diff --git a/.gitea/workflows/docker-build.yaml b/.gitea/workflows/docker-build.yaml
index 0be9e70..dd31a7b 100644
--- a/.gitea/workflows/docker-build.yaml
+++ b/.gitea/workflows/docker-build.yaml
@@ -2,45 +2,69 @@ name: Docker Build and Push
 
 on:
   pull_request:
-    branches: [master]
   push:
-    branches: [master]
   schedule:
-    - cron: '0 0 * * *'
+    - cron: '30 3 * * 3'
 
 jobs:
-  build:
+  lint:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+      - name: Hadolint
+        uses: hadolint/hadolint-action@54c9adbab1582c2ef04b2016b760714a4bfde3cf
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v4
+  build:
+    runs-on: ubuntu-latest
+    needs: lint
+    steps:
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+      - name: Build image
+        run: docker build -t ci-image:${{ github.sha }} .
+      - name: Save image
+        run: docker save ci-image:${{ github.sha }} > image.tar
+      - name: Upload artifact
+        uses: ChristopherHX/gitea-upload-artifact@62ac910c5d3dfa85c7cb2df15afe2e342b2407c2
+        with:
+          name: docker-image
+          path: image.tar
 
+  test:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+      - name: Download artifact
+        uses: ChristopherHX/gitea-download-artifact@75635f32b4c1c41c4b3d64e8f85210112ed4c9c7
+        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
+    if: github.event_name != 'pull_request'
+    needs: test
+    steps:
+      - name: Checkout
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10
+      - name: Download artifact
+        uses: ChristopherHX/gitea-download-artifact@75635f32b4c1c41c4b3d64e8f85210112ed4c9c7
+        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
+        uses: docker/login-action@650006c6eb7dba73a995cc03b0b2d7f5ca915bee
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Docker metadata
-        id: meta
-        uses: docker/metadata-action@v6
-        with:
-          images: jcabillot/crond
-          tags: |
-            #type=ref,event=branch
-            #type=ref,event=pr
-            #type=sha
-            type=raw,value=latest,enable=${{ 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/crond:latest
+          docker push jcabillot/crond:latest
diff --git a/Dockerfile b/Dockerfile
index 26b0c2d..1eb00ce 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,16 +1,16 @@
-FROM "alpine:3.23"
+FROM alpine:3.23
 LABEL maintainer="Julien Cabillot <dockerimages@cabillot.eu>"
 
-# Ce projet tourne en root, mais je ne voit pas encore comment l'en empecher.
+# Ce projet tourne en root, mais je ne vois pas encore comment l'en empecher.
 # Par défaut cron doit pouvoir changer de user pour lire chaque crontab.
-# En forcant un user comme guest, même avec un shell cela ne fonctionne pas.
+# En forçant un user comme guest, même avec un shell cela ne fonctionne pas.
 
+# hadolint ignore=DL3018
 RUN apk add --no-cache tini curl
 
 COPY "run.sh" "/"
 
 #ENTRYPOINT [ "/sbin/tini", "--" ]
 CMD [ "/run.sh" ]
-
-HEALTHCHECK --interval="10s" \
-    CMD pgrep crond || exit 1
+HEALTHCHECK --interval=10s \
+    CMD pgrep crond || exit 1
\ No newline at end of file
diff --git a/run.sh b/run.sh
index 76d8205..9200bb1 100755
--- a/run.sh
+++ b/run.sh
@@ -2,5 +2,5 @@
 
 set -o pipefail -o nounset -o errexit
 
-echo "${crond_line}" > "/etc/crontabs/root"
+echo "${crond_line:-}" > "/etc/crontabs/root"
 crond -f -L /dev/stdout
diff --git a/tests/test.sh b/tests/test.sh
new file mode 100644
index 0000000..324e10a
--- /dev/null
+++ b/tests/test.sh
@@ -0,0 +1,34 @@
+#!/bin/bash
+set -euo pipefail
+
+IMAGE="$1"
+FAILED=0
+PASSED=0
+
+TMPDIR="$(mktemp -d)"
+trap 'rm -rf "$TMPDIR"' EXIT
+CONTAINER_NAME="test-crond-$$"
+
+# Test 1: Container starts and crond is running
+docker run -d --name "$CONTAINER_NAME" "$IMAGE"
+sleep 4
+if [ "$(docker inspect "$CONTAINER_NAME" --format='{{.State.Running}}')" != "true" ]; then
+  echo "FAIL: container exited prematurely"
+  echo "=== Container logs ==="
+  docker logs "$CONTAINER_NAME" 2>&1 || true
+  FAILED=$((FAILED + 1))
+elif docker exec "$CONTAINER_NAME" pgrep crond > /dev/null 2>&1; then
+  echo "PASS: crond is running"
+  PASSED=$((PASSED + 1))
+else
+  echo "FAIL: crond is not running"
+  FAILED=$((FAILED + 1))
+fi
+
+docker rm -f "$CONTAINER_NAME" > /dev/null 2>&1 || true
+
+echo ""
+echo "$PASSED/$((PASSED + FAILED)) tests passed"
+if [ "$FAILED" -gt 0 ]; then
+  exit 1
+fi