Installing and using cloud containers on ChromeOS instead of the default supplied by Google

This is a work in progress that explains how to install cloud containers with minimal ChromeOS integration.

Ideally it would be possible to launch a custom vm using vmc. I'd even be happy to have the default termina kernel and initrd with custom rw rootfs.

Since that's not possible without putting the whole device into developer mode, this is the best alternative I have come up with.

Alternate cloud images can be used and this cloud-cfg.yaml can be used as a possible starting point. Found Here The cloud should be relatively painless to get working.

See the Warning below with regard to alternate container names.

Remove and reinstall the linux development environment to ensure you have a clean start

1. In the Settings application (Advanced -> Developers -> Linux development environment) Click the "Remove Linux development environment" button if present and wait for it to complete.
2. Restart the computer
3. In the Settings application (Advanced -> Developers) Next to "Linux development environment," select Turn On.
4. Wait till this completes

while this is time consuming, it should only need to be done once and will save a lot of greif later

Remove the default penguin image completely before installing something else

1. Open crosh with the shortcut Ctrl+Alt+T and execute the following commands
2. crosh> vsh termina
3. (termina) chronos@localhost ~ $ lxc list

+---------+---------+-----------------------+-------------------------------------------+-----------+-----------+
|  NAME   |  STATE  |         IPV4          |                   IPV6                    |   TYPE    | SNAPSHOTS |
+---------+---------+-----------------------+-------------------------------------------+-----------+-----------+
| penguin | RUNNING | 100.115.92.199 (eth0) | 2601:646:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx (eth0) | CONTAINER | 0         |
+---------+---------+-----------------------+-------------------------------------------+-----------+-----------+

4. (termina) chronos@localhost ~ $ lxc delete penguin
5. (termina) chronos@localhost ~ $ lxc list

+------+-------+------+------+------+-----------+
| NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+------+-------+------+------+------+-----------+

This is enough to ensure a relatively clean start, but will lose some storage (around 250M) for the initial image that was downloaded.

This file contains the commands that will completely cleanup the storage used in use by lxd for the removed container lxc-commands.md

Launch the debian based linux container in the VM

Google only provides packages for specific versions of Debian, so set up essential services and software using cloud-init

1. Save a copy of cloud-cfg.yaml curl https://raw.githubusercontent.com/ptorre/crostini-lxc-cloud-containers/main/cloud-cfg.yaml > /tmp/cloud-cfg.yaml

2. Edit cloud-cfg.yaml

   • change 'default_user.name` to what you would like to use
   • change the - loginctl enable-linger ptorre line at the to use the chosen user name
   • you can also add to the list of packages that will be installed during instance creation.
   • make the editied file available in the termina vm, so you can pass it as input to the lxc launch ... command
     • If you ran the above curl command you can use sed to edit the file in place (there is no real editor installed in termina): sed -i.bak -e 's/ptorre/whatever/' /tmp/cloud-cfg.yaml

3. Run lxc launch images:debian/12/cloud penguin < .../cloud-cfg.yaml at the termina command line

   • you must use the name 'penguin' so that the terminal application will detect the container
   • You can wait for cloud-init completion with the command lxc exec penguin -- cloud-init status --long --wait

You can attempt debugging from a shell in termina by connecting to containers directly: Open a crosh termina (Ctrl+Alt+T) type vsh termina then lxc exec <container-name> -- bash

After this point you should be able to create more containers in termina manually with lxc launch ...

When creating subsequent containers you can leave the container-name blank and one will be generated. Creating multiple containers from the same image will be much faster than different images. For example:

• lxc launch -e images:rockylinux/9/cloud < .../cloud-cfg.yaml creating an ephemeral container
• lxc launch -e images:rockylinux/9/cloud < .../cloud-cfg.yaml after images is downloaded subsequent containers should start almost immediately
• lxc launch -e images:rockylinux/9/cloud < .../cloud-cfg.yaml
• lxc launch images:ubuntu/jammy/cloud < /tmp/cloud-cfg.yaml will need to download the jammy image
• etc..
• check the cloud-init status for each container using the command
  • lxc exec <container-name> -- cloud-init status
• etc..

Warning

Major issues with dissapearing containers and leaking storage to unreferenceable images/files

Termina seems to sometimes lose containers and images from the lxd database

Only creating containers called penguin may prevent this

It is also wise to manually delete images when you are finished installing with them See the notes in lxc-commands.md

Crostini Reset LXD DB on launch set to Enabled (chrome://flags/#crostini-reset-lxd-db) is a bad idea. Because this also means all containers not named penguin are LOST whenever the termina vm is restarted. You should consider any container not named penguin to be ephemeral.** (You may even prefer to add the -e or --ephemeral option to the lxc launch ... command so that they are marked as such.
The last time I checked the storage tney are using when they are lost, becomes innaccesable but is not deleted.

There are other known issues: https://bugs.chromium.org/p/chromium/issues/detail?id=1146390#c6

The archlinux wiki has more information on how the linux development environment is set up and other issues people have encountered. https://wiki.archlinux.org/title/Chrome_OS_devices/Crostini