UI lists only 100 agents in the select dropdown

Opening this issue to report a problem encountered registering KAS Agents in a single project for potential investigation. There appears to be a limit of Agents that can be registered to a single project of 99. This was the report received:

we have 100+ clusters, where we are pushing base pkgs (helm charts) from CD pipelines. with kas integration i am in progress of doing that with one pipeline. from global(group based) kas-repo all agents are integrated with group permission. when number reached 99. gitlab project stop showing available (but not yet configured ) gke clusters.

Using a bug template just in case that is needed. The customer has offered to join a Zoom call to discuss and potentially show the problem in action if that has value. Mikhail shared that this is very likely a UI limitation.

cc: @anna_vovchenko @nagyv-gitlab @ash2k

Summary

Steps to reproduce

Example Project

What is the current bug behavior?

What is the expected correct behavior?

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of: sudo gitlab-rake gitlab:check SANITIZE=true)

(For installations from source run and paste the output of: sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)

(we will only investigate if the tests are passing)

Possible fixes

Show a warning in the agent registration modal that the UI can manage only 100 agents. For more agents we recommend using Terraform. Link to https://registry.terraform.io/providers/gitlabhq/gitlab/latest/docs/resources/cluster_agent_token

Follow-up:

• Write a dedicated docs page that describes how to use Terraform with GitLab to manage agents.

Alternatively:

Show the warning with an alternative text at a much lower number where automation already makes a lot of sense, like 10 agents.

To manage more agents, use Terraform.

For 100+ agents:

We only support 100 agents on the UI. To manage more agents, use Terraform.

Implementation guide

1. In the app/assets/javascripts/clusters_list/components/install_agent_modal.vue check the number of agent configurations returned by the agentConfigurations query.
2. Add a GlAlert of type warning that is not dismissible above the agents dropdown (before the <form> element)
3. Use the copy from the Possible fixes section
4. Update spec/frontend/clusters_list/components/install_agent_modal_spec.js with the corresponding specs.