[1] Proposed title of this feature request

-> Loki: max_line_size_truncate configuration option

 [2] What is the nature and description of the request?

-> IHAC who is using OpenShift Logging 6 to store our logs in Loki-Stack.
The max_line_size is set to 256KB by default in loki.
So every message above 256KB is discarded. It would be better for us not to discard log messages. There is an option in the loki documentation (

https://grafana.com/docs/loki/latest/configure/#limits_config) to truncate the log messages: max_line_size_truncate

Can we configure this option to truncate long log messages rather than discard them?

 [3]Why does the customer need this? (List the business requirements here)

-> The primary problem is that Loki is silently dropping messages if the size (max_line_size) is exceeded. Even though they are able to change the limit, any message exceeding their new limit will still be dropped.
There is an option to let Loki truncate such long lines, rather than dropping them: https://grafana.com/docs/loki/latest/operations/request-validation-rate-limits/#validation-errors and https://grafana.com/docs/enterprise-logs/latest/config/loki-config-reference/#limits_config. Their ask is to get this (commandline?) switch enabled, so that messages are still accepted, but truncated to the max_line_size if they are exceeding that limit. This would developers still see most of a message instead of not seeing any.

 [4] List any affected packages or components.

-> logging, lokistack.