Add the url of this repo to add-on store
Search for the "Prometheus Node Exporter" add-on in the Supervisor add-on store and install it.
Disable "Protection mode" in the add-on panel.
Optional - Check the Configuration tab of the add-on to make any changes you'd like.
Start the add-on.
Check the Logs tab of the add-on to see if everything went well.
To verify the metrics are available, visit http://your_home_assistant_ip_address:9100/metrics in your browser, or use curl: curl -X GET http://your_home_assistant_ip_address:9100/metrics.

Configuration

By default, Prometheus Node Exporter listens on TCP port 9100.

HTTP Basic Authentication

HTTP Basic Auth is disabled by default. If you want to enable HTTP Basic Auth:

set enable_basic_auth to true
enter the basic_auth_user and basic_auth_pass

TLS

TLS is disabled by default. If you want to enable TLS:

set enable_tls to true
enter the cert_file and cert_key

⚠️ Note that the cert_file and cert_key need to be a /path/to/fullchain.pem and /path/to/privkey.pem, respectively (/config and /ssl are mapped to this add-on) ⚠️

Command-line arguments

This option allows you to pass command-line arguments directly to Prometheus Node Exporter. This is particularly useful to adjust which collectors run. For example, to disable all collectors except the cpu collector, you can use this string: --collector.disable-defaults --collector.cpu.

Usage (in Prometheus server)

Add the following to the /etc/prometheus/prometheus.yml config file on your Prometheus server:

scrape_configs:
  ...
  ...
  ...
  - job_name: 'homeassistant'
    static_configs:
    - targets: ['your_home_assistant_ip_address:9100']
    basic_auth:
      username: username_goes_here
      password: password_goes_here

The following Prometheus query should return data:

node_uname_info{job="homeassistant"}