Merge branch 'master' into ci/api-triggers

* master:
  Fix version
  Improve the consistency of commit titles, branch names, tag names, issue/MR titles, on their respective project pages
  Update CHANGELOG [ci skip]
  Add some cosmetic changes to variables API documentation [ci skip]
  Modify builds API documentation style [ci skip]
  Modify :ci_variable factory
  Add 'Build' prefix to Variables entry name in API docs index
  Fix some typos
  Add some fixes after review
  Remove blank line
  Update ./doc/api
  Change :variable_id to :key as resource ID in API
  Fix a typo in method description
  Add create feature to variables API
  Add missing 'not_found' checks in variables API
  Add delete feature to variables API
  Add update feature for variables API
  Add features for list and show details of variables in API

Conflicts:
	doc/api/README.md
	lib/api/entities.rb

3 files changed, 100 insertions, 0 deletions

diff --git a/lib/api/api.rb b/lib/api/api.rb
index 7834262d612..098dd975840 100644
--- a/lib/api/api.rb
+++ b/lib/api/api.rb
@@ -54,5 +54,6 @@ module API
     mount Keys
     mount Tags
     mount Triggers
+    mount Variables
   end
 end
diff --git a/lib/api/entities.rb b/lib/api/entities.rb
index 00c933237fe..d3803f4ec70 100644
--- a/lib/api/entities.rb
+++ b/lib/api/entities.rb
@@ -370,5 +370,9 @@ module API
     class Trigger < Grape::Entity
       expose :token, :created_at, :updated_at, :deleted_at, :last_used
     end
+
+    class Variable < Grape::Entity
+      expose :key, :value
+    end
   end
 end
diff --git a/lib/api/variables.rb b/lib/api/variables.rb
new file mode 100644
index 00000000000..d9a055f6c92
--- /dev/null
+++ b/lib/api/variables.rb
@@ -0,0 +1,95 @@
+module API
+  # Projects variables API
+  class Variables < Grape::API
+    before { authenticate! }
+    before { authorize_admin_project }
+
+    resource :projects do
+      # Get project variables
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   page (optional) - The page number for pagination
+      #   per_page (optional) - The value of items per page to show
+      # Example Request:
+      #   GET /projects/:id/variables
+      get ':id/variables' do
+        variables = user_project.variables
+        present paginate(variables), with: Entities::Variable
+      end
+
+      # Get specific variable of a project
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   key (required) - The `key` of variable
+      # Example Request:
+      #   GET /projects/:id/variables/:key
+      get ':id/variables/:key' do
+        key = params[:key]
+        variable = user_project.variables.find_by(key: key.to_s)
+
+        return not_found!('Variable') unless variable
+
+        present variable, with: Entities::Variable
+      end
+
+      # Create a new variable in project
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   key (required) - The key of variable
+      #   value (required) - The value of variable
+      # Example Request:
+      #   POST /projects/:id/variables
+      post ':id/variables' do
+        required_attributes! [:key, :value]
+
+        variable = user_project.variables.create(key: params[:key], value: params[:value])
+
+        if variable.valid?
+          present variable, with: Entities::Variable
+        else
+          render_validation_error!(variable)
+        end
+      end
+
+      # Update existing variable of a project
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   key (optional) - The `key` of variable
+      #   value (optional) - New value for `value` field of variable
+      # Example Request:
+      #   PUT /projects/:id/variables/:key
+      put ':id/variables/:key' do
+        variable = user_project.variables.find_by(key: params[:key].to_s)
+
+        return not_found!('Variable') unless variable
+
+        attrs = attributes_for_keys [:value]
+        if variable.update(attrs)
+          present variable, with: Entities::Variable
+        else
+          render_validation_error!(variable)
+        end
+      end
+
+      # Delete existing variable of a project
+      #
+      # Parameters:
+      #   id (required) - The ID of a project
+      #   key (required) - The ID of a variable
+      # Example Request:
+      #   DELETE /projects/:id/variables/:key
+      delete ':id/variables/:key' do
+        variable = user_project.variables.find_by(key: params[:key].to_s)
+
+        return not_found!('Variable') unless variable
+        variable.destroy
+
+        present variable, with: Entities::Variable
+      end
+    end
+  end
+end