feat(bench): self-contained Docker Compose setup

Build benchmark binary inside container via multi-stage
Dockerfile. All-in-one: docker compose run bench.

bench/Dockerfile

@@ -0,0 +1,25 @@
+FROM haskell:9.6.3 AS build
+
+WORKDIR /src
+
+# Copy cabal file first for dependency caching
+COPY simplexmq.cabal cabal.project* ./
+RUN cabal update && cabal build --only-dependencies -f server_postgres smp-server-bench || true
+
+# Copy full source
+COPY . .
+RUN cabal build -f server_postgres smp-server-bench \
+  && cp $(cabal list-bin -f server_postgres smp-server-bench) /usr/local/bin/smp-server-bench
+
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+      libgmp10 libpq5 libffi8 zlib1g ca-certificates \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY --from=build /usr/local/bin/smp-server-bench /usr/local/bin/smp-server-bench
+COPY tests/fixtures /app/tests/fixtures
+
+WORKDIR /app
+
+ENTRYPOINT ["smp-server-bench"]

bench/docker-compose.yml

@@ -5,8 +5,6 @@ services:
       POSTGRES_USER: smp
       POSTGRES_DB: smp_bench
       POSTGRES_HOST_AUTH_METHOD: trust
-    ports:
-      - "15432:5432"
     volumes:
       - ./init.sql:/docker-entrypoint-initdb.d/init.sql
       - pgdata:/var/lib/postgresql/data
@@ -16,5 +14,33 @@ services:
       timeout: 5s
       retries: 10
 
+  bench:
+    build:
+      context: ..
+      dockerfile: bench/Dockerfile
+    depends_on:
+      postgres:
+        condition: service_healthy
+    environment:
+      BENCH_PG: "postgresql://smp@postgres/smp_bench"
+      BENCH_CLIENTS: "${BENCH_CLIENTS:-5000}"
+      BENCH_MINUTES: "${BENCH_MINUTES:-5}"
+    command:
+      - "--pg"
+      - "postgresql://smp@postgres/smp_bench"
+      - "--clients"
+      - "${BENCH_CLIENTS:-5000}"
+      - "--minutes"
+      - "${BENCH_MINUTES:-5}"
+      - "--timeseries"
+      - "/results/timeseries.csv"
+      - "+RTS"
+      - "-N"
+      - "-A16m"
+      - "-T"
+      - "-RTS"
+    volumes:
+      - ./results:/results
+
 volumes:
   pgdata:

bench/run.sh

@@ -2,24 +2,25 @@
 set -e
 cd "$(dirname "$0")"
 
-mkdir -p tmp
+mkdir -p results
 
 reset_db() {
   docker compose down -v 2>/dev/null || true
-  docker compose up -d --wait
+  docker compose up -d --wait postgres
   echo "PostgreSQL ready."
 }
 
 if [ "$1" = "--compare-rts" ]; then
   shift
+  docker compose build bench
   for label_flags in \
-    "default:-N -A16m -s" \
-    "F1.2:-N -A16m -F1.2 -s" \
-    "F1.5:-N -A16m -F1.5 -s" \
-    "A4m:-N -A4m -s" \
-    "A4m-F1.2:-N -A4m -F1.2 -s" \
-    "compact:-N -A16m -c -s" \
-    "nonmoving:-N -A16m -xn -s"; do
+    "default:-N -A16m -T" \
+    "F1.2:-N -A16m -F1.2 -T" \
+    "F1.5:-N -A16m -F1.5 -T" \
+    "A4m:-N -A4m -T" \
+    "A4m-F1.2:-N -A4m -F1.2 -T" \
+    "compact:-N -A16m -c -T" \
+    "nonmoving:-N -A16m -xn -T"; do
     label="${label_flags%%:*}"
     flags="${label_flags#*:}"
     echo ""
@@ -27,22 +28,33 @@ if [ "$1" = "--compare-rts" ]; then
     echo "  RTS config: $label ($flags)"
     echo "=========================================="
     reset_db
-    cabal run smp-server-bench -- \
-      --timeseries "bench-${label}.csv" \
+    docker compose run --rm \
+      -e BENCH_CLIENTS="${BENCH_CLIENTS:-1000}" \
+      -e BENCH_MINUTES="${BENCH_MINUTES:-2}" \
+      bench \
+      --pg "postgresql://smp@postgres/smp_bench" \
       --clients "${BENCH_CLIENTS:-1000}" \
       --minutes "${BENCH_MINUTES:-2}" \
+      --timeseries "/results/bench-${label}.csv" \
       "$@" \
       +RTS $flags -RTS
   done
   echo ""
-  echo "Done. CSV files: bench-*.csv"
-else
+  echo "Done. Results in bench/results/"
+elif [ "$1" = "--local" ]; then
+  # Run natively (not in container) — requires local Postgres
+  shift
   reset_db
-  cabal run smp-server-bench -- \
+  cabal run smp-server-bench -f server_postgres -- \
+    --pg "postgresql://smp@localhost:15432/smp_bench" \
     --clients "${BENCH_CLIENTS:-5000}" \
     --minutes "${BENCH_MINUTES:-5}" \
     "$@" \
     +RTS -N -A16m -s -RTS
+else
+  # Run fully in containers
+  reset_db
+  docker compose run --rm bench "$@"
 fi
 
 docker compose down