Enable creation of deploy keys with write access via the API

* Documentation was incorrectly advertising the missing param

changelogs/unreleased/30021-api-deploy_keys-can_push-is-not-honoured.yml

+---
+title: Enable creation of deploy keys with write access via the API
+merge_request:
+author:

lib/api/deploy_keys.rb

@@ -47,6 +47,7 @@ module API
       params do
         requires :key, type: String, desc: 'The new deploy key'
         requires :title, type: String, desc: 'The name of the deploy key'
+        optional :can_push, type: Boolean, desc: "Can deploy key push to the project's repository"
       end
       post ":id/deploy_keys" do
         params[:key].strip!

spec/factories/keys.rb

@@ -23,5 +23,9 @@ FactoryGirl.define do
       factory :another_deploy_key, class: 'DeployKey' do
       end
     end
+
+    factory :write_access_key, class: 'DeployKey' do
+      can_push true
+    end
   end
 end

spec/requests/api/deploy_keys_spec.rb

@@ -108,6 +108,15 @@ describe API::DeployKeys, api: true  do
 
       expect(response).to have_http_status(201)
     end
+
+    it 'accepts can_push parameter' do
+      key_attrs = attributes_for :write_access_key
+
+      post api("/projects/#{project.id}/deploy_keys", admin), key_attrs
+
+      expect(response).to have_http_status(201)
+      expect(json_response['can_push']).to eq(true)
+    end
   end
 
   describe 'DELETE /projects/:id/deploy_keys/:key_id' do