script to install a VM for use as devstack host

virt-install-xenial

#!/bin/bash

## Derives from: http://giovannitorres.me/create-a-linux-lab-on-kvm-using-cloud-images.html

## Assumes you have a xenial cloud image in $DIR below, via e.g.
# wget https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-amd64-disk1.img

# Take one argument from the commandline: VM name
if ! [ $# -eq 1 ]; then
    echo "Usage: $0 <node-name>"
    exit 1
fi

# Check if domain already exists
virsh dominfo $1 > /dev/null 2>&1
if [ "$?" -eq 0 ]; then
    echo -n "[WARNING] $1 already exists.  "
    read -p "Do you want to overwrite $1 (y/[N])? " -r
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        echo ""
        virsh destroy $1 > /dev/null
        virsh undefine $1 > /dev/null
    else
        echo -e "\nNot overwriting $1. Exiting..."
        exit 1
    fi
fi

# Directory to store images
DIR=~/virt/images

# Location of cloud image
IMAGE=$DIR/xenial-server-cloudimg-amd64-disk1.img

# Amount of RAM in MB
MEM=4096

# Number of virtual CPUs
CPUS=1

# Cloud init files
USER_DATA=user-data
META_DATA=meta-data
CI_ISO=$1-cidata.iso
DISK=$1.qcow2

# Bridge for VMs (default on Fedora is virbr0)
BRIDGE=virbr0

# Start clean
rm -rf $DIR/$1
mkdir -p $DIR/$1

pushd $DIR/$1 > /dev/null

    # Create log file
    touch $1.log

    echo "$(date -R) Destroying the $1 domain (if it exists)..."

    # Remove domain with the same name
    virsh destroy $1 >> $1.log 2>&1
    virsh undefine $1 >> $1.log 2>&1

    # cloud-init config: set hostname, remove cloud-init package,
    # and add ssh-key 
    cat > $USER_DATA << _EOF_
#cloud-config

# Hostname management
preserve_hostname: False
hostname: $1
fqdn: $1.example.local

# Remove cloud-init when finished with it
runcmd:
  - [ yum, -y, remove, cloud-init ]

# Configure where output will go
output: 
  all: ">> /var/log/cloud-init.log"

# configure interaction with ssh server
ssh_svcname: ssh
ssh_deletekeys: True
ssh_genkeytypes: ['rsa', 'ecdsa']


# Change this to your own public ssh key!!

# Install my public ssh key to the first user-defined user configured 
# in cloud.cfg in the template (which is centos for CentOS cloud images)
ssh_authorized_keys:
- ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDKdJTIRBb5+u3z11XLCiGqKidQ3gnwAFCReXEv4z5Hx+ghQeE2uEZ4WEIglcEmZ24T3DCmOtBGkej2PXJMGLiauXCiHBhPvAo1+bd1WKoAhXRa7XhTxp4sGc+KGd4E6JaAe3gn4IgNCcOhmvZsj0eQGLh/CXg4rONsS2REAof2W+JBg4QQwgHugG4MRV2MTuka64dM6uVRWEyUq1hDkmpcNT36mCW/V+auNP0ZUCXBktaOeUQDm0vfs4VeJp/YEBEwTitzdQOzOiBKp6Tvh85YOLOZXwZRpbb7aK8/gZ1lHY56g6hK6p/VyX0dkPvaAg2teAV/ZC2qlBt6gk06jvNb tbarron@tbarron
_EOF_

    echo "instance-id: $1; local-hostname: $1" > $META_DATA

    echo "$(date -R) Copying template image..."
    qemu-img create -f qcow2 -o preallocation=metadata $DISK 41G
    virt-resize --resize /dev/sda1=40G $IMAGE $DISK
    ##cp $IMAGE $DISK

    # Create CD-ROM ISO with cloud-init config
    echo "$(date -R) Generating ISO for cloud-init..."
    genisoimage -output $CI_ISO -volid cidata -joliet -r $USER_DATA $META_DATA &>> $1.log

    echo "$(date -R) Installing the domain and adjusting the configuration..."
    echo "[INFO] Installing with the following parameters:"
    echo "virt-install --import --name $1 --ram $MEM --vcpus $CPUS --disk
    $DISK,format=qcow2,bus=virtio --disk $CI_ISO,device=cdrom --network
    bridge=virbr0,model=virtio --os-type=linux --os-variant=ubuntu15.04 --noautoconsole"

    virt-install --import --name $1 --ram $MEM --vcpus $CPUS --disk \
    $DISK,format=qcow2,bus=virtio --disk $CI_ISO,device=cdrom --network \
    bridge=virbr0,model=virtio --os-type=linux --os-variant=ubuntu15.04 \
    --nographics --noautoconsole

    MAC=$(virsh dumpxml $1 | awk -F\' '/mac address/ {print $2}')
    while true
    do
        IP=$(grep -B1 $MAC /var/lib/libvirt/dnsmasq/$BRIDGE.status | head \
             -n 1 | awk '{print $2}' | sed -e s/\"//g -e s/,//)
        if [ "$IP" = "" ]
        then
            sleep 1
        else
            break
        fi
    done

    # Eject cdrom
    echo "$(date -R) Cleaning up cloud-init..."
    virsh change-media $1 hda --eject --config >> $1.log

    # Remove the unnecessary cloud init files
    rm $USER_DATA $CI_ISO

    echo "$(date -R) DONE. SSH to $1 using $IP, with  username 'centos'."

popd > /dev/null