Updating qcow2 image using virt-customize in Linux (RHEL 8/ Fedora / CentOS)

Updating qcow2 image using virt-customize in Linux (RHEL 8)

Please use this link to install virt-customize in linux (RHEL 8)

Setting the root password for qcow2 image,

$ virt-customize -a overcloud-full.qcow2 --root-password password:test

[   0.0] Examining the guest ...
libvirt: XML-RPC error : Cannot recv data: Connection reset by peer
virt-customize: error: libguestfs error: could not connect to libvirt (URI
= qemu:///session): Cannot recv data: Connection reset by peer [code=38
int1=104]

If reporting bugs, run virt-customize with debugging enabled and include
the complete output:

  virt-customize -v -x [...]
  

Checking the status of libvirtd daemon,

$ systemctl status libvirtd

● libvirtd.service - Virtualization daemon
   Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
   Active: inactive (dead)
 	Docs: man:libvirtd(8)
       	https://libvirt.org
       	

Starting libvirtd and enabling default,

$ sudo systemctl enable libvirtd
$ sudo systemctl start libvirtd

Now set the qcow2 image root password,

$ virt-customize -a overcloud-full.qcow2 --root-password password:test

[   0.0] Examining the guest ...
libvirt: XML-RPC error : Cannot recv data: Connection reset by peer
virt-customize: error: libguestfs error: could not connect to libvirt (URI
= qemu:///session): Cannot recv data: Connection reset by peer [code=38
int1=104]

If reporting bugs, run virt-customize with debugging enabled and include
the complete output:

  virt-customize -v -x [...]
  

need to export LIBGUESTFS_BACKEND and $LIBVIRT_DEFAULT_URI if not set

$  export LIBGUESTFS_BACKEND=direct
$ echo $LIBVIRT_DEFAULT_URI

$ export LIBVIRT_DEFAULT_URI=qemu:///system
$ echo $LIBVIRT_DEFAULT_URI
qemu:///system

trying again,

$ virt-customize -a overcloud-full.qcow2 --root-password password:test
[   0.0] Examining the guest ...
[  12.5] Setting a random seed
[  12.5] Setting the machine ID in /etc/machine-id
[  12.5] Setting passwords
[  15.2] Finishing off

Installing a package in qcow2 image

virt-customize -a $1.qcow2 --run-command 'yum install -y wget'

Removing a installed package in qcow2 image

 virt-customize -a $1.qcow2 --run-command 'yum remove wget'
 

Updating qcow2 image using guestfish

Updating qcow2 image using guestfish,

$ guestfish -a  overcloud-full.qcow2

Welcome to guestfish, the guest filesystem shell for
editing virtual machine filesystems and disk images.

Type: ‘help’ for help on commands
  	‘man’ to read the manual
  	‘quit’ to quit the shell

><fs> run
><fs> mount /dev/sda /
><fs> vi /etc/default/grub
------------------
save the changes
><fs> exit