From 0ab14d2764d255b9e2736476309605264721721f Mon Sep 17 00:00:00 2001
From: Guilhem Moulin <guilhem@fripost.org>
Date: Sat, 23 Nov 2013 19:02:34 +0100
Subject: Refactored 'virt' shell script.

---
 virtualenv/virt | 58 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/virtualenv/virt b/virtualenv/virt
index 043589f..06b7642 100755
--- a/virtualenv/virt
+++ b/virtualenv/virt
@@ -8,6 +8,7 @@
 #
 
 set -ue
+PATH=/usr/bin:/bin
 root=$(dirname "$0")
 
 usage() {
@@ -22,22 +23,29 @@ usage() {
     exit 1
 }
 
-get_XML_attribute() {
-    local domain="$1" object="$2" attribute="$3"
+getXMLattr() {
+    local id="$1" object="$2" attribute="$3" what="${4:-domain}"
 
-    /usr/bin/virsh dumpxml "$domain" \
-    | /usr/bin/xmlstarlet sel -t -m /domain/"$object" -v @"$attribute"
+    local cmd
+    case "$what" in
+        domain)  cmd=;;
+        network) cmd=net;;
+    esac
+
+    virsh "${cmd:+$cmd-}dumpxml" "$id" \
+    | xmlstarlet sel -t -m "/$what/$object" -n -v @"$attribute" \
+    | sed '/^\s*$/d'
 }
 add_net_section() {
-    local net="${3:-$network}" section="$1" xml="$2"
-    /usr/bin/virsh net-update "$net" add "$section" --xml "$xml" --live --config
+    local section="$1" xml="$2" net="${3:-$network}"
+    virsh net-update "$net" add "$section" --xml "$xml" --live --config
 }
 
 doesExist() {
-    /usr/bin/virsh -r list --all --name | grep -qxF "$1"
+    virsh -r list --all --name | grep -qxF "$1"
 }
 isActive() {
-    /usr/bin/virsh -r list       --name | grep -qxF "$1"
+    virsh -r list       --name | grep -qxF "$1"
 }
 
 install() {
@@ -45,12 +53,13 @@ install() {
     local name=$1
     local disk=${2:-$root/images/${name}.qcow2}
 
-    local darch version=$(sed -n 's/^VERSION\s*=\s*//p' $root/../preseed/Makefile)
+    local darch
     case "${ARCH:=$(/bin/uname -m)}" in
         i386|i686) darch=i386;;
         x86_64)    darch=amd64;;
         *)         darch=$ARCH;;
     esac
+    local version=$(sed -n '/^VERSION\s*=\s*/ {s///p;q}' $root/../preseed/Makefile)
     local cdrom="$root/../preseed/dist/$darch/debian-$version-$darch-netinst-preseeded.iso"
 
     if doesExist "$name"; then
@@ -73,45 +82,38 @@ install() {
 
     grep -q '^kvm\s' /proc/modules || echo 'WARN: KVM not available!' >&2
 
-    if ! [ -r "$disk" -a -r "$disk" ]; then
+    if [ ! -f "$disk" ]; then
         local size=12G
         echo "Creating (sparse) $size disk image '$disk'" >&2
-        /usr/bin/qemu-img create -f "${disk##*.}" \
-            -o size="$size",preallocation=metadata "$disk"
+        qemu-img create -f "${disk##*.}" -o size="$size",preallocation=metadata "$disk"
     fi
 
     # TODO: the bus should be chosen at random among sata,ide,scsi,usb
     # TODO: test EFI: http://www.linux-kvm.org/page/OVMF
-    local network=default
-    /usr/bin/virt-install -q \
+    local network=default ip mac
+    virt-install -q \
         --name      "$name" \
         --arch      "$ARCH" \
         --ram       128 \
         --cdrom     "$cdrom" \
         --disk      "$disk",cache=writeback,bus=sata \
-        --network   network=$network \
+        --network   network="$network" \
         --graphics  spice
 
     # Attribute the next available IP. You may also want to add a domain
     # section, e.g., <domain name='libvirt.example.org'/>, and prepend
     # the DNS IP to /etc/resolv.conf.
     # Cf. http://libvirt.org/formatnetwork.html
-    local mac ip
-    mac=$(get_XML_attribute "$name" devices/interface/mac address)
-    ip=$( /usr/bin/virsh net-dumpxml $network \
-        | /usr/bin/xmlstarlet sel -t -m /network/ip/dhcp/host -n -v @ip \
-        | sed '/^\s*$/d' \
-        | sort -n \
-        | tail -1 )
+    mac=$( getXMLattr $name devices/interface/mac address )
+    ip=$( getXMLattr $network ip/dhcp/host ip network | sort -n | tail -1 )
     [ "$ip" ] || \
-    ip=$( /usr/bin/virsh net-dumpxml $network \
-        | /usr/bin/xmlstarlet sel -t -m /network/ip -v @address )
+    ip=$( getXMLattr $network ip address network )
     ip=${ip%.*}.$(( 1 + ${ip##*.} ))
     add_net_section ip-dhcp-host "<host mac='$mac' name='$name' ip='$ip'/>"
     add_net_section dns-host     "<host ip='$ip'><hostname>$name</hostname></host>"
 
     cat >&2 <<- EOF
-		Domain '$name' has been created, and has been attributed the IP $ip.
+		Domain '$name' has been created, and has been given IP $ip.
 		As you can see in
 
 		    virsh list
@@ -138,14 +140,14 @@ view(){
         exit 1
     fi
 
-    local type=$(get_XML_attribute "$domain" devices/graphics type)
-    local port=$(get_XML_attribute "$domain" devices/graphics port) || true
+    local type=$(getXMLattr "$domain" devices/graphics type)
+    local port=$(getXMLattr "$domain" devices/graphics port) || true
 
     if ! [ "$type" = spice -a "$port" ]; then
         echo "Error: Could not find a valid Spice server on domain '$domain'." >&2
         exit 1
     fi
-    /usr/bin/spicec -h 127.0.0.1 -p $port
+    spicec -h 127.0.0.1 -p $port
 }
 
 [ $# -gt 0 ] || usage
-- 
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