Cannot re-register existing host

gtrenin · August 16, 2026, 8:05pm

We are running Foreman 3.19.1 / Katello 4.21.0 with RHEL hosts. We do not use Foreman provisioning facilities, but register existing hosts with Foreman.

We are encountering an issue when attempting to re-register an already registered host using the standard curl | bash command generated via the Foreman Web UI (Hosts → Register Host).

The initial registration of a previously unknown host works perfectly. However, running the registration command a second time on the same host fails at the very final step when reporting the build status to the /unattended/built endpoint with a 404 error.

Registration Command Used

curl 'https://smartproxy.query.local.consul.example.com:9090/register?activation_keys=rhel9-dev&download_utility=curl&force=true&location_id=3&organization_id=1&update_packages=false' \
--header 'Authorization: Bearer <TOKEN>' | bash

The following error can be seen in /var/log/foreman/production.log:

2026-08-16T21:46:18 [I|app|0d492957] Started GET "/unattended/built?token=[redacted]&url=http%3A%2F%2Fsmartproxy1.example.com%3A8000" for 192.168.0.3 at 2026-08-16 21:46:18 +0300
2026-08-16T21:46:18 [I|app|0d492957] Processing by UnattendedController#built as TEXT
2026-08-16T21:46:18 [I|app|0d492957]   Parameters: {"token"=>"[redacted]", "url"=>"http://smartproxy1.example.com:8000", "unattended"=>{}}
2026-08-16T21:46:18 [E|app|0d492957] unattended: unable to find a host that matches the request from 192.168.0.3. Search paths: token: [redacted]
2026-08-16T21:46:18 [I|app|0d492957]   Rendered text template (Duration: 0.0ms | Allocations: 2)
2026-08-16T21:46:18 [I|app|0d492957] Completed 404 Not Found in 11ms (Views: 2.9ms | ActiveRecord: 3.1ms | Allocations: 2792)

Tracing back a second earlier revealed that it cannot enter a build state.

2026-08-16T21:46:17 [I|app|62b051d1] Started POST "/register?url=https%3A%2F%2Fsmartproxy.query.local.consul.example.com%3A9090" for
 192.168.0.3 at 2026-08-16 21:46:17 +0300
2026-08-16T21:46:17 [I|app|62b051d1] Processing by Api::V2::RegistrationController#host as HTML
2026-08-16T21:46:17 [I|app|62b051d1]   Parameters: {"uuid"=>"f16f901d-878c-4973-a0e2-39fe9b4f8bfa", "host"=>{"build"=>"false", "organization_id
"=>"1", "location_id"=>"3"}, "update_packages"=>"false", "url"=>"https://smartproxy.query.local.consul.example.com:9090"}
2026-08-16T21:46:17 [I|app|62b051d1] Authorized user admin(Admin User)
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (371) destroy event on name host_update_packages
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (371) destroy event on value false
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (371) destroy event on reference_id 343
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (371) destroy event on hidden_value false
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (371) destroy event on key_type boolean
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (372) create event on name host_update_packages
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (372) create event on value false
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (372) create event on reference_id 343
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (372) create event on hidden_value false
2026-08-16T21:46:17 [I|aud|62b051d1] Parameter (372) create event on key_type boolean
2026-08-16T21:46:17 [W|app|62b051d1] Not queueing Host::Managed: ["Host parameters is invalid"]
2026-08-16T21:46:17 [W|app|62b051d1] Not queueing Host::Managed: ["Host parameters is invalid"]
2026-08-16T21:46:17 [W|app|62b051d1] Not queueing Host::Managed: ["Host parameters is invalid"]
2026-08-16T21:46:17 [W|app|62b051d1] Set build failed: #<ActiveModel::Errors [#<ActiveModel::Error attribute=host_parameters, type=invalid, opt
ions={:value=>#<ActiveRecord::Associations::CollectionProxy [#<HostParameter id: 371, name: "host_update_packages", value: [FILTERED], referenc
e_id: 343, created_at: "2026-08-16 18:45:49.792499000 +0000", updated_at: "2026-08-16 18:45:49.792499000 +0000", type: "HostParameter", priorit
y: 70, hidden_value: [FILTERED], key_type: "boolean", searchable_value: [FILTERED]>]>}>]>

It attempts to destroy and recreate the host_update_packages boolean parameter, and then complains that this parameter is invalid.

Workarounds Found

We can successfully re-register the host if we do either of the following:

Manually delete the host_update_packages parameter from the host in the Foreman UI before running the command.
Manually strip out the &update_packages=false argument from the generated curl URL.

Because the Foreman UI automatically appends the &update_packages argument to the generated registration string by default, this effectively breaks re-registration out-of-the-box for existing hosts.

Is this a known bug, or is there a configuration adjustment we are missing?

vijaysawant · August 17, 2026, 4:22pm

Thanks for providing the detailed logs and the workarounds.

From the logs, it looks like the failure is happening while Foreman tries to update the existing host_update_packages host parameter during re-registration. The parameter is first deleted and then recreated with false, but Foreman considers the host parameters invalid and fails to set the build state. The later /unattended/built 404 appears to be a consequence of this failure.

Since removing host_update_packages or removing update_packages=false from the registration command allows re-registration to succeed, this looks like a potential Foreman bug rather than a configuration issue.

Could you check if the same behavior occurs with another already-registered host? If so, I think this would be useful to reproduce and report upstream, including the production.log entries and the exact registration command.

For now, removing update_packages=false from the registration command appears to be a reasonable workaround if package updating is not required.

vijaysawant · August 17, 2026, 4:29pm

From a QE point of view, my understanding is that re-registration of an existing/known host fails when update_packages=false is used during registration. Is that correct?

gtrenin · August 17, 2026, 4:38pm

I can confirm that the problem reproduces at will with other hosts.

Could you please clarify what the number in brackets means in Parameter (372) ?

I am not very familiar with Ruby, but it looks like the process deleted host_update_packages with ID 371 and re-created it with ID 372. However, the error message still references the deleted ID 371 (as seen in #<HostParameter id: 371).

Does this interpretation make sense?

gtrenin · August 17, 2026, 4:42pm

Exactly. Removing update_packages=false from the curl command allows the host to re-register successfully. However, Foreman includes this parameter by default.

vijaysawant · August 17, 2026, 5:08pm

Yes, your interpretation of the numbers is correct. 371 and 372 are the database IDs of the HostParameter records. The log shows that Foreman destroys the existing host_update_packages parameter (ID 371) and then creates a new one (ID 372).

gtrenin · August 17, 2026, 11:33pm

I think I have pinpointed the bug and opened a Redmine issue and a PR to fix it:

Please don’t judge too harshly, as this is my very first time working with Ruby!

Any feedback on the PR is highly appreciated.

vijaysawant · August 18, 2026, 7:04am

Hey @gtrenin Could you please share redmine issue link as well ?

LadislavVasina1 · August 18, 2026, 7:24am

@vijaysawant

I suppose its this one.