Toolbox is a tool that offers a familiar package based environment for developing and debugging software that runs fully unprivileged using Podman.

The toolbox container is a fully mutable container; when you see yum install ansible for example, that's something you can do inside your toolbox container, without affecting the base operating system.

This is particularly useful on OSTree based operating systems like CoreOS and Silverblue. The intention of these systems is to discourage installation of software on the host, and instead install software as (or in) containers.

However, this tool doesn't require using an OSTree based system — it works equally well if you're running e.g. existing Fedora Workstation or Server, and that's a useful way to incrementally adopt containerization.

The toolbox environment is based on an OCI image. On Fedora this is the fedora-toolbox image. This image is used to create a toolbox container that seamlessly integrates with the rest of the operating system.

Usage

Create your toolbox container:

[user@hostname ~]$ toolbox create
Created container: fedora-toolbox-30
Enter with: toolbox enter
[user@hostname ~]$

This will create a container called fedora-toolbox-<version-id>.

Enter the toolbox:

[user@hostname ~]$ toolbox enter
⬢[user@toolbox ~]$

Distro support

By default, Toolbox creates the container using an OCI image called <ID>-toolbox:<VERSION-ID>, where <ID> and <VERSION-ID> are taken from the host's /usr/lib/os-release. For example, the default image on a Fedora 30 host would be fedora-toolbox:30.

This default can be overridden by the --image option in toolbox create, but operating system distributors should provide an adequately configured default image to ensure a smooth user experience.

Image requirements

Toolbox customizes newly created containers in a certain way. This requires certain tools and paths to be present and have certain characteristics inside the OCI image.

Tools:

• getent(1)
• id(1)
• ln(1)
• mkdir(1): for hosts where /home is a symbolic link to /var/home
• passwd(1)
• readlink(1)
• rm(1)
• rmdir(1): for hosts where /home is a symbolic link to /var/home
• sleep(1)
• test(1)
• touch(1)
• unlink(1)
• useradd(8)

Paths:

• /etc/host.conf: optional, if present not a bind mount
• /etc/hosts: optional, if present not a bind mount
• /etc/krb5.conf.d: directory, not a bind mount
• /etc/localtime: optional, if present not a bind mount
• /etc/resolv.conf: optional, if present not a bind mount
• /etc/timezone: optional, if present not a bind mount

The image should have sudo(8) enabled for users belonging to either the sudo or wheel groups, and the group itself should exist. File an issue if you really need support for a different group. However, it's preferable to keep this list as short as possible.

Since Toolbox only works with OCI images that fulfill certain requirements, it will refuse images that aren't tagged with com.github.containers.toolbox="true" and com.github.debarshiray.toolbox="true" labels. These labels are meant to be used by the maintainer of the image to indicate that they have read this document and tested that the image works with Toolbox. You can use the following snippet in a Dockerfile for this:

LABEL com.github.containers.toolbox="true" \
      com.github.debarshiray.toolbox="true"