diff --git a/.gitignore b/.gitignore
index cb81e89..e1382ad 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 xo-install.log
+xo-install.cfg
 tests/*/*
 tests/*
 !tests/Ubuntu
diff --git a/README.md b/README.md
index 004fbbe..017bd31 100644
--- a/README.md
+++ b/README.md
@@ -84,7 +84,7 @@ Tool has been tested to work with following distros:
 In order to use file level restore from delta backups, the service needs to be ran as root.
 CentOS installation is currently not able to do file level restore if the backed up disk contains LVM.
 
-CentOS setup is confirmed to work with fresh minimal installation and SELinux enabled. 
+CentOS setup is confirmed to work with fresh minimal installation and SELinux enabled.
 Although script doesn't do any SELinux checks or modifications, so you need to take care of possible changes by yourself according to your system.
 
 Tool makes all necessary changes required for Xen-Orchestra to run (including packages, user creation, permissions). Please evaluate script if needed.
diff --git a/docker/monit-services b/docker/monit-services
index 3dfaf5a..65dc448 100644
--- a/docker/monit-services
+++ b/docker/monit-services
@@ -10,5 +10,5 @@ check process redis with pidfile /var/run/redis_6379.pid
 	stop program = "/usr/bin/redis-cli shutdown"
 
 check process rpcbind
-    matching "rpcbind"
-    start program = "/usr/sbin/rpcbind"
+	matching "rpcbind"
+	start program = "/usr/sbin/rpcbind"
diff --git a/sample.xo-install.cfg b/sample.xo-install.cfg
new file mode 100644
index 0000000..16195c3
--- /dev/null
+++ b/sample.xo-install.cfg
@@ -0,0 +1,28 @@
+# Optional user that runs the service. root by default
+#XOUSER="node"
+
+# Port number where xen-orchestra service is bound
+PORT="80"
+
+# Base dir for installation and future updates
+INSTALLDIR="/etc/xo"
+
+# Git branch or tag (append tags/ before the tag name) where xen-orchestra sources are fetched.
+# Also, you can set this to "release" to use the latest tagged branch.
+BRANCH="master"
+
+# Log path for possible errors
+LOGFILE="$(dirname $0)/xo-install.log"
+
+# comma separated list of plugins to be installed, check README for more information
+#PLUGINS="xo-server-transport-email,xo-server-usage-report,xo-server-perf-alert"
+
+# NodeJS and Yarn are automatically updated when running update. Switch this option to false if you want to disable it.
+AUTOUPDATE="true"
+
+# Define the number of previous installations you want to keep. Needs to be at least 1
+PRESERVE="3"
+
+# X.509 certificate setup.
+PATH_TO_HTTPS_CERT=
+PATH_TO_HTTPS_KEY=
diff --git a/tests/run-tests.sh b/tests/run-tests.sh
index 48138ad..bc72ce7 100755
--- a/tests/run-tests.sh
+++ b/tests/run-tests.sh
@@ -18,24 +18,24 @@ function RunTestsSingle {
 	curl -s -L 192.168.33.101 >> $LOGFILE 2>&1 || false
 
 	if [[ $? == "1" ]]; then
-	echo "$1 install HTTP Check: failed"
+		echo "$1 install HTTP Check: failed"
 	else
 		echo "$1 install HTTP Check: success"
 	fi
 	sleep 5
 
 	vagrant provision --provision-with update >> $LOGFILE 2>&1
-        sleep 5
-        echo "" >> $LOGFILE
-        echo "Curl output after update:" >> $LOGFILE
-        curl -s -L 192.168.33.101 >> $LOGFILE 2>&1 || false
+	sleep 5
+	echo "" >> $LOGFILE
+	echo "Curl output after update:" >> $LOGFILE
+	curl -s -L 192.168.33.101 >> $LOGFILE 2>&1 || false
 
-        if [[ $? == "1" ]]; then
-        echo "$1 update HTTP Check: failed"
-        else
-                echo "$1 update HTTP Check: success"
-        fi
-        sleep 5
+	if [[ $? == "1" ]]; then
+		echo "$1 update HTTP Check: failed"
+	else
+		echo "$1 update HTTP Check: success"
+	fi
+	sleep 5
 
 	vagrant destroy -f >> $LOGFILE 2>&1
 	unset VAGRANT_CWD
@@ -54,13 +54,13 @@ for x in CentOS Debian Ubuntu; do
 		echo "Vagrant box failed to start, exiting"
 		exit 1;
 	fi
-	
+
 	vagrant provision --provision-with install >> $LOGFILE 2>&1
 	sleep 5
 	echo "" >> $LOGFILE
 	echo "Curl output after install:" >> $LOGFILE
 	curl -s -L -m 5 192.168.33.101 >> $LOGFILE 2>&1 || false
-	
+
 	if [[ $? == "1" ]]; then
 		echo "$x install HTTP Check: failed"
 	else
diff --git a/xo-install.sh b/xo-install.sh
index 716c2a7..be2b8df 100755
--- a/xo-install.sh
+++ b/xo-install.sh
@@ -6,33 +6,26 @@
 # Repository: https://github.com/ronivay/XenOrchestraInstallerUpdater   #
 #########################################################################
 
-### Start of editable variables ###
+SAMPLE_CONFIG_FILE="sample.xo-install.cfg"
+CONFIG_FILE="xo-install.cfg"
 
-# Optional user that runs the service. root by default
-#XOUSER="node"
+# Deploy default configuration file if the user doesn't have their own yet.
+if [[ ! -e "$CONFIG_FILE" ]]; then
+	cp $SAMPLE_CONFIG_FILE $CONFIG_FILE
+fi
 
-# Port number where xen-orchestra service is bound
-PORT="80"
+# See this file for all script configuration variables.
+source $CONFIG_FILE
 
-# Base dir for installation and future updates
-INSTALLDIR="/etc/xo"
+XO_SRC_DIR="$INSTALLDIR/xo-src/xen-orchestra"
 
-# Git branch or tag (append tags/ before the tag name) where xen-orchestra sources are fetched
-BRANCH="master"
-
-# Log path for possible errors
-LOGFILE="$(dirname $0)/xo-install.log"
-
-# comma separated list of plugins to be installed, check README for more information
-#PLUGINS="xo-server-transport-email,xo-server-usage-report,xo-server-perf-alert"
-
-# NodeJS and Yarn are automatically updated when running update. Switch this option to false if you want to disable it.
-AUTOUPDATE="true"
-
-# Define the number of previous installations you want to keep. Needs to be at least 1
-PRESERVE="3"
-
-### End of editable variables ###
+# Protocol to use for webserver. If both of the X.509 certificate files exist,
+# then assume that we want to enable HTTPS for the server.
+if [[ -e $PATH_TO_HTTPS_CERT ]] && [[ -e $PATH_TO_HTTPS_KEY ]]; then
+	HTTPS=true
+else
+	HTTPS=false
+fi
 
 function CheckUser {
 
@@ -120,7 +113,7 @@ function InstallDependenciesDebian {
 	trap ErrorHandling ERR INT
 
 	# Install necessary dependencies for XO build
-        
+
 	echo
 	echo -n "Running apt-get update..."
 	apt-get update >/dev/null
@@ -178,8 +171,8 @@ function InstallDependenciesDebian {
 	echo "Enabling and starting redis service"
 	/bin/systemctl enable redis-server >/dev/null && /bin/systemctl start redis-server >/dev/null
 
-        echo "Enabling and starting rpcbind service"
-        /bin/systemctl enable rpcbind >/dev/null && /bin/systemctl start rpcbind >/dev/null
+	echo "Enabling and starting rpcbind service"
+	/bin/systemctl enable rpcbind >/dev/null && /bin/systemctl start rpcbind >/dev/null
 
 } 2>$LOGFILE
 
@@ -203,9 +196,9 @@ function UpdateNodeYarn {
 function InstallXOPlugins {
 
 	set -e
-	
+
 	trap ErrorHandling ERR INT
-	
+
 	if [[ "$PLUGINS" ]] && [[ ! -z "$PLUGINS" ]]; then
 
 		echo
@@ -255,16 +248,37 @@ function InstallXO {
 		mkdir -p "$INSTALLDIR"
 	fi
 
+	echo
+	echo "Fetching Xen Orchestra source code ..."
+	echo
+	if [[ ! -d "$XO_SRC_DIR" ]]; then
+		mkdir -p "$XO_SRC_DIR"
+		git clone https://github.com/vatesfr/xen-orchestra "$XO_SRC_DIR"
+	else
+		cd "$XO_SRC_DIR"
+		git pull
+		cd $(dirname $0)
+	fi
+
+	# Deploy the latest xen-orchestra source to the new install directory.
 	echo
 	echo "Creating install directory: $INSTALLDIR/xo-builds/xen-orchestra-$TIME"
-	mkdir -p "$INSTALLDIR/xo-builds/xen-orchestra-$TIME"
+	rm -rf "$INSTALLDIR/xo-builds/xen-orchestra-$TIME"
+	cp -r "$XO_SRC_DIR" "$INSTALLDIR/xo-builds/xen-orchestra-$TIME"
 
-	echo
-	echo "Fetching source code from branch: $BRANCH ..."
-	echo
-	git clone https://github.com/vatesfr/xen-orchestra $INSTALLDIR/xo-builds/xen-orchestra-$TIME
+	if [[ "$BRANCH" == "release" ]]; then
+		cd $INSTALLDIR/xo-builds/xen-orchestra-$TIME
+		TAG=$(git describe --tags $(git rev-list --tags --max-count=1))
+
+		echo
+		echo "Checking out latest tagged release '$TAG'"
+
+		git checkout $TAG 2> /dev/null  # Suppress the detached-head message.
+		cd $(dirname $0)
+	elif [[ "$BRANCH" != "master" ]]; then
+		echo
+		echo "Checking out source code from branch '$BRANCH'"
 
-	if [[ "$BRANCH" != "master" ]]; then
 		cd $INSTALLDIR/xo-builds/xen-orchestra-$TIME
 		git checkout $BRANCH
 		cd $(dirname $0)
@@ -273,6 +287,54 @@ function InstallXO {
 	echo
 	echo "done"
 
+	# Check if the new repo is any different from the currently-installed
+	# one. If not, then skip the build and delete the repo we just cloned.
+
+	# Get the commit ID of the to-be-installed xen-orchestra.
+	cd $INSTALLDIR/xo-builds/xen-orchestra-$TIME
+	NEW_REPO_HASH=$(git rev-parse HEAD)
+	NEW_REPO_HASH_SHORT=$(git rev-parse --short HEAD)
+	cd $(dirname $0)
+
+	# Get the commit ID of the currently-installed xen-orchestra (if one
+	# exists).
+	if [[ -L $INSTALLDIR/xo-server ]]; then
+		cd $INSTALLDIR/xo-server
+		OLD_REPO_HASH=$(git rev-parse HEAD)
+		OLD_REPO_HASH_SHORT=$(git rev-parse --short HEAD)
+		cd $(dirname $0)
+	else
+		# If there's no existing installation, then we definitely want
+		# to proceed with the bulid.
+		OLD_REPO_HASH=""
+		OLD_REPO_HASH_SHORT=""
+	fi
+
+	# If the new install is no different from the existing install, then don't
+	# proceed with the build.
+	if [[ "$NEW_REPO_HASH" == "$OLD_REPO_HASH" ]]; then
+		echo
+		echo "No changes to xen-orchestra since previous install. Skipping xo-server and xo-web build."
+		echo "Cleaning up install directory: $INSTALLDIR/xo-builds/xen-orchestra-$TIME"
+		rm -rf $INSTALLDIR/xo-builds/xen-orchestra-$TIME
+		return 0
+	fi
+
+	# Now that we know we're going to be building a new xen-orchestra, make
+	# sure there's no already-running xo-server process.
+	if [[ $(ps aux | grep xo-server | grep -v grep) ]]; then
+		echo
+		echo -n "Shutting down xo-server..."
+		/bin/systemctl stop xo-server || { echo "failed to stop service, exiting..." ; exit 1; }
+		echo "done"
+	fi
+
+	# If this isn't a fresh install, then list the upgrade the user is making.
+	if [[ ! -z "$OLD_REPO_HASH" ]]; then
+		echo
+		echo "Updating xen-orchestra from '$OLD_REPO_HASH_SHORT' to '$NEW_REPO_HASH_SHORT'"
+	fi
+
 	echo
 	echo "xo-server and xo-web build quite a while. Grab a cup of coffee and lay back"
 	echo
@@ -320,6 +382,14 @@ function InstallXO {
 		sleep 2
 	fi
 
+	if $HTTPS ; then
+		echo "Enabling HTTPS in xo-server configuration file"
+		sed -i "s%#   cert: '.\/certificate.pem'%  cert: '$PATH_TO_HTTPS_CERT'%" $INSTALLDIR/xo-builds/xen-orchestra-$TIME/packages/xo-server/sample.config.yaml
+		sed -i "s%#   key: '.\/key.pem'%  key: '$PATH_TO_HTTPS_KEY'%" $INSTALLDIR/xo-builds/xen-orchestra-$TIME/packages/xo-server/sample.config.yaml
+		sed -i "s/#redirectToHttps/redirectToHttps/" $INSTALLDIR/xo-builds/xen-orchestra-$TIME/packages/xo-server/sample.config.yaml
+		sleep 2
+	fi
+
 	echo "Activating modified configuration file"
 	mv $INSTALLDIR/xo-builds/xen-orchestra-$TIME/packages/xo-server/sample.config.yaml $INSTALLDIR/xo-builds/xen-orchestra-$TIME/packages/xo-server/.xo-server.yaml
 
@@ -363,13 +433,13 @@ function InstallXO {
 	set +x
 
 	timeout 60 bash <<-"EOF"
-		while [[ -z $(journalctl -u xo-server | sed -n 'H; /Starting XO Server/h; ${g;p;}' | grep "http:\/\/\[::\]:$PORT") ]]; do
+		while [[ -z $(journalctl -u xo-server | sed -n 'H; /Starting XO Server/h; ${g;p;}' | grep "https\{0,1\}:\/\/\[::\]:$PORT") ]]; do
 			echo "waiting port to be open"
 			sleep 10
 		done
 	EOF
 
-	if [[ $(journalctl -u xo-server | sed -n 'H; /Starting XO Server/h; ${g;p;}' | grep "http:\/\/\[::\]:$PORT") ]]; then
+	if [[ $(journalctl -u xo-server | sed -n 'H; /Starting XO Server/h; ${g;p;}' | grep "https\{0,1\}:\/\/\[::\]:$PORT") ]]; then
 		echo
 		echo "WebUI started in port $PORT"
 		echo "Default username: admin@admin.net password: admin"
@@ -387,13 +457,6 @@ function InstallXO {
 
 function UpdateXO {
 
-	if [[ $(ps aux | grep xo-server | grep -v grep) ]]; then
-		echo
-		echo -n "Shutting down xo-server..."
-		/bin/systemctl stop xo-server || { echo "failed to stop service, exiting..." ; exit 1; }
-		echo "done"
-	fi
-
 	InstallXO
 
 	if [[ "$PRESERVE" != "0" ]]; then
@@ -436,9 +499,9 @@ function HandleArgs {
 			;;
 		esac
 
-}	
+}
 
-function RollBackInstallation {	
+function RollBackInstallation {
 
 	INSTALLATIONS=($(find $INSTALLDIR/xo-builds/ -maxdepth 1 -type d -name "xen-orchestra-*"))
 
@@ -643,7 +706,7 @@ read -p ": " option
 					;;
 					2)
 						PullDockerImage
-						
+
 					;;
 					3)
 						exit 0