kvm-install-vm
A bash wrapper around virt-install to build virtual machines on a local KVM
hypervisor. You can run it as a normal user which will use qemu:///session to
connect locally to your KVM domains.
Tested on the latest Fedora.
Prerequisites
You need to have the KVM hypervisor installed, along with a few other packages:
- genisoimage or mkisofs
- virt-install
- libguestfs-tools-c
- qemu-img
- libvirt-client
To install the dependencies, run:
sudo dnf -y install genisoimage virt-install libguestfs-tools-c qemu-img libvirt-client wget
If you want to resolve guests by their hostnames, install the libvirt-nss package:
sudo dnf -y install libvirt-nss
Then, add libvirt and libvirt_guest to list of hosts databases in
/etc/nsswitch.conf. See here for more
information.
Usage
$ kvm-install-vm help
NAME
kvm-install-vm - Install virtual guests using cloud-init on a local KVM
hypervisor.
SYNOPSIS
kvm-install-vm COMMAND [OPTIONS]
DESCRIPTION
A bash wrapper around virt-install to build virtual machines on a local KVM
hypervisor. You can run it as a normal user which will use qemu:///session
to connect locally to your KVM domains.
COMMANDS
help - show this help or help for a subcommand
create - create a new guest domain
list - list all domains, running and stopped
remove - delete a guest domain
Creating Guest VMs
$ kvm-install-vm help create
NAME
kvm-install-vm create [OPTIONS] VMNAME
DESCRIPTION
Create a new guest domain.
OPTIONS
-a Autostart (default: false)
-b Bridge (default: virbr0)
-c Number of vCPUs (default: 1)
-d Disk Size (GB) (default: 10)
-D DNS Domain (default: example.local)
-f CPU Model / Feature (default: host)
-g Graphics type (default: spice)
-h Display help
-i Custom QCOW2 Image
-k SSH Public Key (default: $HOME/.ssh/id_rsa.pub)
-l Location of Images (default: $HOME/virt/images)
-L Location of VMs (default: $HOME/virt/vms)
-m Memory Size (MB) (default: 1024)
-M Mac address (default: auto-assigned)
-p Console port (default: auto)
-s Custom shell script
-t Linux Distribution (default: centos7)
-T Timezone (default: US/Eastern)
-u Custom user (defualt: $USER)
-v Be verbose
DISTRIBUTIONS
NAME DESCRIPTION LOGIN
amazon2 Amazon Linux 2 ec2-user
centos7 CentOS 7 centos
centos7-atomic CentOS 7 Atomic Host centos
centos6 CentOS 6 centos
debian9 Debian 9 (Stretch) debian
fedora27 Fedora 27 fedora
fedora27-atomic Fedora 27 Atomic Host fedora
fedora28 Fedora 28 fedora
fedora28-atomic Fedora 28 Atomic Host fedora
ubuntu1604 Ubuntu 16.04 LTS (Xenial Xerus) ubuntu
ubuntu1804 Ubuntu 18.04 LTS (Bionic Beaver) ubuntu
EXAMPLES
kvm-install-vm create foo
Create VM with the default parameters: CentOS 7, 1 vCPU, 1GB RAM, 10GB
disk capacity.
kvm-install-vm create -c 2 -m 2048 -d 20 foo
Create VM with custom parameters: 2 vCPUs, 2GB RAM, and 20GB disk
capacity.
kvm-install-vm create -t debian9 foo
Create a Debian 9 VM with the default parameters.
kvm-install-vm create -T UTC foo
Create a default VM with UTC timezone.
kvm-install-vm create -s ~/script.sh -g vnc -u bar foo
Create a VM with a custom script included in user-data, a graphical
console accessible over VNC, and a user named 'bar'.
Deleting a Guest Domain
$ kvm-install-vm help remove
NAME
kvm-install-vm remove [COMMANDS] VMNAME
DESCRIPTION
Destroys (stops) and undefines a guest domain. This also remove the
associated storage pool.
COMMANDS
help - show this help
EXAMPLE
kvm-install-vm remove foo
Remove (destroy and undefine) a guest domain. WARNING: This will
delete the guest domain and any changes made inside it!
Attaching a new disk
$ kvm-install-vm help attach-disk
NAME
kvm-install-vm attach-disk [OPTIONS] [COMMANDS] VMNAME
DESCRIPTION
Attaches a new disk to a guest domain.
COMMANDS
help - show this help
OPTIONS
-d SIZE Disk size (GB)
-f FORMAT Disk image format (default: qcow2)
-s IMAGE Source of disk device
-t TARGET Disk device target
EXAMPLE
kvm-install-vm attach-disk -d 10 -s example-5g.qcow2 -t vdb foo
Attach a 10GB disk device named example-5g.qcow2 to the foo guest
domain.
Setting Custom Defaults
Copy the .kivrc file to your $HOME directory to set custom defaults. This is
convenient if you find yourself repeatedly setting the same options on the
command line, like the distribution or the number of vCPUs.
Options are evaluated in the following order:
- Default options set in the script
- Custom options set in
.kivrc - Option flags set on the command line
Notes
-
This script will download a qcow2 cloud image from the respective
distribution's download site. See script for URLs. -
If using libvirt-nss, keep in mind that DHCP leases take some time to
expire, so if you create a VM, delete it, and recreate another VM with the
same name in a short period of time, there will be two DHCP leases for the
same host and its hostname will likely not resolve until the old lease
expires.
Testing
Tests are written using Bats. To
execute the tests, run ./test.sh in the root directory of the project.
Use Cases
If you don't need to use Docker or Vagrant, don't want to make changes to a
production machine, or just want to spin up one or more VMs locally to test
things like:
- high availability
- clustering
- package installs
- preparing for exams
- checking for system defaults
- anything else you would do with a VM
...then this wrapper could be useful for you.