Layman

Layman is Gentoo's primary overlay management tool, offering centralized repository management for end users.

Features
With users can manage their overlays in a simple, centralized manner. The Layman application provides an overview of available remote overlay repositories and allows the user to select one or more for the system. Once selected, the user can update the repositories (similar to emerge --sync), add local overlays, and more.

USE flags
Installing Layman is a breeze. First check the USE flags that the Layman package supports; most of the USE flags trigger which kinds of remote repository types layman supports (such as git repositories, cvs repositories, etc.).

Emerge
Next install the Layman package:

Configuration
Insert a reference to Layman in

Adding the  command to the  (performed in the command above) will ensure that Portage, when asked, will check the content of the various overlays managed by Layman in the  file. In effect, it will update the  variable with directories Layman uses. If a special directory has been previously defined for  in, make sure its value is not overwritten with the value Layman provides.

Basic invocations
The Layman man page (see External resources) provides a full overview of the available functions within Layman. However, for most users, the following commands suffice for overlay management activities.

To fetch and display a list of all the overlays available through official references:

To add an overlay in the list generated by the local list:

To remove an overlay from the local list:

To update a specific overlay:

To update all overlays:

Mountable overlays with layman-mounter
Since the release of layman-2.2.0, support for squashfs overlay types has been included. layman will interact with squashfs overlays by mounting them as read-only on the filesystem. On the initial install of the squashfs overlay, it will be mounted as read-only. However, after a reboot the overlay will no longer be mounted and the ebuilds in that overlay will not be accessible by the system.

In order to assist users in handling these mountable overlays, a utility was added that goes by the name of layman-mounter.

To find all overlays that are currently mounted, type:

To find all overlays that are installed by layman that can be mounted, type:

To mount the mountable overlays, type:

To unmount the overlays, type:

Setting overlay priorities with Layman
As each overlay is assigned a unique priority, layman provides a simple way of defining priorities for overlays it manages. For more information about overlay priorities see the overlay article.

The file contains some information about the overlays, among which is the priority attribute in the repo tag. The number there determines only the priority relative to the other overlay entries, 50 is the default value. layman then analyses this file and sets the order of the overlay entries in the  variable defined in.

As the file is automatically generated by layman based on the settings in, it is strongly recommended that only  is used to set the priorities.

To add a personal overlay, and to ensure that the overlay has a higher priority, add the overlay before is sourced.

However, this can be also "fooled" by defining the  in  after  has been sourced.

This "trick" is merely an opportunity offered by shell variable expansion.

Adding custom overlays
To add overlays which are not listed when layman -L is ran add XML files into the folder.

For example, if Larry the cow were to create an overlay:

NEW: With the addition of layman-2.2.0 a new utility was added to assist users in this process that goes by the name of layman-overlay-maker. As long as the overlay information has been properly added via the prompts,layman-overlay-maker will create a XML defined overlay and save into or the specified in the layman configuration file for overlay_defs.

layman-overlay-maker can become a useful tool in assisting users who would like to submit a patch to have their overlays added to the official repositories.xml file.

To use the utility simply invoke it by name:

and go through its prompts until completion.

When finished run:

External resources

 * The Layman man page locally ( man layman ) or online at Sourceforge.net