Hej,

taking another look and comparing it to onion_services exporter there is a slight difference in the metrics output.

prometheus-onion-service-exporter:

onion_service_up{address="foobar:587",name="mail_v3_587",type="tcp"} 1

vs output from tor:

tor_hs_app_write_bytes_total{onion=foobar,port=80} 298891

The working onion-service-exporter double quotes the labels but tor doesn't.

Debug messages from prometheus are also not very helpful:

[...] msg="Append failed" err="expected label value, got "INVALID""

But after searching around for a long time I found that promtool can help with debugging scraping erros.

Promtool complains about the missing double quotes

$ GET http://<IP>:9035/metrics | promtool check metrics error while linting: text format parsing error in line 3: expected '"' at start of label value, found 'f'

Saving the exporter output to a file and quoting the onion and port label values:

$ cat quoted-output.txt | promtool check metrics tor_hs_intro_established_count non-histogram and non-summary metrics should not have "_count" suffix tor_hs_rdv_established_count non-histogram and non-summary metrics should not have "_count" suffix

After removing the criticized "_count" in the file promtool is happy.

So, how to fix this to not make my weekend project fail? Relabel label values!

First try (for testing):

relabel_configs: - action: labeldrop regex: "port" - action: labeldrop regex: "onion"

not working, still 'expected label value, got "INVALID"'. What about:

relabel_configs: - target_label: onion replacement: foo - target_label: port replacement: bar

now I got not only the labels 'instance="<IP>:9035"job="tor_metrics"' but also 'onion="foo" port="bar"' but still the 'expected label value, got "INVALID"' error.

Out of ideas for the moment.

Best fran

On 1/23/22 01:20, Fran wrote:

Hej,

I just found out about the integrated prometheus exporter in tor - yay, thanks for that!

I can scrape it with curl:

$ curl http://<ip>:9035/metrics # HELP tor_hs_rdv_num_total Total number of rendezvous circuit created # TYPE tor_hs_rdv_num_total counter tor_hs_rdv_num_total{onion=<onionv3adr>} 4 # HELP tor_hs_app_write_bytes_total Total number of bytes written to the application # TYPE tor_hs_app_write_bytes_total counter tor_hs_app_write_bytes_total{onion=<onionv3adr>,port=80} 15211 # HELP tor_hs_intro_num_total Total number of introduction received # TYPE tor_hs_intro_num_total counter tor_hs_intro_num_total{onion=<onionv3adr>} 4 # HELP tor_hs_rdv_established_count Total number of established rendezvous circuit # TYPE tor_hs_rdv_established_count gauge tor_hs_rdv_established_count{onion=<onionv3adr>} 1 # HELP tor_hs_app_read_bytes_total Total number of bytes read from the application # TYPE tor_hs_app_read_bytes_total counter tor_hs_app_read_bytes_total{onion=<onionv3adr>,port=80} 319667 # HELP tor_hs_intro_established_count Total number of established introduction circuit # TYPE tor_hs_intro_established_count gauge tor_hs_intro_established_count{onion=<onionv3adr>} 18

Which looks like proper data for me. Unfortunately prometheus thinks otherwise. In the prometheus webGUI under "/targets" it complains:

...

expected label value, got "INVALID"

The Prometheus config part is:

- job_name: tor_metrics     metrics_path: /metrics     static_configs:     - targets:       - <server1>:9035       - <server2>:9035

Servers are running Debian 11, Prometheus 2.32.1 and tor 0.4.6.9-1~d11.bullseye+1

I searched the relays mailinglist and tried to find something in the internet, unfortunately not very successfully.

Any ideas?

Thanks a lot!

fran