# Uncloud Prometheus, part II


Had some fun playing with my [fork of Uncloud](https://github.com/miekg/uncloudplus/). And making metrics
work. Various things don't work out of the box, but can be _made_ to work. For one Prometheus seems to insist
on SRV records, and can't do DNS service discovery with plan A or AAAA records.

... So...

First we need to work around the fact that DNS sd doesn't work, so fake it using file sd:

~~~yaml
  prom_sd_config:
    content: |
      #!/bin/ash
      while true; do
        nslookup m.internal | awk '/^Address:/ && $2 !~ /:/ {if(!seen){print "- targets:"; seen=1} print "  - " $2 ":51004"}' > /prometheus/
uncloud.yaml
        nslookup caddy.internal | awk '/^Address:/ && $2 !~ /:/ {if(!seen){print "- targets:"; seen=1} print "  - " $2 ":9180"}' > /promethe
us/caddy.yaml
        sleep 3600
      done
~~~

This config puts a shell script in place which is then used by a service:

~~~yaml
 unprom-sd:
    image: prom/prometheus
    configs:
      - source: prom_sd_config
        target: /sd_uncloud
        mode: 0770
    volumes:
      - prom_data:/prometheus
    entrypoint: /sd_uncloud
~~~

In prometheus we then use:

```yaml
     - job_name: uncloud
        file_sd_configs:
        - files:
          - /prometheus/uncloud.yaml
      - job_name: caddy
        file_sd_configs:
        - files:
          - /prometheus/caddy.yaml
```

To pick it up. Problem 1 solved.

Problem 2: caddy metrics... in the `x-caddy` file we deploy for Caddy add:
```caddyfile
   metrics {
        per_host
   }
```
But this serves metrics on localhost inside the container. So we need to export this, we can't add this
snippet:
```yaml
     http://:9180 {
          handle {
              metrics
          }
      }
```
Because this is something that does not belong in the global block.

So, we add another service that only adds this:
```yaml
services:
  caddy-metrics:
    image: registry.science.ru.nl/cncz/sys/image/debug:v0.1.14
    x-caddy: |
      http://:9180 {
          handle {
              metrics
          }
      }
```
And deploy this do-nothing-but-update-caddy service. And voila, we have metrics *finally*.