scrutiny/docs/TROUBLESHOOTING_REVERSE_PROXY.md

Reverse Proxy Support

Scrutiny is designed so that it can be used with a reverse proxy, leveraging domain, port or path based matching to correctly route to the Scrutiny service.

For simple domain and/or port based routing, this is easy.

If your domain:port pair is similar to http://scrutiny.example.com or http://localhost:54321, just update your reverse proxy configuration to route traffic to the Scrutiny backend, which is listening on 0.0.0.0:8080 by default.

# default config
web:
  listen:
    port: 8080
    host: 0.0.0.0

However if you're using path based routing to differentiate your reverse proxy protected services, things become more complicated.

If you'd like to access Scrutiny using a path like: http://example.com/scrutiny/, then we need a way to configure Scrutiny so that it understands http://example.com/scrutiny/api/health actually means http://localhost:8080/api/health.

Thankfully this can be done by changing two settings (both are required).

1. The webserver has a web.listen.basepath key
2. The collectors have a api.endpoint key.

Webserver Configuration

When setting the web.listen.basepath key in the web config file, make sure the basepath key is prefixed with /.

# customized webserver config
web:
  listen:
    port: 8080
    host: 0.0.0.0
    # if you're using a reverse proxy like apache/nginx, you can override this value to serve scrutiny on a subpath.
    # eg. http://example.com/custombasepath/* vs http://example.com:8080
    basepath: '/custombasepath'

Collector Configuration

Here's how you can update the collector api.endpoint key:

# customized collector config
api:
  endpoint: 'http://localhost:8080/custombasepath'

Environmental Variables.

You may also configure these values using the following environmental variables (both are required).

• COLLECTOR_API_ENDPOINT=http://localhost:8080/custombasepath
• SCRUTINY_WEB_LISTEN_BASEPATH=/custombasepath

Real Examples

Caddy

1. Create a Caddyfile

   # Caddyfile
   :9090
   
   # The `scrutiny` text in this file must match the service name in the docker-compose file below. 
   # The `/custom/` text is the custom base path scrutiny will be availble on. 
   reverse_proxy /custom/* scrutiny:8080
   
   

2. Create a docker-compose.yml file

   # docker-compose.yml
   version: '3.5'
   
   services:
     scrutiny:
       container_name: scrutiny
       image: ghcr.io/analogj/scrutiny:master-omnibus
       cap_add:
         - SYS_RAWIO
       ports:
         - "8086:8086" # influxDB admin
       volumes:
         - /run/udev:/run/udev:ro
         - ./config:/opt/scrutiny/config
         - ./influxdb:/opt/scrutiny/influxdb
       devices:
         - "/dev/sda"
         - "/dev/sdb"
       environment:
         - SCRUTINY_WEB_LISTEN_BASEPATH=/custom
         - COLLECTOR_API_ENDPOINT=http://localhost:8080/custom
     caddy:
       image: caddy
       volumes:
         - ./Caddyfile:/etc/caddy/Caddyfile
       ports:
         - "9090:9090"
   

3. run docker-compose up

4. visit http://localhost:9090/custom/web - access the scrutiny container via caddy reverse proxy