switch-httpd.sh

#!/bin/bash

set -o errexit

# toggles between httpd 2.2.x and 2.4.x

# 2.2.x packages

# httpd.x86_64                         2.2.26-1.1.amzn1              @amzn-updates
# httpd-devel.x86_64                   2.2.26-1.1.amzn1              @amzn-updates
# httpd-tools.x86_64                   2.2.26-1.1.amzn1              @amzn-updates

# 2.4.x packages

# httpd24.x86_64 : Apache HTTP Server
# httpd24-devel.x86_64 : Development interfaces for the Apache HTTP server
# httpd24-tools.x86_64 : Tools for use with the Apache HTTP Server

# === Colour Definitions ===
red='\e[0;31m'
green='\e[0;32m'
purple='\e[0;35m'
orange='\e[0;33m'
# No Color, i.e. turn off color
nc='\e[0m'

# Fail eagerly if run as root.
# from https://gist.github.com/rehevkor5/5145245
if [[ $EUID -eq 0 ]]; then
    echo -e "${red}This script must be run as ec2-user.${nc}" 1>&2
    exit 1
fi

if [ -z "$1" ]
then
    echo -e "${orange}[usage]${nc} ${0} staging ${red}OR${nc} ${0} production"
    exit 2
else
    if [ $1 = "staging" ]
    then
	MACHINE_ENV=staging
    elif [ $1 = "production" ]
    then
	MACHINE_ENV=production
    else	
	echo -e "${orange}[usage]${nc} ${0} staging ${red}OR${nc} ${0} production"
	exit 3
    fi
fi

# directory where httpd config is stored
CONF_STORE="./${MACHINE_ENV}/mobolt-httpd-config"

# check whether apache 2.4.x is present
# [begin] block where errors do not result in an exit
set +o errexit
rpm -qi httpd24 &>/dev/null
# capture the return value of rpm, else it'll be overwritten when set is
# called and returns success
RV=$?
set -o errexit
# [end] block

# if httpd24 is found
if (( ${RV} == 0 )) 
then
    # remove httpd 2.4.x
    echo -e "${orange}[INFO]${green} httpd 2.4.x found${nc}. ${red}Erasing...${nc}"
    # sudo service httpd stop
    sudo yum erase httpd24{,-tools,-devel}
    # install httpd 2.2.x
    echo -e "${orange}[INFO]${green} Installing httpd 2.2.x...${nc}"
    sudo yum install httpd{,-tools,-devel}
    # rebuild passenger module
    echo -e "${orange}[INFO]${green} Building passenger module...${nc}"
    # remove the existing config which references the existing (now useless)
    # passenger module, since the compilation process checks for a sane httpd
    # config
    sudo rm -fv /etc/httpd/conf.d/{app,passenger}.conf
    # initiate build process
    passenger-install-apache2-module 
    # install mobolt config (app.conf, passenger.conf) for apache 2.2.x
    echo -e "${orange}[INFO]${green} Installing MoBolt configuration...${nc}"
    sudo cp -v "${CONF_STORE}"/2.2.x/conf.d/{app,passenger}.conf /etc/httpd/conf.d/
    # bring the apache server up again
    sudo service httpd restart
    exit 0 # only one version toggle required.
fi

# check whether apache 2.2.x is present
# [begin] block where errors do not result in an exit
set +o errexit
rpm -qi httpd &>/dev/null
# capture the return value of rpm, else it'll be overwritten when set is
# called and returns success
RV=$?
set -o errexit
# [end] block

# if httpd is found
if (( ${RV} == 0 )) 
then
    # remove httpd 2.2.x
    echo -e "${orange}[INFO]${green} httpd 2.2.x found${nc}. ${red}Erasing...${nc}"
    # sudo service httpd stop
    sudo yum erase httpd{,-tools,-devel}
    # install httpd 2.4.x
    echo -e "${orange}[INFO]${green} Installing httpd 2.4.x...${nc}"
    sudo yum install httpd24{,-tools,-devel}
    # rebuild passenger module
    echo -e "${orange}[INFO]${green} Building passenger module...${nc}"
    # remove the existing config which references the existing (now useless)
    # passenger module, since the compilation process checks for a sane httpd
    # config
    sudo rm -fv /etc/httpd/conf.d/{app,passenger}.conf
    # initiate build process
    passenger-install-apache2-module
    # install mobolt config (app.conf, passenger.conf) for apache 2.4.x
    echo -e "${orange}[INFO]${green} Installing MoBolt configuration...${nc}"
    sudo cp -v "${CONF_STORE}"/2.4.x/conf.d/{app,passenger}.conf /etc/httpd/conf.d/
    # bring the apache server up again
    sudo service httpd restart
fi