Prevent WRITE opetaions if it's already archived

lib/gitlab/ci/trace.rb

@@ -6,6 +6,7 @@ module Gitlab
       LEASE_TIMEOUT = 1.hour
 
       ArchiveError = Class.new(StandardError)
+      WriteError = Class.new(StandardError)
 
       attr_reader :job
 
@@ -81,7 +82,9 @@ module Gitlab
 
       def write(mode)
         stream = Gitlab::Ci::Trace::Stream.new do
-          if current_path
+          if trace_artifact
+            raise WriteError, 'Already archived'
+          elsif current_path
             File.open(current_path, mode)
           elsif Feature.enabled?('ci_enable_live_trace')
             Gitlab::Ci::Trace::ChunkedIO.new(job)

spec/support/shared_examples/ci_trace_shared_examples.rb

@@ -138,6 +138,28 @@ shared_examples_for 'common trace features' do
     end
   end
 
+  describe '#write' do
+    subject { trace.send(:write, mode) { } }
+
+    let(:mode) { 'wb' }
+
+    context 'when arhicved trace does not exist yet' do
+      it 'does not raise an error' do
+        expect { subject }.not_to raise_error
+      end
+    end
+
+    context 'when arhicved trace already exists' do
+      before do
+        create(:ci_job_artifact, :trace, job: build)
+      end
+
+      it 'raises an error' do
+        expect { subject }.to raise_error('Already archived')
+      end
+    end
+  end
+
   describe '#set' do
     before do
       trace.set("12")

spec/workers/ci/archive_traces_cron_worker_spec.rb

@@ -31,7 +31,7 @@ describe Ci::ArchiveTracesCronWorker do
     it_behaves_like 'archives trace'
 
     context 'when a trace had already been archived' do
-      let!(:build) { create(:ci_build, :success, :trace_artifact, :trace_live) }
+      let!(:build) { create(:ci_build, :success, :trace_live, :trace_artifact) }
       let!(:build2) { create(:ci_build, :success, :trace_live) }
 
       it 'continues to archive live traces' do