Fedora 19: mount cirros qcow2 image with guestfs-tools

small tips

When evaluating openstack RDO by using cirros images, I would like to change root user’s credentials from default credentials “cubswin:)” to other letters before booting instances.Because I could not enter colon “:” via VNC in my environment for some reasons.

Here’s how to mount cirros qcow2 image and edit /etc/shadow.

I changed credentials to hello.

dump credentials for shadow file

# echo "hello"| openssl passwd -1 -stdin $1$/xfGm6Qk$zSUqaHU5nycXbK/Za.D1v0

install libguestfs-tools and mount qcow2 image.

# yum install libguestfs-tools - mount qcow2 image # mkdir mnt # guestmount --rw -a cirros-0.3.1-x86_64-disk.img -i mnt # cd mnt/ # cd etc/ - before editing shadow # cat shadow root:!$1$LJwQnqlv$DK6oKqcTq9Rf2ClC.kMa3/:10933:0:99999:7::: bin:*:10933:0:99999:7::: daemon:*:10933:0:99999:7::: adm:*:10933:0:99999:7::: lp:*:10933:0:99999:7::: sync:*:10933:0:99999:7::: shutdown:*:10933:0:99999:7::: halt:*:10933:0:99999:7::: uucp:*:10933:0:99999:7::: operator:*:10933:0:99999:7::: ftp:*:10933:0:99999:7::: nobody:*:10933:0:99999:7::: cirros:$1$LJwQnqlv$DK6oKqcTq9Rf2ClC.kMa3/:10933:0:99999:7::: # cp shadow shadow.org - after editing shadow file # cat shadow root:$1$/xfGm6Qk$zSUqaHU5nycXbK/Za.D1v0:10933:0:99999:7::: bin:*:10933:0:99999:7::: daemon:*:10933:0:99999:7::: adm:*:10933:0:99999:7::: lp:*:10933:0:99999:7::: sync:*:10933:0:99999:7::: shutdown:*:10933:0:99999:7::: halt:*:10933:0:99999:7::: uucp:*:10933:0:99999:7::: operator:*:10933:0:99999:7::: ftp:*:10933:0:99999:7::: nobody:*:10933:0:99999:7::: cirros:$1$/xfGm6Qk$zSUqaHU5nycXbK/Za.D1v0:10933:0:99999:7::: # cd ../.. - unmount # guestunmount mnt/