fix: adding ci tests

Author: starek4

.github/workflows/ci.yml

@@ -187,6 +187,59 @@ jobs:
           name: regression_logs
           path: /tmp/failed/*
 
+      - name: Upload dragonfly binary for cgroup test
+        if: matrix.container == 'ubuntu-dev:24' && matrix.build-type == 'Release' && matrix.sanitizers == 'NoSanitizers' && matrix.compiler.cxx == 'g++'
+        uses: actions/upload-artifact@v7
+        with:
+          name: dragonfly-binary
+          path: ${{ github.workspace }}/build/dragonfly
+          retention-days: 1
+
+  cgroup-thread-detection:
+    runs-on: ubuntu-latest
+    needs: [build]
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/download-artifact@v7
+        with:
+          name: dragonfly-binary
+          path: build
+
+      - name: Test cgroup CPU auto-detection
+        run: |
+          chmod +x build/dragonfly
+
+          # Scenario 1: --cpus=2, no flag -> should auto-detect 2 threads
+          CID=$(docker run --rm -d --cpus=2 --security-opt seccomp=unconfined \
+            -v "$PWD/build/dragonfly:/dragonfly" -p 16380:6379 ubuntu:24.04 \
+            /dragonfly --port 6379 --maxmemory 1G --dbfilename "" --noversion_check)
+
+          for i in $(seq 1 20); do
+            sleep 1
+            redis-cli -p 16380 PING 2>/dev/null | grep -q PONG && break
+          done
+
+          THREADS=$(redis-cli -p 16380 INFO server | grep -oP 'thread_count:\K\d+')
+          docker rm -f "$CID"
+          echo "Scenario 1: expected 2, got $THREADS"
+          [ "$THREADS" -eq 2 ]
+
+          # Scenario 2: --cpus=2 + --proactor_threads=4 -> flag must win
+          CID=$(docker run --rm -d --cpus=2 --security-opt seccomp=unconfined \
+            -v "$PWD/build/dragonfly:/dragonfly" -p 16381:6379 ubuntu:24.04 \
+            /dragonfly --port 6379 --proactor_threads 4 --maxmemory 1G --dbfilename "" --noversion_check)
+
+          for i in $(seq 1 20); do
+            sleep 1
+            redis-cli -p 16381 PING 2>/dev/null | grep -q PONG && break
+          done
+
+          THREADS=$(redis-cli -p 16381 INFO server | grep -oP 'thread_count:\K\d+')
+          docker rm -f "$CID"
+          echo "Scenario 2: expected 4, got $THREADS"
+          [ "$THREADS" -eq 4 ]
+
   lint-test-chart:
     runs-on: ubuntu-latest
     needs: [build]

src/server/dfly_main.cc

@@ -1085,6 +1085,8 @@ Usage: dragonfly [FLAGS]
   // honor it over the cgroup-derived CPU limit. The flag defaults to 0, so any non-zero value
   // means the user explicitly requested a specific thread count.
   if (absl::GetFlag(FLAGS_proactor_threads) > 0) {
+    LOG(INFO) << "Using proactor_threads=" << absl::GetFlag(FLAGS_proactor_threads)
+              << " (overriding cgroup-derived " << max_available_threads << ")";
     max_available_threads = 0;  // causes ProactorPool to use FLAGS_proactor_threads
   }
 #endif

tests/dragonfly/proactor_threads_test.py

@@ -26,9 +26,7 @@ async def test_proactor_threads_flag_is_respected(df_factory: DflyInstanceFactor
 
 
 @pytest.mark.asyncio
-async def test_proactor_threads_env_var_is_respected(
-    df_factory: DflyInstanceFactory, monkeypatch
-):
+async def test_proactor_threads_env_var_is_respected(df_factory: DflyInstanceFactory, monkeypatch):
     """DFLY_proactor_threads env var must behave identically to the CLI flag.
 
     The subprocess inherits the parent environment, so setting the variable here