valheim-logfilter

Filter Valheim dedicated server log output

Valheim server by default logs a lot of noise. These env variables allow users to remove unwanted lines from the log.

Prefix	Purpose
VALHEIM_LOG_FILTER_EMPTY	Filter empty log lines
VALHEIM_LOG_FILTER_UTF8	Filter invalid UTF8 characters
VALHEIM_LOG_FILTER_MATCH	Filter log lines exactly matching
VALHEIM_LOG_FILTER_STARTSWITH	Filter log lines starting with
VALHEIM_LOG_FILTER_ENDSWITH	Filter log lines ending with
VALHEIM_LOG_FILTER_CONTAINS	Filter log lines containing
VALHEIM_LOG_FILTER_REGEXP	Filter log lines matching regexp

Event hooks

If an environment variable prefixed with ON_ exists for an identically named log filter instead of removing the log line the contents of the variable will be executed when the filter matches with the log line piped on stdin.

Prefix	Purpose
ON_VALHEIM_LOG_FILTER_MATCH	Run command hook on log lines exactly matching
ON_VALHEIM_LOG_FILTER_STARTSWITH	Run command hook on log lines starting with
ON_VALHEIM_LOG_FILTER_ENDSWITH	Run command hook on log lines ending with
ON_VALHEIM_LOG_FILTER_CONTAINS	Run command hook on log lines containing
ON_VALHEIM_LOG_FILTER_REGEXP	Run command hook on regexp match

All environment variables except for VALHEIM_LOG_FILTER_EMPTY and VALHEIM_LOG_FILTER_UTF8 are prefixes. Meaning you can define multiple matches like so:

-e VALHEIM_LOG_FILTER_STARTSWITH=foo \
-e VALHEIM_LOG_FILTER_STARTSWITH_BAR=bar \
-e VALHEIM_LOG_FILTER_STARTSWITH_SOMETHING_ELSE="some other filter"
-e VALHEIM_LOG_FILTER_CONTAINS_Connected="Got character ZDOID from"
-e ON_VALHEIM_LOG_FILTER_CONTAINS_Connected="cat >> /tmp/character_logins"

Usage

Usage of valheim-logfilter:
  -alsologtostderr
    	log to standard error as well as files
  -env-contains string
    	Valheim contains filter varname prefix (default "VALHEIM_LOG_FILTER_CONTAINS")
  -env-empty string
    	Valheim empty-line filter varname (default "VALHEIM_LOG_FILTER_EMPTY")
  -env-endswith string
    	Valheim ends-with filter env varname prefix (default "VALHEIM_LOG_FILTER_ENDSWITH")
  -env-match string
    	Valheim match filter env varname prefix (default "VALHEIM_LOG_FILTER_MATCH")
  -env-regexp string
    	Valheim regexp filter varname prefix (default "VALHEIM_LOG_FILTER_REGEXP")
  -env-startswith string
    	Valheim starts-with filter env varname prefix (default "VALHEIM_LOG_FILTER_STARTSWITH")
  -log_backtrace_at value
    	when logging hits line file:N, emit a stack trace
  -log_dir string
    	If non-empty, write log files in this directory
  -logtostderr
    	log to standard error instead of files
  -stderrthreshold value
    	logs at or above this threshold go to stderr
  -v value
    	log level for V logs
  -vmodule value
    	comma-separated list of pattern=N settings for file-filtered logging