Topic: Apache CustomLog piped to sed

[dimitrov.b]

Hello,

I'm trying to replace a pattern in access log before it is printed into the log file. I've read many articles about this but can't make it working. Tested on two different setups. Both setups were freshly installed with minimal installation and httpd installed after that.

Setup 1 - Centos 6.8 / Apache 2.2.15

CustomLog "|/bin/sed -e 's/888/111/g' >> /var/log/httpd/access_log" combined

Here it is "almost" working. Putting "$" before /bin/sed doesn't change anything. First nothing is printed into the access_log. After performing "apachectl restart" all the queries made before get printed into the log and patern 888 is replaces with 111. Any new queries are not printed until the next restart.


Setup 2 - Centos 7.3 / Apache 2.4.6

Not working at all. Without "$" before /bin/sed I'm getting error that sed can't read file ">>". With "$" there is no error but nothing is printed into access log. After restart still nothing into the log.


Many thanks!

[James Blond]

Apache starts the standard shell to execute the command. For apache 2.2 you can also try || instead of | with the full path to sed

see
https://httpd.apache.org/docs/2.2/logs.html#piped

Yepp the 2.4 piped logs working differently

See

By default the piped log process is spawned without invoking a shell. Use "|$" instead of "|" to spawn using a shell (usually with /bin/sh -c):

So there use the $ in front of the command with the full path to sed

Make sure that sed is working correctly with the shell apache is using.