Hi there,
I looked at our escaping functions for logs due to the need of doing
JSON logging. In principle one can output JSON by using appropriate log
format definitions in the httpd config. Most special characters in JSON
are already properly escaped in our output.
But there is one important difference between the escaping of access log
items and of error log items. The escaping function for the access log
also escapes double quotation marks as \", the one for the error log
does not (ap_escape_errorlog_item). It contains the comment "no need for
this in error log". This is true all the way since the time the escaping
was introduced at all.
I wonder, whether there is a real necessity for not escaping double
quotation marks in the error log?
Note, that I am not talking about markup that appears in the definition
of the ErrorLogFormat itself. This is "just" about double quotation
marks showing up in the error message itself (or logged headers, env
vars or notes).
Unfortunately the use of ap_escape_errorlog_item() is buried deep down
in the code levels and accessing virtual host config seems not possible,
not even in the callers of ap_escape_errorlog_item().
If there's no other nice idea, I wonder whether:
- it would be OK, to escape double quotation marks as \" in the error
log for trunk
- add a global config item to do this as well for 2.4.x (default off)
What do you think? Or did you find a better solution for error log json
logging?
Best regards,
Rainer
I looked at our escaping functions for logs due to the need of doing
JSON logging. In principle one can output JSON by using appropriate log
format definitions in the httpd config. Most special characters in JSON
are already properly escaped in our output.
But there is one important difference between the escaping of access log
items and of error log items. The escaping function for the access log
also escapes double quotation marks as \", the one for the error log
does not (ap_escape_errorlog_item). It contains the comment "no need for
this in error log". This is true all the way since the time the escaping
was introduced at all.
I wonder, whether there is a real necessity for not escaping double
quotation marks in the error log?
Note, that I am not talking about markup that appears in the definition
of the ErrorLogFormat itself. This is "just" about double quotation
marks showing up in the error message itself (or logged headers, env
vars or notes).
Unfortunately the use of ap_escape_errorlog_item() is buried deep down
in the code levels and accessing virtual host config seems not possible,
not even in the callers of ap_escape_errorlog_item().
If there's no other nice idea, I wonder whether:
- it would be OK, to escape double quotation marks as \" in the error
log for trunk
- add a global config item to do this as well for 2.4.x (default off)
What do you think? Or did you find a better solution for error log json
logging?
Best regards,
Rainer