cloud-image-builder

A command-line tool to easily build and initialize KVM cloud image.

• Author: Guochao Xie
• Date: 20-04-2022

Usage

1. Create a disk

$ ./create.sh [-h | bionic | focal | impish | jammy] [name] [size]

E.g. Create a jammy (Ubuntu 22.04) server image with name disk1.img and size 20G:

$ ./create.sh jammy disk1.img 20G

Note: the template image will be cached.

2. Set up password for the first time

./setup-password.sh [disk]

E.g.

./setup-password.sh disk1.img

It will prompt to input your initial password for the user ubuntu.

Then, it will boot up with 4 cores and 8G memory for the set up of password.

Important: You need to wait (for around 15 seconds after the prompt of log in) until the cloud-init runs and has the log like this:

cloudimg login: cloud-init[1003]: Cloud-init v. 22.1-14-g2e17a0d6-0ubuntu1~22.04.5 running.
cloud-init[1022]: Cloud-init v. 22.1-14-g2e17a0d6-0ubuntu1~22.04.5 running 'modules:final'.
ci-info: no authorized SSH keys fingerprints found for user ubuntu.
<14>Apr 20 10:39:11 cloud-init: ###########################################################
<14>Apr 20 10:39:11 cloud-init: -----BEGIN SSH HOST KEY FINGERPRINTS-----
<14>Apr 20 10:39:11 cloud-init: 1024 SHA256:oxqMWatvXmARpHtwH7awwearUz/TRmPEOFWHCujwWNI ro)
<14>Apr 20 10:39:11 cloud-init: 256 SHA256:8cTQ3pH+e91vidG4rlAEwRMFCATTTsiK1GCOjWfwd1Y roo)
<14>Apr 20 10:39:11 cloud-init: 256 SHA256:vLaOGEVv6Q6eZ+CYSNFPtU8fWNprGgmb/aCwKiBswxo roo)
<14>Apr 20 10:39:11 cloud-init: 3072 SHA256:wyZst2G4BzsHBTtsLB4WNEy92la5RbD7D87qVXJkBHg ro)
<14>Apr 20 10:39:11 cloud-init: -----END SSH HOST KEY FINGERPRINTS-----
<14>Apr 20 10:39:11 cloud-init: ###########################################################
-----BEGIN SSH HOST KEY KEYS-----
ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBDm0sKnOG28pEEFa+7g
ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDouZ55unYbrBgUqpBgm/VMmOuUpy2qRM9TVkcHc6m9e root@cloug
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABgQC6kk7Cp656dmIcH4pbHI2874ibrvbMv5aAJoeQ5IG786dpHIFJJPg
-----END SSH HOST KEY KEYS-----
cloud-init[1022]: Cloud-init v. 22.1-14-g2e17a0d6-0ubuntu1~22.04.5 finished at Wed, 20 Aprs

Now log in with user ubuntu and your password. You can now log in and configure your image like the SSH.

You can now run sudo poweroff to shut down the password setup process.

3. Use your image

Now, you've use your image disk. For example, to boot your disk1.img with 4 cores and 8G memory:

./boot.sh disk1.img

Possible Issues

By default we will download the kvm image to speed up. In case this image is incompatible, you can switch to the original image by removing -disk-kvm:

• download.sh: disk="${version}-server-cloudimg-amd64-disk-kvm.img" -> disk="${version}-server-cloudimg-amd64.img"
• create.sh: cp "img/${version}-server-cloudimg-amd64-disk-kvm.img" ${name} -> cp "img/${version}-server-cloudimg-amd64.img" ${name}

Motivation

I have a Mac M1 machine, but I need to hack Linux kernel. I can use the lab's server, but no x11 is available. Therefore, I create this repo for everyone in this situation...

Tried and failed many times with all disk data unaccessible...

Hope to save remote developers' lives.

Credits:

• NoCloud