distrobox/docs/useful_tips.md

• Distrobox
  • Execute complex commands directly from distrobox-enter
  • Improve distrobox-enter performance
  • Slow creation on podman and image size getting bigger with distrobox-create
  • Container save and restore
  • Check used resources
  • Using podman inside a distrobox
  • Using docker inside a distrobox
  • Using init system inside a distrobox
  • Using distrobox as main cli
  • Build a Gentoo distrobox container
  • Build a Dedicated distrobox container

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Useful tips

Execute complex commands directly from distrobox-enter

Sometimes it is necessary to execure complex commands from a distrobox enter, like multiple concatenated commands using variables declared inside the container.

For example:

distrobox enter test -- bash -l -c '"echo \$HOME && whoami"'

Note the use of single quotes around double quotes, this is necessary so that quotes are preserved inside the arguments. Also note the dollar escaping needed so that $HOME is not evaluated at the time of the command launch, but directly inside the container.

Improve distrobox-enter performance

If you are experiencing a bit slow performance using podman you should enable the podman socket using

systemctl --user enable --now podman.socket

this will improve a lot podman's command performances.

Slow creation on podman and image size getting bigger with distrobox-create

For rootless podman 3.4.0 and upward, adding this to your ~/.config/containers/storage.conf file will improve container creation speed and fix issues with images getting bigger when using rootless containers.

[storage]
driver = "overlay"

[storage.options.overlay]
mount_program = "/usr/bin/fuse-overlayfs"

Container save and restore

To save, export and reuse an already configured container, you can leverage podman save or docker save and podman import or docker import to create snapshots of your environment.

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To save a container to an image:

with podman:

podman container commit -p distrobox_name image_name_you_choose
podman save image_name_you_choose:latest | gzip > image_name_you_choose.tar.gz

with docker:

docker container commit -p distrobox_name image_name_you_choose
docker save image_name_you_choose:latest | gzip > image_name_you_choose.tar.gz

This will create a tar.gz of the container of your choice at that exact moment.

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Now you can backup that archive or transfer it to another host, and to restore it just run

podman load < image_name_you_choose.tar.gz

or

docker load < image_name_you_choose.tar.gz

And create a new container based on that image:

distrobox-create --image image_name_you_choose:latest --name distrobox_name
distrobox-enter --name distrobox_name

And you're good to go, now you can reproduce your personal environment everywhere in simple (and scriptable) steps.

Check used resources

• You can always check how much space a distrobox is taking by using podman command:

podman system df -v or docker system df -v

Using podman inside a distrobox

If distrobox is using podman as the container engine, you can use podman socket to control host's podman from inside a distrobox, just use:

podman --remote

inside the distrobox to use it.

It may be necessary to enable the socket on your host system by using:

systemctl --user enable --now podman.socket

Using docker inside a distrobox

You can use docker to control host's podman from inside a distrobox, by default if distrobox is using docker as a container engine, it will mount the docker.sock into the container.

So in the container just install docker, add yourself to the docker group, and you should be good to go.

Using init system inside a distrobox

You can use an init system inside the container on supported images. Example of such images are:

• docker.io/almalinux/8-init
• registry.access.redhat.com/ubi7/ubi-init
• registry.access.redhat.com/ubi8/ubi-init

You can use such feature using:

distrobox create -i docker.io/almalinux/8-init --init --name test

Note however that in this mode, you'll not be able to access host's processes from within the container.

Example use:

~$ distrobox create -i docker.io/almalinux/8-init --init --name test

user@test:~$ sudo systemctl enable --now sshd

user@test:~$ sudo systemctl status sshd
    ● sshd.service - OpenSSH server daemon
       Loaded: loaded (/usr/lib/systemd/system/sshd.service; enabled; vendor preset: enabled)
       Active: active (running) since Fri 2022-01-28 22:54:50 CET; 17s ago
         Docs: man:sshd(8)
               man:sshd_config(5)
     Main PID: 291 (sshd)

Using distrobox as main cli

In case you want (like me) to use your container as the main CLI environment, it comes handy to use gnome-terminal profiles to create a dedicated setup for it:

Personally, I just bind Ctrl-Alt-T to the Distrobox profile and Super+Enter to the Host profile.

For other terminals, there are similar features (profiles) or you can set up a dedicated shortcut to launch a terminal directly in the distrobox