Do not allow to use `CI_PIPELINE_ID` in environment name

app/models/ci/pipeline.rb

@@ -523,9 +523,14 @@ module Ci
       strong_memoize(:legacy_trigger) { trigger_requests.first }
     end
 
+    def persisted_variables
+      Gitlab::Ci::Variables::Collection.new.tap do |variables|
+        variables.append(key: 'CI_PIPELINE_ID', value: id.to_s) if persisted?
+      end
+    end
+
     def predefined_variables
-      Gitlab::Ci::Variables::Collection.new
-        .append(key: 'CI_PIPELINE_ID', value: id.to_s)
+      persisted_variables
         .append(key: 'CI_CONFIG_PATH', value: ci_yaml_file_path)
         .append(key: 'CI_PIPELINE_SOURCE', value: source.to_s)
         .append(key: 'CI_COMMIT_MESSAGE', value: git_commit_message)

spec/models/ci/pipeline_spec.rb

@@ -167,6 +167,28 @@ describe Ci::Pipeline, :mailer do
     end
   end
 
+  describe '#persisted_variables' do
+    context 'when pipeline is not persisted yet' do
+      subject { build(:ci_pipeline).persisted_variables }
+
+      it 'does not contain some variables' do
+        keys = subject.map { |variable| variable[:key] }
+
+        expect(keys).not_to include 'CI_PIPELINE_ID'
+      end
+    end
+
+    context 'when pipeline is persisted' do
+      subject { build_stubbed(:ci_pipeline).persisted_variables }
+
+      it 'does not contain some variables' do
+        keys = subject.map { |variable| variable[:key] }
+
+        expect(keys).to include 'CI_PIPELINE_ID'
+      end
+    end
+  end
+
   describe '#predefined_variables' do
     subject { pipeline.predefined_variables }