[tor-bugs] #30006 [Applications/Quality Assurance and Testing]: Monitor "aliveness" of default bridges in Tor Browser

[Tor Bug Tracker & Wiki]

#30006: Monitor "aliveness" of default bridges in Tor Browser
-------------------------------------------------+-------------------------
 Reporter:  phw                                  |          Owner:  phw
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  Medium                               |      Milestone:
Component:  Applications/Quality Assurance and   |        Version:
  Testing                                        |
 Severity:  Normal                               |     Resolution:
 Keywords:  default bridge                       |  Actual Points:
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by anarcat):

 also, I researched how the blackbox exporter works and it seems like
 actual blackbox exporter would be actually null: everything happens on the
 prometheus side, as the targets are passed to the exporter from there.

 the `scrape_config` would look something like this:

 {{{
 scrape_configs:
   - job_name: blackbox_tor_bridges
     scrape_interval: 15s
     metrics_path: /probe
     params:
       module: [tcp_connect]
     static_configs:
       - targets:
         - 169.229.59.74:31493
         - 169.229.59.75:46328
         # ...
     relabel_configs:
       - source_labels: [__address__]
         target_label: __param_target
       - source_labels: [__param_target]
         target_label: instance
       - target_label: __address__
         replacement: 127.0.0.1:9115  # The blackbox exporter's real
 hostname:port.
 }}}

 the `targets` line is the tricky part to get right. I think we *might* be
 able to get away with a `file_sd_config` the same way we did for the
 `node_exporter` stuff, with something like this:

 {{{
     # ...
     metrics_path: /probe
     params:
       module: [tcp_connect]
     file_sd_configs:
     - files:
       - "/etc/prometheus/file_sd_config.d/blackbox_tor_bridge_*.yaml"
     relabel_configs:
     # ...
 }}}


 ... instead of `static_config`. Each `blackbox_tor_bridge` file would be
 generated dynamically with a cronjob, which is why it would be critical
 that it's safe to drink from that file, because wrong data might crash the
 Prometheus server or worse.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/30006#comment:4>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online