Add GraphQL endpoint to list agent configurations (via KAS)

https://gitlab.com/gitlab-org/gitlab/-/merge_requests/62646

Changelog: added
EE: true

doc/api/graphql/reference/index.md

@@ -4247,6 +4247,29 @@ Some of the types in the schema exist solely to model connections. Each connecti
 has a distinct, named type, with a distinct named edge type. These are listed separately
 below.
 
+#### `AgentConfigurationConnection`
+
+The connection type for [`AgentConfiguration`](#agentconfiguration).
+
+##### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="agentconfigurationconnectionedges"></a>`edges` | [`[AgentConfigurationEdge]`](#agentconfigurationedge) | A list of edges. |
+| <a id="agentconfigurationconnectionnodes"></a>`nodes` | [`[AgentConfiguration]`](#agentconfiguration) | A list of nodes. |
+| <a id="agentconfigurationconnectionpageinfo"></a>`pageInfo` | [`PageInfo!`](#pageinfo) | Information to aid in pagination. |
+
+#### `AgentConfigurationEdge`
+
+The edge type for [`AgentConfiguration`](#agentconfiguration).
+
+##### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="agentconfigurationedgecursor"></a>`cursor` | [`String!`](#string) | A cursor for use in pagination. |
+| <a id="agentconfigurationedgenode"></a>`node` | [`AgentConfiguration`](#agentconfiguration) | The item at the end of the edge. |
+
 #### `AlertManagementAlertConnection`
 
 The connection type for [`AlertManagementAlert`](#alertmanagementalert).
@@ -6886,6 +6909,16 @@ Represents the access level of a relationship between a User and object that it
 | <a id="accesslevelintegervalue"></a>`integerValue` | [`Int`](#int) | Integer representation of access level. |
 | <a id="accesslevelstringvalue"></a>`stringValue` | [`AccessLevelEnum`](#accesslevelenum) | String representation of access level. |
 
+### `AgentConfiguration`
+
+Configuration details for an Agent.
+
+#### Fields
+
+| Name | Type | Description |
+| ---- | ---- | ----------- |
+| <a id="agentconfigurationagentname"></a>`agentName` | [`String`](#string) | Name of the agent. |
+
 ### `AlertManagementAlert`
 
 Describes an alert from the project's Alert Management.
@@ -11036,6 +11069,7 @@ Represents vulnerability finding of a security report on the pipeline.
 | Name | Type | Description |
 | ---- | ---- | ----------- |
 | <a id="projectactualrepositorysizelimit"></a>`actualRepositorySizeLimit` | [`Float`](#float) | Size limit for the repository in bytes. |
+| <a id="projectagentconfigurations"></a>`agentConfigurations` | [`AgentConfigurationConnection`](#agentconfigurationconnection) | Agent configurations defined by the project. (see [Connections](#connections)) |
 | <a id="projectallowmergeonskippedpipeline"></a>`allowMergeOnSkippedPipeline` | [`Boolean`](#boolean) | If `only_allow_merge_if_pipeline_succeeds` is true, indicates if merge requests of the project can also be merged with skipped jobs. |
 | <a id="projectapifuzzingciconfiguration"></a>`apiFuzzingCiConfiguration` | [`ApiFuzzingCiConfiguration`](#apifuzzingciconfiguration) | API fuzzing configuration for the project. |
 | <a id="projectarchived"></a>`archived` | [`Boolean`](#boolean) | Indicates the archived status of the project. |

ee/app/graphql/ee/types/project_type.rb

@@ -89,6 +89,12 @@ module EE
               resolver: ::Resolvers::DastSiteValidationResolver,
               description: 'DAST Site Validations associated with the project.'
 
+        field :agent_configurations,
+              ::Types::Kas::AgentConfigurationType.connection_type,
+              null: true,
+              description: 'Agent configurations defined by the project',
+              resolver: ::Resolvers::Kas::AgentConfigurationsResolver
+
         field :cluster_agent,
               ::Types::Clusters::AgentType,
               null: true,

ee/app/graphql/resolvers/kas/agent_configurations_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  module Kas
+    class AgentConfigurationsResolver < BaseResolver
+      type Types::Kas::AgentConfigurationType, null: true
+
+      # Calls Gitaly via KAS
+      calls_gitaly!
+
+      alias_method :project, :object
+
+      def resolve
+        return [] unless can_read_agent_configuration?
+
+        kas_client.list_agent_config_files(project: project)
+      rescue GRPC::BadStatus => e
+        raise Gitlab::Graphql::Errors::ResourceNotAvailable, e.class.name
+      end
+
+      private
+
+      def can_read_agent_configuration?
+        project.licensed_feature_available?(:cluster_agents) && current_user.can?(:admin_cluster, project)
+      end
+
+      def kas_client
+        @kas_client ||= Gitlab::Kas::Client.new
+      end
+    end
+  end
+end

ee/app/graphql/types/kas/agent_configuration_type.rb

+# frozen_string_literal: true
+
+module Types
+  module Kas
+    # rubocop: disable Graphql/AuthorizeTypes
+    class AgentConfigurationType < BaseObject
+      graphql_name 'AgentConfiguration'
+      description 'Configuration details for an Agent'
+
+      field :agent_name,
+            GraphQL::STRING_TYPE,
+            null: true,
+            description: 'Name of the agent.'
+    end
+    # rubocop: enable Graphql/AuthorizeTypes
+  end
+end

ee/spec/graphql/resolvers/kas/agent_configurations_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::Kas::AgentConfigurationsResolver do
+  include GraphqlHelpers
+
+  it { expect(described_class.type).to eq(Types::Kas::AgentConfigurationType) }
+  it { expect(described_class.null).to be_truthy }
+  it { expect(described_class.field_options).to include(calls_gitaly: true) }
+
+  describe '#resolve' do
+    let_it_be(:project) { create(:project) }
+
+    let(:user) { create(:user, maintainer_projects: [project]) }
+    let(:ctx) { Hash(current_user: user) }
+    let(:feature_available) { true }
+
+    let(:agent1) { double }
+    let(:agent2) { double }
+    let(:kas_client) { instance_double(Gitlab::Kas::Client, list_agent_config_files: [agent1, agent2]) }
+
+    subject { resolve(described_class, obj: project, ctx: ctx) }
+
+    before do
+      stub_licensed_features(cluster_agents: feature_available)
+
+      allow(Gitlab::Kas::Client).to receive(:new).and_return(kas_client)
+    end
+
+    it 'returns agents configured for the project' do
+      expect(subject).to contain_exactly(agent1, agent2)
+    end
+
+    context 'an error is returned from the KAS client' do
+      before do
+        allow(kas_client).to receive(:list_agent_config_files).and_raise(GRPC::DeadlineExceeded)
+      end
+
+      it 'raises a graphql error' do
+        expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable, 'GRPC::DeadlineExceeded')
+      end
+    end
+
+    context 'feature is not available' do
+      let(:feature_available) { false }
+
+      it { is_expected.to be_empty }
+    end
+
+    context 'user does not have permission' do
+      let(:user) { create(:user) }
+
+      it { is_expected.to be_empty }
+    end
+  end
+end

ee/spec/graphql/types/kas/agent_configuration_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabSchema.types['AgentConfiguration'] do
+  let(:fields) { %i[agent_name] }
+
+  it { expect(described_class.graphql_name).to eq('AgentConfiguration') }
+  it { expect(described_class.description).to eq('Configuration details for an Agent') }
+  it { expect(described_class).to have_graphql_fields(fields) }
+end

ee/spec/graphql/types/project_type_spec.rb

@@ -101,6 +101,41 @@ RSpec.describe GitlabSchema.types['Project'] do
     end
   end
 
+  describe 'agent_configurations' do
+    let_it_be(:query) do
+      %(
+        query {
+          project(fullPath: "#{project.full_path}") {
+            agentConfigurations {
+              nodes {
+                agentName
+              }
+            }
+          }
+        }
+      )
+    end
+
+    let(:agent_name) { 'example-agent-name' }
+    let(:kas_client) { instance_double(Gitlab::Kas::Client, list_agent_config_files: [double(agent_name: agent_name)]) }
+
+    subject { GitlabSchema.execute(query, context: { current_user: user }).as_json }
+
+    before do
+      stub_licensed_features(cluster_agents: true)
+
+      project.add_maintainer(user)
+      allow(Gitlab::Kas::Client).to receive(:new).and_return(kas_client)
+    end
+
+    it 'returns configured agents' do
+      agents = subject.dig('data', 'project', 'agentConfigurations', 'nodes')
+
+      expect(agents.count).to eq(1)
+      expect(agents.first['agentName']).to eq(agent_name)
+    end
+  end
+
   describe 'cluster_agents' do
     let_it_be(:cluster_agent) { create(:cluster_agent, project: project, name: 'agent-name') }
     let_it_be(:query) do