distrobox/docs/useful_tips.md

• Distrobox
  • Execute complex commands directly from distrobox-enter
  • Create a distrobox with a custom HOME directory
  • Mount additional volumes in a distrobox
  • Use a different shell than the host
  • Duplicate an existing distrobox
  • Export to the host
  • Execute commands on the host
  • Enable SSH X-Forwarding when SSH-ing in a distrobox
  • Use distrobox to install different flatpaks from the host
  • Using podman inside a distrobox
  • Using docker inside a distrobox
  • Using init system inside a distrobox
  • Using distrobox as main cli
  • Improve distrobox-enter performance
  • Slow creation on podman and image size getting bigger with distrobox-create
  • Container save and restore
  • Check used resources
  • 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.

Create a distrobox with a custom HOME directory

distrobox-create supports the use of the --home flag, as specified in the usage HERE

Simply use:

distrobox-create --name test --image your-choosen-image:tag --home /your/custom/home

Mount additional volumes in a distrobox

distrobox-create supports the use of the --volume flag, as specified in the usage HERE

Simply use:

distrobox-create --name test --image your-choosen-image:tag --volume /your/custom/volume/path

Use a different shell than the host

By default distrobox will pick up the shell from the host and use it inside the container. If you want a different one you can use:

SHELL=/bin/zsh distrobox create -n test SHELL=/bin/zsh distrobox enter test

Duplicate an existing distrobox

It can be useful to just duplicate an already set up environment, to do this, distrobox-create supports the use of the --clone flag, as specified in the usage HERE

Simply use:

distrobox-create --name test --clone name-of-distrobox-to-clone

Export to the host

Distrobox supports exporting to the host either binaries, applications or systemd services. Head over the usage page to have an explanation and examples.

Execute commands on the host

You can check this little post about executing commands on the host.

Enable SSH X-Forwarding when SSH-ing in a distrobox

SSH X-forwarding by default will not work because the container hostname is different from the host's one. You can create a distrobox with will have the same hostname as the host by creating it with the following init-hook:

distrobox-create --name test --image your-choosen-image:tag --init-hooks '"$(uname -n)" > /etc/hostname'

This will ensure SSH X-Forwarding will work when SSH-ing inside the distrobox:

ssh -X myhost distrobox-enter test -- xclock

Use distrobox to install different flatpaks from the host

By default distrobox will integrate with host's flatpak directory if present: /var/lib/flatpak and obviously with the $HOME one.

If you want to have a separate system remote between host and container, you can create your distrobox with the followint init-hook:

distrobox-create --name test --image your-choosen-image:tag --init-hooks 'umount /var/lib/flatpak'

After that you'll be able to have separate flatpaks between host and distrobox. You can procede to export them using distrobox-export (for distrobox 1.2.14+)

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

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