Monday, May 9, 2016

Booting ubuntu 16.04 cloud images on Arm64

For testing kvm/qemu, prebaked images cloud images are nice. However, there is a few steps to get started. First we need a recent Qemu (2.5 is good enough). An efi firmware is needed, and cloud-utils, for customizing our VM.
sudo apt install -y qemu qemu-utils cloud-utils
Cloud images are plain - there is no user setup, no default user/pw combo, so to log in to the image, we need to customize the image on first boot. The defacto tool for this is cloud-init. The simplest method for using cloud-init is passing a block media with a settings file - of course for real cloud deployment, you would use one of fancy network based initialization protocols cloud-init supports. Enter the following to a file, say cloud.txt:

  - name: you
      - ssh-rsa AAAAB3Nz....
    sudo: ['ALL=(ALL) NOPASSWD:ALL']
    groups: sudo
    shell: /bin/bash
This minimal config will just set you a user with ssh key. A more complex setup can install packages, write files and run arbitrary commands on first boot. In professional setups, you would most likely end up using cloud-init only to start Ansible or another configuration management tool.
cloud-localds cloud.img cloud.txt
qemu-system-aarch64 -smp 2 -m 1024 -M virt -bios QEMU_EFI.fd -nographic \
       -device virtio-blk-device,drive=image \
       -drive if=none,id=image,file=xenial-server-cloudimg-arm64-uefi1.img \
       -device virtio-blk-device,drive=cloud \
       -drive if=none,id=cloud,file=cloud.img \
       -netdev user,id=user0 -device virtio-net-device,netdev=user0 -redir tcp:2222::22 \
       -enable-kvm -cpu host 
If you are on an X86 host and want to use qemu to run an aarch64 image, replace the last line with "-cpu cortex-a57". Now, since the example uses user networking with tcp port redirect, you can ssh into the VM:
ssh -p 2222 you@localhost
Welcome to Ubuntu 16.04 LTS (GNU/Linux 4.4.0-22-generic aarch64)

Wednesday, February 17, 2016

Ancient Linux swag

Since I've now been using Linux for 20 years, I've dug up some artifacts from the early journey.

  1. First the book, from late 1995. This from before Tux, so the penguin in the cover is just a co-incidence. The book came with a slackware 3.0 CD, which was my entrance to Linux. Today, almost all of the book is outdated - slackware and lilo install? printing with lpr? mtools and dosemu? ftp, telnet with SLIP dialup? Manually configuring XFree86 and fvwm? How I miss those times!* The only parts of the book are still valid are: shell and vi guides. I didn't read latter, and instead imported my favorite editor from dos FTE.
  2. Fast forward some years, into my first programming job. Ready to advertise the Linux revolution, I bought the mug on right. Nobody else would have a Tux mug, so nobody would accidentally take my mug from the office dishwasher. That only worked for my first work place (a huge and nationally hated IT consultant house). The next workplace, a mobile gaming startup (in 2001, I was there before it was trendy!) - and there was already plenty of Linux mugs when I joined...
  3. While today it may be hard to imagine, those days using Microsoft office tools was mandatory. That leads to the third memorabilia in the picture. Wordperfect for Linux existed for a brief while, and in the box (can you imagine, software came in physical boxes?) came a Tux plush.

* Wait no, I don't miss those times at all