# mqtt2prometheus Helm Chart

This Helm chart deploys mqtt2prometheus to Kubernetes.

## Configuration

### Application Configuration

The mqtt2prometheus configuration can be specified directly in the `values.yaml` file under the `config` section. This configuration will be automatically mounted at `/config.yaml` in the pod.

Example configuration:

```yaml
config:
  mqtt:
    server: tcp://mqtt-broker:1883
    user: myuser
    password: mypassword
    topic_path: sensors/+/data
    qos: 0
  cache:
    timeout: 24h
  json_parsing:
    separator: .
  metrics:
    - prom_name: temperature
      mqtt_name: temperature
      help: Temperature reading
      type: gauge
      const_labels:
        sensor_type: dht22
```

For a complete configuration example, see `config.yaml.dist` in the repository root.

### Installation

Install the chart with:

```bash
helm install my-mqtt2prometheus ./helm \
  --set config.mqtt.server=tcp://your-mqtt-broker:1883 \
  --set config.mqtt.topic_path=your/topic/+
```

Or create a custom `values.yaml` file and install with:

```bash
helm install my-mqtt2prometheus ./helm -f my-values.yaml
```

### Upgrading

To upgrade an existing release:

```bash
helm upgrade my-mqtt2prometheus ./helm -f my-values.yaml
```

## Additional Volumes

You can mount additional volumes (e.g., for TLS certificates) using the `volumes` and `volumeMounts` fields:

```yaml
volumes:
  - name: certs
    secret:
      secretName: mqtt-certs

volumeMounts:
  - name: certs
    mountPath: /certs
    readOnly: true
```

Then reference them in your config:

```yaml
config:
  mqtt:
    server: tcp://mqtt-broker:8883
    ca_cert: /certs/ca.pem
    client_cert: /certs/client.pem
    client_key: /certs/client-key.pem
```

## Prometheus ServiceMonitor

This chart supports creating a ServiceMonitor resource for the [Prometheus Operator](https://github.com/prometheus-operator/prometheus-operator), which enables automatic service discovery and scraping of metrics.

The metrics endpoint is exposed on port 9641 by default (configurable via `service.port`).

### Enable ServiceMonitor

To enable the ServiceMonitor:

```yaml
serviceMonitor:
  enabled: true
```

### Customize ServiceMonitor

You can customize various aspects of the ServiceMonitor:

```yaml
serviceMonitor:
  enabled: true
  # Add custom labels (useful for Prometheus selectors)
  labels:
    prometheus: kube-prometheus
  # Scrape interval
  interval: 30s
  # Scrape timeout
  scrapeTimeout: 10s
  # Metrics path
  path: /metrics
```

### Installing with ServiceMonitor

```bash
helm install my-mqtt2prometheus ./helm \
  --set serviceMonitor.enabled=true \
  --set serviceMonitor.labels.prometheus=kube-prometheus
```

**Note:** The ServiceMonitor resource requires the Prometheus Operator to be installed in your cluster. If you're not using Prometheus Operator, you can configure Prometheus to scrape the service directly using standard Kubernetes service discovery.