# 🐳 Docker Guide

Pulse is distributed as a lightweight, Alpine-based Docker image.

> **Paid Pulse Pro / Relay / legacy customers:** The public `rcourtman/pulse`
> Docker image is the community build. It can accept an activation key, but it
> does not include the private Pulse Pro runtime hooks. Use
> <https://pulserelay.pro/download.html> with your activation key, then run the
> private registry login and `PULSE_IMAGE=license.pulserelay.pro/pulse-pro:<version>`
> compose commands shown there. Those commands require the compose file image
> line to use the `PULSE_IMAGE` variable, as shown below. If your compose file
> hardcodes `image: rcourtman/pulse:...`, replace that line with the variable
> form or with the private image shown on the download page before restarting.

## 🚀 Quick Start

```bash
docker run -d \
  --name pulse \
  -p 7655:7655 \
  -v pulse_data:/data \
  -e PULSE_DEPLOYMENT_METHOD=docker_run \
  --restart unless-stopped \
  rcourtman/pulse:vX.Y.Z
```

Access at `http://<your-ip>:7655`.

---

## 📦 Docker Compose

Create a `docker-compose.yml` file:

```yaml
services:
  pulse:
    image: ${PULSE_IMAGE:-rcourtman/pulse:vX.Y.Z}
    container_name: pulse
    restart: unless-stopped
    ports:
      - "7655:7655"
    volumes:
      - pulse_data:/data
    environment:
      - TZ=Europe/London
      - PULSE_DEPLOYMENT_METHOD=docker_compose
      # Optional: Pre-configure auth (skips setup wizard)
      # - PULSE_AUTH_USER=admin
      # - PULSE_AUTH_PASS=secret123

volumes:
  pulse_data:
```

Run with: `docker compose up -d`

The `PULSE_IMAGE` variable lets the same compose file run either the public
community image or, for eligible paid customers, the private Pulse Pro image
shown on <https://pulserelay.pro/download.html>.

---

## ⚙️ Configuration

Pulse is configured via the UI (`system.json`) with optional environment overrides.

| Variable | Description | Default |
|----------|-------------|---------|
| `TZ` | Timezone | `UTC` |
| `PULSE_AUTH_USER` | Admin Username | *(unset)* |
| `PULSE_AUTH_PASS` | Admin Password | *(unset)* |
| `DISCOVERY_SUBNET` | Custom CIDR to scan | *(auto)* |
| `ALLOWED_ORIGINS` | CORS allowed origin (`*` or a single origin). Empty = same-origin only. | *(unset)* |
| `LOG_LEVEL` | Log verbosity (`debug`, `info`, `warn`, `error`) | `info` |
| `PULSE_DISABLE_DOCKER_UPDATE_ACTIONS` | Hide Docker update buttons (read-only mode) | `false` |
| `PULSE_METRICS_DB_PATH` | Optional path for only `metrics.db`, useful with tmpfs | `/data/metrics.db` |
| `PULSE_METRICS_ROLLUP_INTERVAL` | Metrics aggregation cadence; minimum 5 minutes | `15m` |

> **Tip**: Set `LOG_LEVEL=warn` to reduce log volume while still capturing important events.
> **Note**: API tokens are managed in the UI and stored in `api_tokens.json`.
> **Note**: Plain text values in `PULSE_AUTH_PASS` are auto-hashed on startup.

For SSD-sensitive installs, keep `/data` persistent and put only metrics
history on tmpfs:

```yaml
services:
  pulse:
    environment:
      PULSE_METRICS_DB_PATH: /metrics-tmpfs/metrics.db
    tmpfs:
      - /metrics-tmpfs:size=512m,uid=1000,gid=1000,mode=0700
```

Metrics history stored this way is lost on container restart.

<details>
<summary><strong>Advanced: Resource Limits & Healthcheck</strong></summary>

```yaml
services:
  pulse:
    deploy:
      resources:
        limits:
          cpus: '0.5'
          memory: 256M
    healthcheck:
      test: ["CMD", "wget", "--spider", "-q", "http://localhost:7655/api/health"]
      interval: 30s
      timeout: 10s
      retries: 3
```
</details>

---

## 🔄 Updates

To update Pulse to a specific release tag:

```bash
docker pull rcourtman/pulse:vX.Y.Z
docker stop pulse
docker rm pulse
# Re-run your docker run command
```

If using Compose:
```bash
docker compose pull
docker compose up -d
```

---

## 🔄 Docker / Podman Updates

Pulse can detect and apply updates to your Docker / Podman containers directly from the UI.

### How It Works

1. **Update Detection**: Pulse compares the local image digest with the latest digest from the container registry
2. **Visual Indicator**: Containers with available updates show a blue upward arrow icon
3. **Reviewed Update**: Click the update button, approve the reviewed action, and Pulse handles the rest

### Updating a Container

1. Navigate to the **Workloads** page (or filter by Docker sources on **Infrastructure**)
2. Look for containers with a blue update arrow (⬆️)
3. Click the update button and approve the action in the review dialog (admin approval required)
4. Pulse will:
   - Pull the latest image
   - Stop the current container
   - Create a backup (renamed with `_pulse_backup_` suffix)
   - Start a new container with the same configuration
   - Clean up the backup after 15 minutes (if the update succeeds)

### Batch Updates

Updates run as reviewed per-container actions, so there is currently no bulk update flow: update each container individually with its own update button. The **"Update all"** button in the host drawer only points you to the per-container buttons.

### Safety Features

- **Automatic Backup**: The old container is renamed, not deleted, until the update succeeds
- **Rollback on Failure**: If the new container fails to start, the old one is restored
- **Configuration Preserved**: Networks, volumes, ports, environment variables are all preserved

### Requirements

- **Unified agent** running on the Docker host with Docker monitoring enabled
- **Command execution enabled** on the agent (`--enable-commands` or `PULSE_ENABLE_COMMANDS=true`) — updates run as reviewed actions through the agent's command channel, the same as [container lifecycle actions](#️-container-lifecycle-actions), and share their requirements and limitations (admin approval, authorization-plugin block)
- Agent must have Docker socket access (`/var/run/docker.sock`)
- Registry must be accessible for update detection (public registries work automatically)

### Private Registries

For private registries, ensure your Docker daemon has credentials configured:

```bash
docker login registry.example.com
```

The agent uses the Docker daemon's credentials for both pulling images and checking for updates.

Paid Pulse Pro Docker installs use the private Pulse Pro registry rather than
the public `rcourtman/pulse` image. Open <https://pulserelay.pro/download.html>,
paste your activation key, run the Docker login command shown there, then run
the shown `PULSE_IMAGE=license.pulserelay.pro/pulse-pro:<version> docker compose pull`
and `docker compose up -d` commands from the host that already runs Pulse. If
your compose file has a hardcoded `image: rcourtman/pulse:...` line, change it
to `image: ${PULSE_IMAGE:-rcourtman/pulse:vX.Y.Z}` or directly to the private
image shown on the download page before running those commands.

### Disabling Update Features

Pulse provides granular control over update features via environment variables on the **Pulse server**:

| Variable | Description |
|----------|-------------|
| `PULSE_DISABLE_DOCKER_UPDATE_ACTIONS` | Hides update buttons from the UI while still detecting updates. Use this for "read-only" monitoring. |

**Example - Read-Only Mode** (detect updates but prevent actions):
```yaml
services:
  pulse:
    image: ${PULSE_IMAGE:-rcourtman/pulse:vX.Y.Z}
    environment:
      - PULSE_DISABLE_DOCKER_UPDATE_ACTIONS=true
```

To disable registry checks entirely, set `PULSE_DISABLE_DOCKER_UPDATE_CHECKS=true` on the **agent**.

You can also toggle "Hide Docker Update Buttons" from the UI in **Settings → System → General** under **Docker / Podman updates**.

---

## ▶️ Container Lifecycle Actions

Pulse can start, stop, and restart Docker / Podman containers directly from the UI. Running containers offer **stop** and **restart**; stopped containers offer **start**.

### Requirements

- **Pulse Agent** installed on the container host (see [Unified Agent](UNIFIED_AGENT.md)) and currently connected
- **Command execution enabled** on the agent — it is disabled by default. Either:
  - start the agent with `--enable-commands` (or `PULSE_ENABLE_COMMANDS=true`), or
  - tick **Enable Pulse command execution** in **Settings → Infrastructure** before copying the install command, which adds the flag and grants the token the command execution permission
- **Admin approval**: every lifecycle action requires confirmation by an admin in the UI before it runs. The agent then verifies the container's state before the change and confirms it actually reached the requested state afterwards.

### Limitations

- If the Docker daemon has **authorization plugins** configured, Pulse blocks all daemon-mutating commands on that host (see advisory GO-2026-4887) and the lifecycle buttons are not offered. Podman hosts are not affected.
- Actions are unavailable while the host's Docker inventory is stale or the agent is disconnected.

---

## 🛠️ Troubleshooting

- **Forgot Password?**
  ```bash
  docker exec pulse rm /data/.env
  docker restart pulse
  # Access UI again. Pulse will require a bootstrap token for setup.
  # Get it with:
  docker exec pulse /app/pulse bootstrap-token
  ```

- **Logs**
  ```bash
  docker logs -f pulse
  ```

- **Shell Access**
  ```bash
  docker exec -it pulse /bin/sh
  ```