apache update gotcha’s

My Apache environment is pretty heterogeneous. I run Apache in CentOS, and Ubuntu, and several released versions of those linux distros. Oh yea, and also on the Unix based Mac OS X. On a few machines I hand build the Apache stack, and package it up as an rpm. As a result I deal with various Apache configurations versions and releases. Did I mention that I run several virtual environments as well. As a result my apache configurations are all over the place , both literally and figuratively. The other day I discovered this unpleasant apache error message , which actually derailed me for a bit longer than it should have.

AH00526: Syntax error on line 279 of /path/httpd.conf:
Invalid command 'Order', perhaps misspelled or defined by a module not included in 
the server configuration

Whoopse, what the heck happened? After floundering around a bit I found this apache documentation on run-time on the subject. The error message should have screamed you updated your apache doofus [ from 2.2 to 2.4 ]. Then I would have found the Apache upgrade 2.4 – 2.4 guide much quicker.

Once I realized this.. I remembered oh yea.. I updated to saucy … I knew there would be some fallout from that upgrade. After digging into this a bit I made the following changes to my Apache configuration.

1: add the following modules for authz

# mod_authz_default is an old Apache 2.2 module.. remove it.
#LoadModule authz_default_module modules/mod_authz_default.so

# Apache 2.4 additions
LoadModule authz_core_module /usr/lib/apache2/modules/mod_authz_core.so
# Depends: authz_core
LoadModule authz_host_module /usr/lib/apache2/modules/mod_authz_host.so
LoadModule authz_user_module /usr/lib/apache2/modules/mod_authz_user.so
LoadModule authz_groupfile_module /usr/lib/apache2/modules/mod_authz_groupfile.s

2: Modify your configuration options

   # Apache 2.2 configuration
   # MaxClients           90
   # MaxRequestsPerChild   0 

   # Apache 2.4 Configuration
   MaxRequestWorkers    90
   MaxConnectionsPerChild 0

3: Modify your directory configurations

   # Apache 2.2 configuration
   # Order deny,allow
   # Deny from all
   # Apache 2.4 Configuration
   Require all denied

Apache versions this document reference:
Apache/2.2.27 (Unix) –> Apache/2.4.6 (Ubuntu)
I mention this because these are the specific versions that this document is written against. However these configuration attributes should be relevant for any 2.2* and 2.4*. Also I mostly run Apache to support django apps, therefore almost all of my apache configurations are MPM Worker mode.