# I built a lightweight Docker container monitor that notifies you alerts

> Source: <https://github.com/PizzukaTorph/compose-watchdog>
> Published: 2026-07-01 07:24:30+00:00

Lightweight Docker container health monitor. Watches all containers on the host and sends notifications via Telegram, Email, and/or Webhook when a container goes down or recovers.

- Monitors all containers via Docker socket (no agent needed)
- Detects
`exited`

,`dead`

, and`unhealthy`

states - Recovery detection: notifies when a container comes back up
- Cooldown to avoid notification spam
- Optional label filter to watch only specific containers
- Config via YAML file or environment variables
- Runs as a Docker container with minimal footprint

```
cp config.example.yml config.yml
# Edit config.yml with your notifier credentials

docker compose up -d --build
```

Config file is loaded from `/config/config.yml`

inside the container (mount your local `config.yml`

).

All values can also be set via environment variables (see `docker-compose.yml`

).

| Key | Default | Description |
|---|---|---|
`interval` |
`30` |
Seconds between checks |
`cooldown` |
`300` |
Seconds before re-notifying same container |
`label_filter` |
— | Only watch containers with this label |

- Open Telegram and search for
**@BotFather** - Send
`/newbot`

and follow the prompts to choose a name and username (must end in`bot`

) - BotFather will reply with your
**token**— copy it into your config

**Finding your chat ID:**

- Send any message to your bot
- Open in browser:
`https://api.telegram.org/bot<TOKEN>/getUpdates`

- If the result is empty (
`"result":[]`

), it means the bot hasn't received any messages yet — go to Telegram, open the bot, press**Start** or send a message, then reload the URL - Look for
`"chat":{"id": 123456789}`

in the JSON — that number is your`chat_id`

Standard SMTP. Works with any provider (Gmail, Mailgun, your own server, etc.).

Sends a POST request with a JSON payload:

...

...

```
npm install
npm run dev
```

Requires Docker socket access on the host.

MIT

If you find this project useful, consider buying me a coffee: