diff --git a/.gitea/workflows/docker-build.yaml b/.gitea/workflows/docker-build.yaml
index 0a2f2cd..e4edc04 100644
--- a/.gitea/workflows/docker-build.yaml
+++ b/.gitea/workflows/docker-build.yaml
@@ -9,38 +9,74 @@ on:
     - cron: '0 0 * * *'
 
 jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Hadolint
+        uses: hadolint/hadolint-action@v3.1.0
+        with:
+          dockerfile: Dockerfile
+
   build:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v6
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v4
+      - name: Build image
+        run: docker build -t ci-image:${{ github.sha }} .
+
+      - name: Save image
+        run: docker save -o image.tar ci-image:${{ github.sha }}
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: docker-image
+          path: image.tar
+          retention-days: 1
+
+  test:
+    runs-on: ubuntu-latest
+    needs: [lint, build]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: docker-image
+
+      - name: Load image
+        run: docker load < image.tar
+
+      - name: Run tests
+        run: bash tests/test.sh ci-image:${{ github.sha }}
+
+  push:
+    runs-on: ubuntu-latest
+    needs: test
+    if: github.event_name != 'pull_request'
+    steps:
+      - name: Download artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: docker-image
+
+      - name: Load image
+        run: docker load < image.tar
 
       - name: Login to Docker Hub
-        if: github.event_name != 'pull_request'
         uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
-      - name: Docker metadata
-        id: meta
-        uses: docker/metadata-action@v6
-        with:
-          images: jcabillot/ip
-          tags: |
-            #type=ref,event=branch
-            #type=ref,event=pr
-            #type=sha
-            type=raw,value=latest,enable=${{ github.ref == 'refs/heads/master' }}
-
-      - name: Build and push
-        uses: docker/build-push-action@v7
-        with:
-          context: .
-          push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}
-          pull: true
+      - name: Tag and push
+        run: |
+          docker tag ci-image:${{ github.sha }} jcabillot/ip:latest
+          docker push jcabillot/ip:latest
diff --git a/tests/test.sh b/tests/test.sh
new file mode 100755
index 0000000..8e84e47
--- /dev/null
+++ b/tests/test.sh
@@ -0,0 +1,72 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+IMAGE="${1:?Usage: test.sh <image>}"
+CONTAINER_NAME="test-$(basename "$IMAGE")-$$"
+PASSED=0
+FAILED=0
+TOTAL=0
+
+cleanup() {
+  docker rm -f "$CONTAINER_NAME" >/dev/null 2>&1 || true
+}
+trap cleanup EXIT
+
+assert() {
+  local name="$1" expected="$2" actual="$3"
+  TOTAL=$((TOTAL + 1))
+  if [ "$expected" = "$actual" ]; then
+    echo "  PASS: $name"
+    PASSED=$((PASSED + 1))
+  else
+    echo "  FAIL: $name (expected: '$expected', got: '$actual')"
+    FAILED=$((FAILED + 1))
+  fi
+}
+
+assert_match() {
+  local name="$1" pattern="$2" actual="$3"
+  TOTAL=$((TOTAL + 1))
+  if echo "$actual" | grep -qE "$pattern"; then
+    echo "  PASS: $name"
+    PASSED=$((PASSED + 1))
+  else
+    echo "  FAIL: $name (pattern: '$pattern', got: '$actual')"
+    FAILED=$((FAILED + 1))
+  fi
+}
+
+echo "Running container: $IMAGE"
+docker run -d --name "$CONTAINER_NAME" -p 0:8080 "$IMAGE" >/dev/null
+
+HOST_PORT=$(docker port "$CONTAINER_NAME" 8080/tcp | head -1 | cut -d: -f2)
+BASE_URL="http://127.0.0.1:${HOST_PORT}"
+
+echo "Waiting for container (port $HOST_PORT)..."
+for i in $(seq 1 30); do
+  if curl -sf "$BASE_URL/" >/dev/null 2>&1; then
+    echo "Container ready after ${i}s"
+    break
+  fi
+  if [ "$i" -eq 30 ]; then
+    echo "FAIL: Container did not become ready within 30s"
+    docker logs "$CONTAINER_NAME"
+    exit 1
+  fi
+  sleep 1
+done
+
+echo ""
+echo "Test: GET /"
+RESPONSE=$(curl -sf -D - "$BASE_URL/")
+STATUS=$(echo "$RESPONSE" | head -1 | grep -oP '\d{3}')
+CONTENT_TYPE=$(echo "$RESPONSE" | grep -i 'content-type' | tr -d '\r' | cut -d: -f2- | xargs)
+BODY=$(echo "$RESPONSE" | tail -1)
+
+assert "HTTP status is 200" "200" "$STATUS"
+assert_match "Content-Type is application/json" "application/json" "$CONTENT_TYPE"
+assert_match "Body contains valid IP" '^(\"[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+\"|\"[0-9a-fA-F:]+\")$' "$BODY"
+
+echo ""
+echo "Results: $PASSED/$TOTAL passed, $FAILED failed"
+[ "$FAILED" -eq 0 ]