Use new runners registration token to register CI runners

config/initializers/4_ci_app.rb

 module GitlabCi
   VERSION = Gitlab::VERSION
   REVISION = Gitlab::REVISION
-  
-  REGISTRATION_TOKEN = SecureRandom.hex(10)
 
   def self.config
     Settings

lib/ci/api/helpers.rb

@@ -6,7 +6,7 @@ module Ci
       UPDATE_RUNNER_EVERY = 60
 
       def authenticate_runners!
-        forbidden! unless params[:token] == GitlabCi::REGISTRATION_TOKEN
+        forbidden! unless runner_registration_token_valid?
       end
 
       def authenticate_runner!
@@ -22,6 +22,10 @@ module Ci
         forbidden! unless token && build.valid_token?(token)
       end
 
+      def runner_registration_token_valid?
+        params[:token] == current_application_settings.runners_registration_token
+      end
+
       def update_runner_last_contact
         # Use a random threshold to prevent beating DB updates
         contacted_at_max_age = UPDATE_RUNNER_EVERY + Random.rand(UPDATE_RUNNER_EVERY)

lib/ci/api/runners.rb

@@ -40,7 +40,7 @@ module Ci
           required_attributes! [:token]
 
           runner =
-            if params[:token] == GitlabCi::REGISTRATION_TOKEN
+            if runner_registration_token_valid?
               # Create shared runner. Requires admin access
               Ci::Runner.create(
                 description: params[:description],

spec/requests/ci/api/runners_spec.rb

@@ -4,8 +4,11 @@ describe Ci::API::API do
   include ApiHelpers
   include StubGitlabCalls
 
+  let(:registration_token) { 'abcdefg123456' }
+
   before do
     stub_gitlab_calls
+    stub_application_setting(runners_registration_token: registration_token)
   end
 
   describe "GET /runners" do
@@ -33,20 +36,20 @@ describe Ci::API::API do
 
   describe "POST /runners/register" do
     describe "should create a runner if token provided" do
-      before { post ci_api("/runners/register"), token: GitlabCi::REGISTRATION_TOKEN }
+      before { post ci_api("/runners/register"), token: registration_token }
 
       it { expect(response.status).to eq(201) }
     end
 
     describe "should create a runner with description" do
-      before { post ci_api("/runners/register"), token: GitlabCi::REGISTRATION_TOKEN, description: "server.hostname" }
+      before { post ci_api("/runners/register"), token: registration_token, description: "server.hostname" }
 
       it { expect(response.status).to eq(201) }
       it { expect(Ci::Runner.first.description).to eq("server.hostname") }
     end
 
     describe "should create a runner with tags" do
-      before { post ci_api("/runners/register"), token: GitlabCi::REGISTRATION_TOKEN, tag_list: "tag1, tag2" }
+      before { post ci_api("/runners/register"), token: registration_token, tag_list: "tag1, tag2" }
 
       it { expect(response.status).to eq(201) }
       it { expect(Ci::Runner.first.tag_list.sort).to eq(["tag1", "tag2"]) }