KVM on Ubuntu 20.04 using (Ubuntu) cloud images

kvm-on-ubuntu.md

Running virtual machines on KVM and Ubuntu 20.04 using (Ubuntu) cloud images

1. Check: egrep -c '(vmx|svm)' /proc/cpuinfo
2. Check: sudo kvm-ok
3. Install:

sudo apt update
sudo apt install qemu-kvm libvirt-daemon-system libvirt-clients bridge-utils virt-manager cloud-image-utils

4. Add yourself to the libvirt and kvm groups:

sudo adduser $USER libvirt
sudo adduser $USER kvm

5. Check: virsh list --all
6. Check: sudo systemctl status libvirtd
7. Export needed variables:

export MAC_ADDR=$(printf '52:54:00:%02x:%02x:%02x' $((RANDOM%256)) $((RANDOM%256)) $((RANDOM%256)))
export INTERFACE=eth001
export IP_ADDR=192.168.122.101
export VM_NAME=vm01
export UBUNTU_RELEASE=focal
export VM_IMAGE=$UBUNTU_RELEASE-server-cloudimg-amd64-disk-kvm.img

8. Download the Ubuntu 20.04 cloud image:

wget https://cloud-images.ubuntu.com/$UBUNTU_RELEASE/current/$UBUNTU_RELEASE-server-cloudimg-amd64-disk-kvm.img

9. Create a disk image:

qemu-img create -F qcow2 -b ./$VM_IMAGE -f qcow2 ./$VM_NAME.qcow2 10G

10. Create cloud-init files:

cat >network-config <<EOF                                                             
ethernets:    
    $INTERFACE:
        addresses:
        - $IP_ADDR/24
        dhcp4: false
        gateway4: 192.168.122.1
        match:
            macaddress: $MAC_ADDR
        nameservers:
            addresses:
            - 1.1.1.1
            - 8.8.8.8
        set-name: $INTERFACE
version: 2
EOF

cat >user-data <<EOF
#cloud-config
hostname: $VM_NAME
manage_etc_hosts: true
users:
  - name: vmadm
    sudo: ALL=(ALL) NOPASSWD:ALL
    groups: users, admin
    home: /home/vmadm
    shell: /bin/bash
    lock_passwd: false
ssh_pwauth: true
disable_root: false
chpasswd:
  list: |
    vmadm:vmadm
  expire: false
EOF

touch meta-data

11. Attach cloud-init to the image:

cloud-localds -v --network-config=network-config ./$VM_NAME-seed.qcow2 user-data meta-data

12. Create the VM:

virt-install --connect qemu:///system \
  --virt-type kvm \
  --name $VM_NAME \
  --ram 1024 \ 
  --vcpus=2 \
  --os-type linux \
  --os-variant ubuntu20.04 \
  --disk path=$VM_NAME.qcow2,device=disk \
  --disk path=$VM_NAME-seed.qcow2,device=disk \
  --import \
  --network network=default,model=virtio,mac=$MAC_ADDR \
  --noautoconsole

13. SSH to the VM or attach the console, use vmadm as username and password:

virsh console $VM_NAME
ssh vmadm@${IP_ADDRESS}

14. Destroy the VM

virsh destroy $VM_NAME
virsh undefine $VM_NAME