Make it possible to persist a final build trace chunk

Build trace chunk is considered to be final (is the last part of a build
log and we do not expect it to ever become full) when a runner submitted
a build pending state and there is no chunk with higher index in the
database.

app/models/ci/build_trace_chunk.rb

@@ -118,6 +118,16 @@ module Ci
       redis?
     end
 
+    ##
+    # Build trace chunk is final (the last one that we do not expect to ever
+    # become full) when a runner submitted a build pending state and there is
+    # no chunk with higher index in the database.
+    #
+    def final?
+      build.pending_state.present? &&
+        build.trace_chunks.maximum(:chunk_index).to_i == chunk_index
+    end
+
     private
 
     def get_data
@@ -130,9 +140,9 @@ module Ci
 
       current_data = data
       old_store_class = current_store
+      current_size = current_data&.bytesize.to_i
 
-      ## TODO allow final chunk update if build pending state exists
-      unless current_data&.bytesize.to_i == CHUNK_SIZE
+      unless current_size == CHUNK_SIZE || final?
         raise FailedToPersistDataError, 'Data is not fulfilled in a bucket'
       end
 

lib/api/ci/runner.rb

@@ -177,8 +177,11 @@ module API
 
           Gitlab::Metrics.add_event(:update_build)
 
-          ::Ci::UpdateBuildStateService.new(job, params).then do |service|
-            service.execute.then { |result| status result.status }
+          service = ::Ci::UpdateBuildStateService
+            .new(job, declared_params(include_missing: false))
+
+          service.execute.then do |result|
+            status result.status
           end
         end
 

spec/factories/ci/build_pending_states.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :ci_build_pending_state, class: 'Ci::BuildPendingState' do
+    build factory: :ci_build
+    trace_checksum { 'crc32:12345678' }
+    state { 'success' }
+  end
+end

spec/models/ci/build_trace_chunk_spec.rb

@@ -463,6 +463,8 @@ RSpec.describe Ci::BuildTraceChunk, :clean_gitlab_redis_shared_state do
   end
 
   describe '#persist_data!' do
+    let(:build) { create(:ci_build, :running) }
+
     subject { build_trace_chunk.persist_data! }
 
     shared_examples_for 'Atomic operation' do
@@ -524,6 +526,18 @@ RSpec.describe Ci::BuildTraceChunk, :clean_gitlab_redis_shared_state do
             expect(Ci::BuildTraceChunks::Database.new.data(build_trace_chunk)).to be_nil
             expect(Ci::BuildTraceChunks::Fog.new.data(build_trace_chunk)).to be_nil
           end
+
+          context 'when chunk is a final one' do
+            before do
+              create(:ci_build_pending_state, build: build)
+            end
+
+            it 'persists the data' do
+              subject
+
+              expect(build_trace_chunk.fog?).to be_truthy
+            end
+          end
         end
       end
 
@@ -573,6 +587,18 @@ RSpec.describe Ci::BuildTraceChunk, :clean_gitlab_redis_shared_state do
             expect(Ci::BuildTraceChunks::Database.new.data(build_trace_chunk)).to eq(data)
             expect(Ci::BuildTraceChunks::Fog.new.data(build_trace_chunk)).to be_nil
           end
+
+          context 'when chunk is a final one' do
+            before do
+              create(:ci_build_pending_state, build: build)
+            end
+
+            it 'persists the data' do
+              subject
+
+              expect(build_trace_chunk.fog?).to be_truthy
+            end
+          end
         end
       end
 
@@ -622,6 +648,54 @@ RSpec.describe Ci::BuildTraceChunk, :clean_gitlab_redis_shared_state do
     end
   end
 
+  describe 'final?' do
+    let(:build) { create(:ci_build, :running) }
+
+    context 'when build pending state exists' do
+      before do
+        create(:ci_build_pending_state, build: build)
+      end
+
+      context 'when chunks is not the last one' do
+        before do
+          create(:ci_build_trace_chunk, chunk_index: 1, build: build)
+        end
+
+        it 'is not a final chunk' do
+          expect(build.reload.pending_state).to be_present
+          expect(build_trace_chunk).not_to be_final
+        end
+      end
+
+      context 'when chunks is the last one' do
+        it 'is a final chunk' do
+          expect(build.reload.pending_state).to be_present
+          expect(build_trace_chunk).to be_final
+        end
+      end
+    end
+
+    context 'when build pending state does not exist' do
+      context 'when chunks is not the last one' do
+        before do
+          create(:ci_build_trace_chunk, chunk_index: 1, build: build)
+        end
+
+        it 'is not a final chunk' do
+          expect(build.reload.pending_state).not_to be_present
+          expect(build_trace_chunk).not_to be_final
+        end
+      end
+
+      context 'when chunks is the last one' do
+        it 'is not a final chunk' do
+          expect(build.reload.pending_state).not_to be_present
+          expect(build_trace_chunk).not_to be_final
+        end
+      end
+    end
+  end
+
   describe 'deletes data in redis after a parent record destroyed' do
     let(:project) { create(:project) }