Apache configuration files

Apache uses a main configuration file in a plain text format which normally then calls other files using Include and IncludeOptional directives for ease of management and separation of concern.

The location of Apache's main configuration file is set during compile time and differ between distributions.

You can always check the location of the configuration file by running the Apache binary for your distribution with the -V option and then look for the SERVER_CONFIG_FILE value.

$ apachectl -V
Server version: Apache/2.4.41 (Unix)
Server built:   Nov  9 2019 07:53:54
Server's Module Magic Number: 20120211:88
Server loaded:  APR 1.5.2, APR-UTIL 1.5.4
Compiled using: APR 1.5.2, APR-UTIL 1.5.4
Architecture:   64-bit
Server MPM:     prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_FLOCK_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=256
 -D HTTPD_ROOT="/usr"
 -D SUEXEC_BIN="/usr/bin/suexec"
 -D DEFAULT_PIDLOG="/private/var/run/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="/private/etc/apache2/mime.types"
 -D SERVER_CONFIG_FILE="/private/etc/apache2/httpd.conf"

Apart from using different location for the main configuration file, different distributions also use different options for Apache which could get a bit confusing.

The table below lists some of the default configuration values for Apache on different distributions.