Inroduce Internal API for searching environment names

Add changelog

Rename word to query

User hash for limit

Do not allow control limit

Rename pluck names and add more specs

app/controllers/projects/environments_controller.rb

@@ -158,6 +158,16 @@ class Projects::EnvironmentsController < Projects::ApplicationController
     end
   end
+  def search
+    respond_to do |format|
+      format.json do
+        environment_names = search_environment_names
+
+        render json: environment_names, status: environment_names.any? ? :ok : :no_content
+      end
+    end
+  end
+
   private
   def verify_api_request!
@@ -181,6 +191,12 @@ class Projects::EnvironmentsController < Projects::ApplicationController
     @environment ||= project.environments.find(params[:id])
   end
+  def search_environment_names
+    return [] unless params[:query]
+
+    project.environments.for_name_like(params[:query]).pluck_names
+  end
+
   def serialize_environments(request, response, nested = false)
     EnvironmentSerializer
       .new(project: @project, current_user: @current_user)

app/models/environment.rb

@@ -50,6 +50,14 @@ class Environment < ActiveRecord::Base
   end
   scope :in_review_folder, -> { where(environment_type: "review") }
   scope :for_name, -> (name) { where(name: name) }
+
+  ##
+  # Search environments which have names like the given query.
+  # Do not set a large limit unless you've confirmed that it works on gitlab.com scale.
+  scope :for_name_like, -> (query, limit: 5) do
+    where('name LIKE ?', "#{sanitize_sql_like(query)}%").limit(limit)
+  end
+
   scope :for_project, -> (project) { where(project_id: project) }
   scope :with_deployment, -> (sha) { where('EXISTS (?)', Deployment.select(1).where('deployments.environment_id = environments.id').where(sha: sha)) }
@@ -70,6 +78,10 @@ class Environment < ActiveRecord::Base
     end
   end
+  def self.pluck_names
+    pluck(:name)
+  end
+
   def predefined_variables
     Gitlab::Ci::Variables::Collection.new
       .append(key: 'CI_ENVIRONMENT_NAME', value: name)

changelogs/unreleased/introduce-environment-search-endpoint.yml

+---
+title: Introduce Internal API for searching environment names
+merge_request: 24923
+author:
+type: added

config/routes/project.rb

@@ -224,6 +224,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
         collection do
           get :metrics, action: :metrics_redirect
           get :folder, path: 'folders/*id', constraints: { format: /(html|json)/ }
+          get :search
         end
         resources :deployments, only: [:index] do

spec/controllers/projects/environments_controller_spec.rb

@@ -422,6 +422,79 @@ describe Projects::EnvironmentsController do
     end
   end
+  describe 'GET #search' do
+    before do
+      create(:environment, name: 'staging', project: project)
+      create(:environment, name: 'review/patch-1', project: project)
+      create(:environment, name: 'review/patch-2', project: project)
+    end
+
+    let(:query) { 'pro' }
+
+    it 'responds with status code 200' do
+      get :search, params: environment_params(format: :json, query: query)
+
+      expect(response).to have_gitlab_http_status(:ok)
+    end
+
+    it 'returns matched results' do
+      get :search, params: environment_params(format: :json, query: query)
+
+      expect(json_response).to contain_exactly('production')
+    end
+
+    context 'when query is review' do
+      let(:query) { 'review' }
+
+      it 'returns matched results' do
+        get :search, params: environment_params(format: :json, query: query)
+
+        expect(json_response).to contain_exactly('review/patch-1', 'review/patch-2')
+      end
+    end
+
+    context 'when query is empty' do
+      let(:query) { '' }
+
+      it 'returns matched results' do
+        get :search, params: environment_params(format: :json, query: query)
+
+        expect(json_response)
+          .to contain_exactly('production', 'staging', 'review/patch-1', 'review/patch-2')
+      end
+    end
+
+    context 'when query is review/patch-3' do
+      let(:query) { 'review/patch-3' }
+
+      it 'responds with status code 204' do
+        get :search, params: environment_params(format: :json, query: query)
+
+        expect(response).to have_gitlab_http_status(:no_content)
+      end
+    end
+
+    context 'when query is partially matched in the middle of environment name' do
+      let(:query) { 'patch' }
+
+      it 'responds with status code 204' do
+        get :search, params: environment_params(format: :json, query: query)
+
+        expect(response).to have_gitlab_http_status(:no_content)
+      end
+    end
+
+    context 'when query contains a wildcard character' do
+      let(:query) { 'review%' }
+
+      it 'prevents wildcard injection' do
+        get :search, params: environment_params(format: :json, query: query)
+
+        expect(response).to have_gitlab_http_status(:no_content)
+      end
+    end
+  end
+
   def environment_params(opts = {})
     opts.reverse_merge(namespace_id: project.namespace,
                        project_id: project,

spec/models/environment_spec.rb

@@ -41,6 +41,76 @@ describe Environment do
     end
   end
+  describe '.for_name_like' do
+    subject { project.environments.for_name_like(query, limit: limit) }
+
+    let!(:environment) { create(:environment, name: 'production', project: project) }
+    let(:query) { 'pro' }
+    let(:limit) { 5 }
+
+    it 'returns a found name' do
+      is_expected.to include(environment)
+    end
+
+    context 'when query is production' do
+      let(:query) { 'production' }
+
+      it 'returns a found name' do
+        is_expected.to include(environment)
+      end
+    end
+
+    context 'when query is productionA' do
+      let(:query) { 'productionA' }
+
+      it 'returns empty array' do
+        is_expected.to be_empty
+      end
+    end
+
+    context 'when query is empty' do
+      let(:query) { '' }
+
+      it 'returns a found name' do
+        is_expected.to include(environment)
+      end
+    end
+
+    context 'when query is nil' do
+      let(:query) { }
+
+      it 'raises an error' do
+        expect { subject }.to raise_error(NoMethodError)
+      end
+    end
+
+    context 'when query is partially matched in the middle of environment name' do
+      let(:query) { 'duction' }
+
+      it 'returns empty array' do
+        is_expected.to be_empty
+      end
+    end
+
+    context 'when query contains a wildcard character' do
+      let(:query) { 'produc%' }
+
+      it 'prevents wildcard injection' do
+        is_expected.to be_empty
+      end
+    end
+  end
+
+  describe '.pluck_names' do
+    subject { described_class.pluck_names }
+
+    let!(:environment) { create(:environment, name: 'production', project: project) }
+
+    it 'plucks names' do
+      is_expected.to eq(%w[production])
+    end
+  end
+
   describe '#expire_etag_cache' do
     let(:store) { Gitlab::EtagCaching::Store.new }