feat: add web dashboard UI for monitoring and managing cron jobs

Dockerfile

@@ -78,7 +78,10 @@ RUN apk update --quiet && \
         su-exec \
         tini \
         wget \
-        shadow && \
+        shadow \
+        python3 \
+        py3-flask \
+        py3-supervisor && \
     rm /var/cache/apk/* && \
     rm -rf /etc/periodic /etc/crontabs/root && \
     # Set SUID on crontab command so it can modify crontab files
@@ -89,11 +92,16 @@ RUN apk update --quiet && \
     (getent group | grep -q ":${DOCKER_GID}:" && addgroup docker || addgroup -g ${DOCKER_GID} docker) && \
     # Create docker user and add to docker group
     adduser -S docker -D -G docker && \
-    mkdir -p ${HOME_DIR}/jobs ${HOME_DIR}/crontabs && \
+    mkdir -p ${HOME_DIR}/jobs ${HOME_DIR}/crontabs ${HOME_DIR}/data && \
     chown -R docker:docker ${HOME_DIR}
 
 COPY --from=builder /usr/bin/rq/rq /usr/local/bin
 COPY entrypoint.sh /opt
+COPY supervisord.conf /opt/crontab/
+COPY webapp/ /opt/crontab/webapp/
+
+# Expose web UI port
+EXPOSE 8080
 
 ENTRYPOINT ["/sbin/tini", "--", "/opt/entrypoint.sh"]
 

README.md

@@ -17,6 +17,124 @@ A great project, don't get me wrong. It was just missing certain key enterprise
 - Run command in a container using `container`.
 - Ability to trigger scripts in other containers on completion cron job using `trigger`.
 - Ability to share settings between cron jobs using `~~shared-settings` as a key.
+- **Web Dashboard UI** for monitoring and controlling cron jobs.
+
+## Web Dashboard
+
+The crontab container includes a built-in web dashboard for monitoring and managing your cron jobs.
+
+### Features
+
+- 📊 **Job Monitoring**: View all scheduled jobs with their current status
+- 📅 **Schedule Information**: See when jobs last ran and when they'll run next
+- 📝 **Execution History**: Browse past executions with timestamps and exit codes
+- 🔍 **Log Viewer**: View stdout and stderr output from job executions
+- ▶️ **Manual Triggering**: Run jobs on-demand with a single click
+- 📈 **Dashboard Stats**: Overview of total jobs, failures, and recent activity
+- 🔄 **Auto-Refresh**: Dashboard automatically updates every 30 seconds
+
+### Accessing the Web UI
+
+The web dashboard is available on port **8080** by default.
+
+**Docker Run:**
+
+```bash
+docker run -d \
+    -v /var/run/docker.sock:/var/run/docker.sock:ro \
+    -v ./config.json:/opt/crontab/config.json:ro \
+    -v crontab-data:/opt/crontab/data \
+    -p 8080:8080 \
+    crontab
+```
+
+Then open http://localhost:8080 in your browser.
+
+**Docker Compose:**
+
+```yaml
+services:
+  crontab:
+    build: .
+    ports:
+      - "8080:8080"
+    volumes:
+      - "/var/run/docker.sock:/var/run/docker.sock:ro"
+      - "./config.json:/opt/crontab/config.json:ro"
+      - "crontab-data:/opt/crontab/data"  # Persistent database
+    environment:
+      - WEB_UI_PORT=8080
+      - JOB_HISTORY_RETENTION_DAYS=30
+      - JOB_HISTORY_RETENTION_COUNT=1000
+
+volumes:
+  crontab-data:
+```
+
+### Configuration
+
+Configure the web UI using environment variables:
+
+| Variable                      | Default | Description                               |
+| ----------------------------- | ------- | ----------------------------------------- |
+| `WEB_UI_PORT`                 | `8080`  | Port for the web dashboard                |
+| `JOB_HISTORY_RETENTION_DAYS`  | `30`    | Keep execution history for this many days |
+| `JOB_HISTORY_RETENTION_COUNT` | `1000`  | Keep at least this many recent executions |
+
+### Data Persistence
+
+Job execution history is stored in a SQLite database at `/opt/crontab/data/crontab.db`. To persist this data across container restarts, mount a volume:
+
+```bash
+-v crontab-data:/opt/crontab/data
+```
+
+### Health Check
+
+The web UI includes a health check endpoint at `/api/health`:
+
+```bash
+curl http://localhost:8080/api/health
+```
+
+Response:
+
+```json
+{
+  "status": "healthy",
+  "crond_running": true,
+  "database_accessible": true,
+  "uptime_seconds": 86400
+}
+```
+
+### API Endpoints
+
+The dashboard exposes a REST API for programmatic access:
+
+- `GET /api/jobs` - List all jobs
+- `GET /api/executions/<job_name>` - Get execution history for a job
+- `POST /api/trigger/<job_name>` - Manually trigger a job
+- `GET /api/stats` - Get dashboard statistics
+- `GET /api/health` - Health check
+
+### Security Considerations
+
+The web UI does **not** include authentication by default. For production deployments:
+
+1. **Reverse Proxy**: Use a reverse proxy (nginx, Traefik) with authentication
+1. **Network Isolation**: Run on a private network, not exposed to the internet
+1. **Firewall Rules**: Restrict access to trusted IP addresses
+
+Example nginx reverse proxy with basic auth:
+
+```nginx
+location /crontab/ {
+    auth_basic "Crontab Dashboard";
+    auth_basic_user_file /etc/nginx/.htpasswd;
+    proxy_pass http://crontab:8080/;
+}
+```
 
 ## Config file
 

docker-compose.yml

@@ -15,6 +15,16 @@ services:
         # Or alternatively: stat -c '%g' /var/run/docker.sock
         DOCKER_GID: 999
     restart: always
+    ports:
+      - "8080:8080"
     volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "${PWD}/config-samples/config.sample.mapping.json:/opt/crontab/config.json:ro"
+     - "crontab-data:/opt/crontab/data"
+    environment:
+      - WEB_UI_PORT=8080
+      - JOB_HISTORY_RETENTION_DAYS=30
+      - JOB_HISTORY_RETENTION_COUNT=1000
+
+volumes:
+  crontab-data:

entrypoint.sh

@@ -190,8 +190,33 @@ function build_crontab() {
             echo "#\!/usr/bin/env bash"
             echo "set -e"
             echo ""
+            echo "JOB_NAME=\"${SCRIPT_NAME}\""
+            echo "TIMESTAMP=\$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+            echo "PID=\$\$"
+            echo ""
+            echo "# Log job start to database"
+            echo "python3 /opt/crontab/webapp/db_logger.py start \"\${JOB_NAME}\" \"\${TIMESTAMP}\" \"cron\" \"\${PID}\" 2>&1 || true"
+            echo ""
+            echo "# Capture output to temp files"
+            echo "STDOUT_FILE=\"/tmp/job-\${JOB_NAME}-\$\$.stdout\""
+            echo "STDERR_FILE=\"/tmp/job-\${JOB_NAME}-\$\$.stderr\""
+            echo ""
             echo "echo \"start cron job __${SCRIPT_NAME}__\""
-            echo "${CRON_COMMAND}"
+            echo "set +e"
+            echo "${CRON_COMMAND} > \"\${STDOUT_FILE}\" 2> \"\${STDERR_FILE}\""
+            echo "EXIT_CODE=\$?"
+            echo "set -e"
+            echo ""
+            echo "# Log job completion to database"
+            echo "END_TIMESTAMP=\$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+            echo "python3 /opt/crontab/webapp/db_logger.py end \"\${JOB_NAME}\" \"\${END_TIMESTAMP}\" \"\${EXIT_CODE}\" \"\${STDOUT_FILE}\" \"\${STDERR_FILE}\" 2>&1 || true"
+            echo ""
+            echo "# Output to container logs"
+            echo "cat \"\${STDOUT_FILE}\" 2>/dev/null || true"
+            echo "cat \"\${STDERR_FILE}\" >&2 2>/dev/null || true"
+            echo ""
+            echo "# Clean up temp files"
+            echo "rm -f \"\${STDOUT_FILE}\" \"\${STDERR_FILE}\""
         }  > "${SCRIPT_PATH}"
 
         TRIGGER=$(echo "${KEY}" | jq -r '.trigger')
@@ -245,6 +270,18 @@ function build_crontab() {
     printf "##### cron running #####\n"
 }
 
+init_webapp() {
+    printf "##### initializing web app #####\n"
+
+    # Initialize database schema
+    python3 /opt/crontab/webapp/init_db.py
+
+    # Sync jobs from config to database
+    python3 /opt/crontab/webapp/sync_jobs.py "${CONFIG}"
+
+    printf "##### web app initialized #####\n"
+}
+
 start_app() {
     normalize_config
     export CONFIG=${HOME_DIR}/config.working.json
@@ -254,6 +291,16 @@ start_app() {
     fi
     if [ "${1}" == "crond" ]; then
         build_crontab
+        init_webapp
+    fi
+
+    # Use supervisord to manage crond and Flask if we're starting crond
+    if [ "${1}" == "crond" ]; then
+        if [ "$(id -u)" = "0" ]; then
+            exec su-exec docker supervisord -c /opt/crontab/supervisord.conf
+        else
+            exec supervisord -c /opt/crontab/supervisord.conf
+        fi
     fi
 
     # Filter out invalid crond flags

supervisord.conf

@@ -0,0 +1,28 @@
+[supervisord]
+nodaemon=true
+user=docker
+logfile=/dev/null
+logfile_maxbytes=0
+loglevel=info
+pidfile=/tmp/supervisord.pid
+
+[program:crond]
+command=crond -f -d 7 -c /opt/crontab/crontabs
+autostart=true
+autorestart=true
+stdout_logfile=/dev/fd/1
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/fd/2
+stderr_logfile_maxbytes=0
+priority=10
+
+[program:flask]
+command=python3 /opt/crontab/webapp/app.py
+autostart=true
+autorestart=true
+stdout_logfile=/dev/fd/1
+stdout_logfile_maxbytes=0
+stderr_logfile=/dev/fd/2
+stderr_logfile_maxbytes=0
+environment=FLASK_ENV="production",WEB_UI_PORT="8080"
+priority=20