#!/bin/bash
 #

 # lib/apache
 # Functions to control configuration and operation of apache web server
 
 # Dependencies:

 #
 # - ``functions`` file

 # - ``STACK_USER`` must be defined
 #

 # lib/apache exports the following functions:
 #

 # - install_apache_wsgi

 # - apache_site_config_for

 # - enable_apache_site
 # - disable_apache_site
 # - start_apache_server
 # - stop_apache_server
 # - restart_apache_server

 
 # Save trace setting

 _XTRACE_LIB_APACHE=$(set +o | grep xtrace)

 set +o xtrace
 
 # Allow overriding the default Apache user and group, default to
 # current user and his default group.

 APACHE_USER=${APACHE_USER:-$STACK_USER}

 APACHE_GROUP=${APACHE_GROUP:-$(id -gn $APACHE_USER)}
 
 
 # Set up apache name and configuration directory
 if is_ubuntu; then
     APACHE_NAME=apache2

     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/sites-available}

 elif is_fedora; then
     APACHE_NAME=httpd

     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/conf.d}

 elif is_suse; then
     APACHE_NAME=apache2

     APACHE_CONF_DIR=${APACHE_CONF_DIR:-/etc/$APACHE_NAME/vhosts.d}

 fi
 
 # Functions
 # ---------
 # install_apache_wsgi() - Install Apache server and wsgi module

 function install_apache_wsgi {

     # Apache installation, because we mark it NOPRIME
     if is_ubuntu; then
         # Install apache2, which is NOPRIME'd
         install_package apache2 libapache2-mod-wsgi

         # WSGI isn't enabled by default, enable it
         sudo a2enmod wsgi

     elif is_fedora; then
         sudo rm -f /etc/httpd/conf.d/000-*
         install_package httpd mod_wsgi
     elif is_suse; then
         install_package apache2 apache2-mod_wsgi

         # WSGI isn't enabled by default, enable it
         sudo a2enmod wsgi

     else
         exit_distro_not_supported "apache installation"
     fi

 
     # ensure mod_version enabled for <IfVersion ...>.  This is
     # built-in statically on anything recent, but precise (2.2)
     # doesn't have it enabled
     sudo a2enmod version || true

 }
 

 # get_apache_version() - return the version of Apache installed
 # This function is used to determine the Apache version installed. There are
 # various differences between Apache 2.2 and 2.4 that warrant special handling.
 function get_apache_version {
     if is_ubuntu; then

         local version_str
         version_str=$(sudo /usr/sbin/apache2ctl -v | awk '/Server version/ {print $3}' | cut -f2 -d/)

     elif is_fedora; then

         local version_str
         version_str=$(rpm -qa --queryformat '%{VERSION}' httpd)

     elif is_suse; then

         local version_str
         version_str=$(rpm -qa --queryformat '%{VERSION}' apache2)

     else
         exit_distro_not_supported "cannot determine apache version"
     fi
     if [[ "$version_str" =~ ^2\.2\. ]]; then
         echo "2.2"
     elif [[ "$version_str" =~ ^2\.4\. ]]; then
         echo "2.4"
     else
         exit_distro_not_supported "apache version not supported"
     fi
 }
 

 # apache_site_config_for() - The filename of the site's configuration file.
 # This function uses the global variables APACHE_NAME and APACHE_CONF_DIR.
 #
 # On Ubuntu 14.04, the site configuration file must have a .conf suffix for a2ensite and a2dissite to
 # recognise it. a2ensite and a2dissite ignore the .conf suffix used as parameter. The default sites'
 # files are 000-default.conf and default-ssl.conf.
 #
 # On Ubuntu 12.04, the site configuration file may have any format, as long as it is in
 # /etc/apache2/sites-available/. a2ensite and a2dissite need the entire file name to work. The default
 # sites' files are default and default-ssl.
 #

 # On Fedora and openSUSE, any file in /etc/httpd/conf.d/ whose name ends with .conf is enabled.

 #
 # On RHEL and CentOS, things should hopefully work as in Fedora.
 #
 # The table below summarizes what should happen on each distribution:
 # +----------------------+--------------------+--------------------------+--------------------------+
 # | Distribution         | File name          | Site enabling command    | Site disabling command   |
 # +----------------------+--------------------+--------------------------+--------------------------+
 # | Ubuntu 12.04         | site               | a2ensite site            | a2dissite site           |
 # | Ubuntu 14.04         | site.conf          | a2ensite site            | a2dissite site           |
 # | Fedora, RHEL, CentOS | site.conf.disabled | mv site.conf{.disabled,} | mv site.conf{,.disabled} |
 # +----------------------+--------------------+--------------------------+--------------------------+
 function apache_site_config_for {
     local site=$@
     if is_ubuntu; then

         local apache_version
         apache_version=$(get_apache_version)

         if [[ "$apache_version" == "2.2" ]]; then

             # Ubuntu 12.04 - Apache 2.2

             echo $APACHE_CONF_DIR/${site}

         else
             # Ubuntu 14.04 - Apache 2.4

             echo $APACHE_CONF_DIR/${site}.conf

         fi

     elif is_fedora || is_suse; then

         # fedora conf.d is only imported if it ends with .conf so this is approx the same

         local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"

         if [ -f $enabled_site_file ]; then
             echo ${enabled_site_file}
         else
             echo ${enabled_site_file}.disabled
         fi
     fi
 }
 

 # enable_apache_site() - Enable a particular apache site

 function enable_apache_site {

     local site=$@
     if is_ubuntu; then
         sudo a2ensite ${site}

     elif is_fedora || is_suse; then

         local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"
         # Do nothing if site already enabled or no site config exists
         if [[ -f ${enabled_site_file}.disabled ]] && [[ ! -f ${enabled_site_file} ]]; then
             sudo mv ${enabled_site_file}.disabled ${enabled_site_file}
         fi

     fi
 }
 
 # disable_apache_site() - Disable a particular apache site

 function disable_apache_site {

     local site=$@
     if is_ubuntu; then
         sudo a2dissite ${site}

     elif is_fedora || is_suse; then

         local enabled_site_file="$APACHE_CONF_DIR/${site}.conf"
         # Do nothing if no site config exists
         if [[ -f ${enabled_site_file} ]]; then
             sudo mv ${enabled_site_file} ${enabled_site_file}.disabled
         fi

     fi
 }
 

 # start_apache_server() - Start running apache server

 function start_apache_server {

     start_service $APACHE_NAME
 }
 
 # stop_apache_server() - Stop running apache server

 function stop_apache_server {

     if [ -n "$APACHE_NAME" ]; then
         stop_service $APACHE_NAME
     else
         exit_distro_not_supported "apache configuration"
     fi
 }
 
 # restart_apache_server

 function restart_apache_server {

     # Apache can be slow to stop, doing an explicit stop, sleep, start helps
     # to mitigate issues where apache will claim a port it's listening on is
     # still in use and fail to start.

     time_start "restart_apache_server"

     stop_service $APACHE_NAME
     sleep 3
     start_service $APACHE_NAME

     time_stop "restart_apache_server"

 }
 
 # Restore xtrace

 $_XTRACE_LIB_APACHE

 # Tell emacs to use shell-script-mode
 ## Local variables:
 ## mode: shell-script
 ## End: