Resolved Plesk Grafana errors

[UHolthausen]

Server operating system version

Debian 12.11

Plesk version and microupdate number

Plesk Obsidian 18.0.71 Update 1 Web Pro Edition

Hello

since the last update of Grafana the log( grafana and sys) are full of entries. What causes this?

Grafana itself works without any problems.

Example:

2 00:00:16 server grafana[2462093]: logger=plugin.context t=2025-07-22T00:00:16.00257062+02:00 level=warn msg="Could not create user agent" error="invalid user agent format"
Jul 22 00:00:31 server grafana[2462093]: logger=plugin.context t=2025-07-22T00:00:31.00182883+02:00 level=warn msg="Could not create user agent" error="invalid user agent format"
Jul 22 00:00:32 server grafana[2462093]: logger=plugin.context t=2025-07-22T00:00:32.001197136+02:00 level=warn msg="Could not create user agent" error="invalid user agent format"

 

[Sebahat.hadzhi]

Hello, @UHolthausen . We do have a registered bug on our end identified with ID EXTPLESK-9121. Our team suspects that the root cause might be a bug in Grafana, but the case is currently still under investigation. The workaround, we can suggest is:

1. Open the /etc/grafana/grafana.ini file for editing with vi/nano.
2. Change the value of level from warn to error:
   
   

   [log]
   # Either "console", "file", "syslog". Default is console and  file
   # Use space to separate multiple modes, e.g. "console file"
   ;mode = console file
   
   # Either "debug", "info", "warn", "error", "critical", default is "info"
   level = error

3. Restart Grafana
   

   service grafana-server restart

 

[UHolthausen]

Hello

Thank you for the tip, it worked.

 

[StefanoSudati]

The "plesk-json-backend-datasource" plugin is causing user agent errors.

Grafana Issues Summary​

Primary Issue: Plugin User Agent Format Error​

Error Message:




logger=plugin.context t=2025-08-13T09:22:01.008876738+02:00 level=warn msg="Could not create user agent" error="invalid user agent format"

Details:

• Frequency: Every 2-3 seconds continuously
• Log Location: journalctl -u grafana-server
• Service: grafana-server.service
• Log Level: warn

Root Cause: Problematic Plugins​

Plugin 1: plesk-json-backend-datasource

• Version: 0.9.0
• Status: Unsigned plugin (not officially verified)
• Issue: Malformed HTTP User-Agent header generation

Plugin 2: plesk-end-datasource

• Status: Unsigned plugin
• Issue: Contributing to user agent format errors

Error Pattern Locations​

1. System Journal: /var/log/journal/ (via journalctl -u grafana-server)
2. Grafana Logs: /var/log/grafana/grafana.log
3. Plugin Directory: /var/lib/grafana/plugins/

Impact​

• Functionality: Grafana works normally ✅
• Performance: No performance impact
• Logs: Continuous spam making debugging difficult ⚠️
• Disk Space: Log files growing unnecessarily

Status​

ACTIVE ISSUE - Plugins automatically reinstall when Plesk Grafana extension is installed

 

[AYamshanov]

logger=plugin.context t=2025-08-13T09:22:01.008876738+02:00 level=warn msg="Could not create user agent" error="invalid user agent format"
[...]
Logs: Continuous spam making debugging difficult ⚠️
Disk Space: Log files growing unnecessarily

Hi! It sounds like [11.2.2+security-01] logs : error="invalid user agent format" · Issue #95006 · grafana/grafana.
As a workaround, you can decrease the logging level in /etc/grafana/grafana.ini.

 

[Quentium]

Hello, I am looking for a fix rather than a workaround. Maybe the plesk team can have a look at /var/lib/grafana/plugins/plesk-json-backend-datasource/dist? There is a maintained version of this plugin that proposed as an updated alternative GitHub - simPod/GrafanaJsonDatasource: Grafana datasource to load JSON data over your arbitrary HTTP backend
Thanks

 

[Sebahat.hadzhi]

Thank you for your proposal. I am not an expect, but to me it sounds like that will require significant rework and I doubt that our team will agree to change the whole logic for a bug that can be qualified as cosmetic. Nevertheless, I forwarded your suggestion.

 

[Quentium]

Thank you for your proposal. I am not an expect, but to me it sounds like that will require significant rework and I doubt that our team will agree to change the whole logic for a bug that can be qualified as cosmetic. Nevertheless, I forwarded your suggestion.

Thanks for your message, I think the current plugin has been forked by plesk, so maybe we can keep it and just adjust to fix this spammy error? Would be quicker and non breaking change