Fixes #39067 - rebuild only if host powered off

[sbernhard]

Rebuild a host is sometimes not possibe if the host is powered on.

e.g. there are 2 issues for bootdisk:

1. on vsphere, if the host is running, the bootdisk can not be attached. To fix this in a user friendly manner, its not possible to fix this only in foreman_bootdisk
2. the current mechanism for vsphere in foreman_bootdisk is, that it restarts the host during attaching the iso image - without a warning that this happens. this isn't user friendly as it is not done for image/network based deployment.

Requires theforeman/foreman_bootdisk#180

This is how it currently look like:

[stejskalleos]

Question: What if Foreman stopped the machine before/during the rebuild action?
What's the point in rebuilding the VM host without rebooting?
Can we break something if we introduce such a behavior?

[stejskalleos]

I'm not sure that this is the right place for the method.

Should the host model be the one who decides if it needs to be powered off, when it's the compute resource who defines this provisioning method, and therefore should keep this information as well.

Looking at can_be_built?

  def can_be_built?
    managed? && !image_build? && !build?
  end

managed & build are attrs, and image_build? is a method in managed.rb:

  def image_build?
    provision_method == 'image'
  end

It feels weird to me, I need to think about it.

[sbernhard]

this method is used to determine, if the "re-build" method (= press the 'Build' button) requires that the host is powered off.
It will try to ask the used provision_method. So,in case of foreman_bootdisk, https://github.com/theforeman/foreman_bootdisk/pull/180/changes#diff-64bce33ed5907be7299b1be146db9be2a5c5a4d8b5e726187911c3c0ff38ec32R34 this will answer with "true"

So, the behavior can be adjusted for each provision_method in general. IF the host needs to be turned of is then related on the actual state of the host with the UI / react.

[sbernhard]

how can we continue with this @stejskalleos ?

[ekohl]

The actual changing of a host to build mode happens in PUT /api/v2/hosts/:id:

foreman/app/controllers/api/v2/hosts_controller.rb

Lines 153 to 166 in 1981e78

	api :PUT, "/hosts/:id/", N_("Update a host")
	param :id, :identifier, :required => true
	param_group :host
	def update
	@parameters = true
	@all_parameters = true
	@host.attributes = host_attributes(host_params, @host)
	process_response @host.save
	rescue InterfaceTypeMapper::UnknownTypeException => e
	render_error :custom_error, :status => :unprocessable_entity, :locals => { :message => e.to_s }
	end

But perhaps it should be done at the model layer that prevents a save in the first place.

[sbernhard]

But perhaps it should be done at the model layer that prevents a save in the first place.
Implemented as validation and added some tests. please have a look again.

[sbernhard]

@stejskalleos ready to merge.

[stejskalleos]

@stejskalleos ready to merge.

Working on my test setup, it's on my board for this week. Code LGTM, so if there are no test issues, I think we can merge.

[stejskalleos]

🍏 LGTM

Tested with Packit packit/theforeman-foreman-10860 rhel-9-x86_64 and with rubygem-foreman_bootdisk-23.1.2-1.20260206220301374331.pr180.5.g2a5e190.el9.noarch, works as expected.

[stejskalleos]

Failed container job is not related to the PR changes, merging.

[stejskalleos]

thanks @sbernhard