Detect already enabled DeployKeys in EnableDeployKeyService

Ensures deploy keys can't be re-added, which causes a validation error

3 files changed, 18 insertions, 1 deletions

diff --git a/app/services/projects/enable_deploy_key_service.rb b/app/services/projects/enable_deploy_key_service.rb
index 3cf4264ce9b..121385afca3 100644
--- a/app/services/projects/enable_deploy_key_service.rb
+++ b/app/services/projects/enable_deploy_key_service.rb
@@ -4,7 +4,10 @@ module Projects
       key = accessible_keys.find_by(id: params[:key_id] || params[:id])
       return unless key
 
-      project.deploy_keys << key
+      unless project.deploy_keys.include?(key)
+        project.deploy_keys << key
+      end
+
       key
     end
 
diff --git a/changelogs/unreleased/29673-500-internal-server-error-when-enabling-a-deploy-key-more-than-once-through-api.yml b/changelogs/unreleased/29673-500-internal-server-error-when-enabling-a-deploy-key-more-than-once-through-api.yml
new file mode 100644
index 00000000000..3e62ede1521
--- /dev/null
+++ b/changelogs/unreleased/29673-500-internal-server-error-when-enabling-a-deploy-key-more-than-once-through-api.yml
@@ -0,0 +1,4 @@
+---
+title: Detect already enabled DeployKeys in EnableDeployKeyService
+merge_request:
+author:
diff --git a/spec/services/projects/enable_deploy_key_service_spec.rb b/spec/services/projects/enable_deploy_key_service_spec.rb
index a37510cf159..78626fbad4b 100644
--- a/spec/services/projects/enable_deploy_key_service_spec.rb
+++ b/spec/services/projects/enable_deploy_key_service_spec.rb
@@ -21,6 +21,16 @@ describe Projects::EnableDeployKeyService, services: true do
     end
   end
 
+  context 'add the same key twice' do
+    before do
+      project.deploy_keys << deploy_key
+    end
+
+    it 'returns existing key' do
+      expect(service.execute).to eq(deploy_key)
+    end
+  end
+
   def service
     Projects::EnableDeployKeyService.new(project, user, params)
   end