4

I'm trying to provision a VM with cloud-init and the server live image. (I'm not using the cloud image, for infrastructural reasons I have to install from ISOs)

However, whenever I'm trying to combine autoinstall with e.g. write_files, the write_files part does not seem to succeed.

The following installs Ubuntu:

#cloud-config
autoinstall:
  version: 1
  identity:
    hostname: boxy-001
    password: "$1$k46kl1..."
    username: alice
  storage:
    layout:
      name: lvm
  ssh:
    install-server: true
    authorized-keys: 
      - "ecdsa-sha2-nistp256 AAAAE2...."


 


write_files:


    

  • content: |
    
cloud_init_has_run
    
path: /cloud_init_flag

But the file is not written at /cloud_init_flag.

Are modules missing? Is cloud-config incomplete on the Server live ISOs?

Edit the file is written, but it's written in the installation environment! Instead, I should likely use the autoinstall.user-data key to provide the user-data for the target system.

Tom
  • 213
  • Your write_files config works for me using the 20.04 live server installer. Is the rest of the autoinstall working? How are you confirming the file is missing? – Andrew Lowther Jun 08 '21 at 16:21
  • So, when using this user-data while installing Ubuntu 20.04 LTS with the live installer, the /cloud_init_flag is actually created? – Tom Jun 09 '21 at 07:51
  • I took your write_files section and added it to my user-data file. I started an install and opened a shell in the installer environment. The /cloud_init_flag was created with the configured content. My guesses: 1. your autoinstall file is not being used at all. 2. your autoinstall file is invalid and not getting parsed. 3. you expect the file to be on the installed system when it is just on the installation environment – Andrew Lowther Jun 10 '21 at 14:31
  • Aaah, that must be it. All cloud-init functions are executed in the install environment? Can I ask, how would I get cloud-init to run on the installed system in combination with autoinstall? – Tom Jun 21 '21 at 09:16

1 Answers1

7

how would I get cloud-init to run on the installed system in combination with autoinstall?

There is a user-data config key for the autoinstall file.

For example, if you want your write_files configuration to be used by cloud-init on the installed system then this snippet could be included as part of the autoinstall file.

#cloud-config
autoinstall:
  version: 1
  user-data:
    write_files:
    - content: |
        cloud_init_has_run
      path: /cloud_init_flag
...

How it works

  • During the install, subiquity will create configuration for cloud-init at /target/var/lib/cloud/seed/nocloud-net/user-data.
  • During the first boot of the installed system, cloud-init will use this config file to perform some of the install tasks. Notably, this is how the first user is created.
  • If a user-data section is included in the autoinstall file then subiquity will merge the user-data section into the generated /target/var/lib/cloud/seed/nocloud-net/user-data file.

Using the snippet above, the merged configuration resulted in this file content.

#cloud-config
growpart: {mode: 'off'}
locale: en_US.UTF-8
preserve_hostname: true
resize_rootfs: false
...
write_files:
- {content: 'cloud_init_has_run


', path: /cloud_init_flag}

During first boot, cloud-init did create the /cloud_init_flag file with the configured content.

Andrew Lowther
  • 7,286
  • Thank you. This would be a great addition to the concise documentation at https://ubuntu.com/server/docs/install/autoinstall-reference#user-data – Tom Jun 24 '21 at 07:31