Default /metrics route does not support specifying auth_module

[OscarVanL]

mysqld_exporter version: output of mysqld_exporter --version

v0.15.1

MySQL server version

MySQL v5.7, v8.0, also MariaDB 10.7

mysqld_exporter command line flags

--config.my-cnf=/etc/mysql/conf.d/mysqld-exporter.cnf

What did you do that produced an error?

I have followed the docs to setup multi-target support.

The use-case is that I have lots of MySQL/MariaDB servers and do not want to reuse the same username/password across them all.

To achieve this, I have created multiple auth modules in the config file, then created multiple prometheus jobs each using a different auth_module for all the target(s) where those credentials apply.

However, it does not operate as the docs suggest and continues to only use the default client auth_module for all targets.

As a result, authentication fails to my instances.

What did you expect to see?

The specified auth_module should be utilised on the /metrics route for the target database instance.

What did you see instead?

There appears to be one of the following:

• Incorrect documentation
• A bug in the /metrics path that does not exist in the /probe path

Either the documentation does not mention that the the value metrics_path: /probe must be set on the prometheus config (overriding the default /metrics), or there is a bug that /metrics does not utilise the provided auth_module param.

[Sam-Sundar]

Hey @OscarVanL,

Can you share your scrape config ? I too have similar issue, where /probe is not being scrapped and instead /metrics is being scraped which is nothing but exporter's metrics and not the SQL's metrics.

[OscarVanL]

@Sam-Sundar

I modified my prometheus scrape config to look like this:

  - job_name: mysqld-exporter
    metrics_path: /probe
    params:
      auth_module: [client.dev]
    static_configs:
      - targets:
          - 'my-db:3306'
    relabel_configs:
      - source_labels: [__address__]
        target_label: __param_target
      - source_labels: [__param_target]
        target_label: instance
      - target_label: __address__
        replacement: localhost:9104

Specifically adding the metrics_path: /probe line made it scrape the correct path.

[Sam-Sundar]

Hey @OscarVanL ,

i tried this and still it didn't work. Attaching one more issue link below, please point me where i'm making the mistake ?

#812

[OscarVanL]

I couldn't be sure @Sam-Sundar. I'm not an expert with this project, and your setup looks far more complicated than mine.

[Belgarioz]

Hello @OscarVanL ,
I am having the same problem: no matter the value in auth_module, it always take the default [client] section.
Have you found a solution?