200,
        "interface": "deploy",
        "step": "do_nothing",
        "argsinfo":
          {
            "test_arg":
              {
                "required": True,
                "description": "This is a test argument."
              }
          }
      },
      {
        "priority": 100,
        "interface": "deploy",
        "step": "deploy",
        "argsinfo": null
      }
    ],
    "deploy_step_index": 1
  }
}

Note

Similarly, clean steps can be implemented using the clean_step decorator.

In-band deploy steps (deploy steps that are run inside the ramdisk) have to be implemented in a custom IPA hardware manager <contributor/hardware_managers.html#custom-hardwaremanagers-and-deploying>. All in-band deploy steps must have priorities between 41 and 99, see node-deployment-core-steps for details.