prometheus-p1-exporter

Prometheus P1 exporter

Prometheus exporter for smart meter statistics fetched from a P1 meter. It supports multiple data sources, including USB Serial P1 cables and the HomeWizard P1 Meter API (v2).

Installation

With Go install:

go install github.com/loafoe/prometheus-p1-exporter@latest

Container Image

OCI images are available via GitHub Container Registry (GHCR). They are multi-arch (linux/amd64, linux/arm64) and signed with cosign.

docker pull ghcr.io/loafoe/prometheus-p1-exporter:latest

Example usage with Docker:

docker run -d \
  --name p1-exporter \
  -p 8888:8888 \
  ghcr.io/loafoe/prometheus-p1-exporter:latest \
  -source=homewizard \
  -homewizard-url=https://192.168.1.100

Usage

Usage of ./prometheus-p1-exporter:
  -listen string
        Listen address for HTTP metrics (default "127.0.0.1:8888")
  -source string
        Source of data: 'serial' (P1 USB) or 'homewizard' (HomeWizard P1 meter API) (default "serial")
  -usb-device string
        USB device for serial source (default "/dev/ttyUSB0")
  -homewizard-url string
        Base URL for HomeWizard API (e.g. https://192.168.1.100)
  -homewizard-token string
        Token for HomeWizard API (v2)
  -homewizard-token-file string
        File to store/read the HomeWizard token (default "homewizard_token.txt")
  -homewizard-interval duration
        Interval for HomeWizard API polling (default 5s)
  -verbose
        Verbose output logging

Data Sources

USB Serial (-source=serial)

This is the default source. It reads directly from a P1 cable connected to your smart meter. It uses the /dev/ttyUSB0 device by default.

HomeWizard P1 Meter (-source=homewizard)

This source polls the HomeWizard P1 Meter local API using the v2 protocol (HTTPS).

Authorization: The HomeWizard v2 API requires a Bearer Token. If no token is provided:

1. The exporter will initiate an authorization request.
2. It will log a warning: Action required: Press the physical button on your HomeWizard device NOW.
3. You have 30 seconds to physically press the button on your HomeWizard P1 Meter.
4. Once authorized, the exporter will save the token to homewizard_token.txt (or the path specified by -homewizard-token-file) so it can be reused across restarts.

Metrics

The exporter provides the following metrics (prefixed with p1_):

Development

The project is structured with a Source interface, making it easy to add new data collection backends.

type Source interface {
    Start(ctx context.Context) (<-chan Reading, error)
}

Grafana Agent

On my Raspberry Pi, I'm running Grafana Agent which ships the metrics to a cloud-based Prometheus instance. Example config below:

metrics:
  global:
    scrape_interval: 2s
    external_labels:
      environment: p1-server
  configs:
    - name: default
      scrape_configs:
        - job_name: 'p1_exporter'
          static_configs:
            - targets: ['localhost:8888']
      remote_write:
        - url: https://prometheus.example.com/api/v1/write
          basic_auth:
            username: scraper
            password: S0m3pAssW0rdH3Re

Acknowledgement

This was forked from jordyv/prometheus-p1-exporter and modified for continuous readouts and multiple source support.