From d1433e025e475086bfca2c351aad6c547d6661ca Mon Sep 17 00:00:00 2001
From: ronivay <roni@vayrynen.info>
Date: Mon, 19 Jul 2021 13:12:30 +0300
Subject: [PATCH] comment appliance import script

---
 xo-appliance.sh | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/xo-appliance.sh b/xo-appliance.sh
index 7b3954a..31f1af5 100755
--- a/xo-appliance.sh
+++ b/xo-appliance.sh
@@ -6,6 +6,7 @@
 # Repository: https://github.com/ronivay/XenOrchestraInstallerUpdater   #
 #########################################################################
 
+# image url is static and not configurable by user
 IMAGE_URL="https://xo-appliance.yawn.fi/downloads/image.xva.gz"
 
 function OSCheck {
@@ -30,6 +31,7 @@ function NetworkChoose {
 
 	set +e
 
+	# get network name/uuid of all available networks configured in the pool
 	# shellcheck disable=SC1117
 	IFS=$'\n' read -r -d '' -a networks <<< "$(xe network-list | grep "uuid\|name-label" | cut -d':' -f2 | sed 's/^ //' | paste - -)"
 
@@ -39,11 +41,14 @@ function NetworkChoose {
 	local PS3="Pick a number. CTRL+C to exit: "
 	select network in "${networks[@]}"
 	do
+		# get only the network uuid from array which we need later on when adding vif
 		read -r -a network_split <<< "$network"
 		networkuuid=${network_split[0]}
 
+		# print a menu where to choose network from
 		case $network in
 			*)
+			# save network uuid for later
 			vifuuid="$networkuuid"
 			break
 			;;
@@ -56,9 +61,11 @@ function StorageChoose {
 
 	set +e
 
+	# get storage name/uuid of all available storages with content-type=user which should match all usable storage repositories
 	# shellcheck disable=SC1117
 	IFS=$'\n' read -r -d '' -a storages <<< "$(xe sr-list content-type=user | grep "uuid\|name-description" | cut -d':' -f2 | sed 's/^ //' | paste - -)"
 
+	# bail out if no storage repositories are found
 	if [[ ${#storages[@]} -eq 0 ]]; then
 		echo "No storage repositories found, can't import VM"
 		echo "Create SR and try again. More information: https://xcp-ng.org/docs/storage.html"
@@ -71,15 +78,19 @@ function StorageChoose {
 	local PS3="Pick a number. CTRL+C to exit: "
 	select storage in "${storages[@]}" "default"
 	do
+		# get only the storage repository uuid which we need later on when importing image
 		read -r	-a storage_split <<< "$storage"
 		storageuuid=${storage_split[0]}
 
+		# print a menu where to choose storage from
 		case $storage in
 			default)
+			# this value is handled during import if set to default
 			sruuid=default
 			break
 			;;
 			*)
+			# save storage uuid for later
 			sruuid=$storageuuid
 			break
 			;;
@@ -98,10 +109,13 @@ function NetworkSettings {
 	echo "Set network settings for VM. Leave IP-address as blank to use DHCP"
 	echo
 
+	# read ip address from user input. dhcp is default if left empty
 	read -r -p "IP address: " ipaddress
 	ipaddress=${ipaddress:-dhcp}
 
+	# if not using dhcp, we need more information
 	if [[ "$ipaddress" != "dhcp" ]]; then
+		# get network details from user and prompt again if input doesn't match ip address regex
 		while ! [[ $ipaddress =~ $ipregex ]]; do
 			echo "Check IP address format"
 			read -r -p "IP address: " ipaddress
@@ -139,12 +153,14 @@ function VMImport {
 	echo
 
 	# Import image. We pipe through zcat because xe vm-import should transparently decompress gzipped image, but doesn't seem to understand when stream ends when piped through curl/wget whatnot.
+	# if SR was not defined, we leave that parameter out
 	if [[ $sruuid == "default" ]]; then
 		uuid=$(curl "$IMAGE_URL" | zcat | xe vm-import filename=/dev/stdin)
 	else
 		uuid=$(curl "$IMAGE_URL" | zcat | xe vm-import filename=/dev/stdin sr-uuid="$sruuid")
 	fi
 
+	# exit if import failed for any reason
 	# shellcheck disable=SC2181
 	if [[ $? != "0" ]]; then
 		echo "Import failed"
@@ -153,12 +169,15 @@ function VMImport {
 	echo
 	echo "Import complete"
 
+	# no network interface included in the image, we need to create one based on network uuid set by user earlier
 	xe vif-create network-uuid="$vifuuid" vm-uuid="$uuid" device=0 >/dev/null
 
+	# VM startup script reads network details from xenstore and configures interface based on that so set values based on user input earlier
 	if [[ "$ipaddress" != "dhcp" ]]; then
 		xe vm-param-set uuid="$uuid" xenstore-data:vm-data/ip="$ipaddress" xenstore-data:vm-data/netmask="$netmask" xenstore-data:vm-data/gateway="$gateway" xenstore-data:vm-data/dns="$dns"
 	fi
 
+	# remove all other boot options except disk to speed startup
 	xe vm-param-remove uuid="$uuid" param-name=HVM-boot-params param-key=order
 	xe vm-param-set uuid="$uuid" HVM-boot-params:"order=c"
 
@@ -168,6 +187,7 @@ function VMImport {
 
 	set +e
 
+	# loop max 300 seconds for VM to startup and xen tools to announce ip-address value
 	count=0
 	limit=10
 	ip=$(xe vm-param-get uuid="$uuid" param-name=networks param-key=0/ip 2>/dev/null)
@@ -178,6 +198,7 @@ function VMImport {
 		(( count++ ))
 	done
 
+	# network details are needed in xenstore only during first startup so remove them at this point since VM should be running
 	if [[ "$ipaddress" != "dhcp" ]]; then
 		xe vm-param-remove param-name=xenstore-data param-key=vm-data/ip uuid="$uuid" 2>/dev/null
 		xe vm-param-remove param-name=xenstore-data param-key=vm-data/netmask uuid="$uuid" 2>/dev/null
@@ -185,6 +206,7 @@ function VMImport {
 		xe vm-param-remove param-name=xenstore-data param-key=vm-data/dns uuid="$uuid" 2>/dev/null
 	fi
 
+	# if we got ip-address value from VM, we print how to access it...
 	if [[ "$ip" != "" ]]; then
 		echo
 		echo "VM Started successfully"
@@ -194,6 +216,7 @@ function VMImport {
 		echo "Default credentials for SSH: xo/xopass"
 		echo
 		echo "Remember to change both passwords before putting VM to use!"
+	# ... and print the same without ip-address information if ip-address value was missing
 	else
 		echo
 		echo "VM started but we couldn't fetch it's ip-address from xentools"
@@ -207,6 +230,7 @@ function VMImport {
 
 }
 
+# run all functions in a specific order
 OSCheck
 StorageChoose
 NetworkChoose