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


With app-portage/layman 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.).

USE flags for app-portage/layman Tool to manage Gentoo overlays

bazaar Support dev-vcs/bzr based overlays local
cvs Support dev-vcs/cvs based overlays local
darcs Support dev-vcs/darcs based overlays local
g-sorcery Support app-portage/g-sorcery based overlays local
git Support dev-vcs/git based overlays local
gpg Support app-crypt/gnupg signed overlays lists and manifests local
mercurial Support dev-vcs/mercurial based overlays local
sqlite Add support for sqlite - embedded sql database global
squashfs Support mounting squashfs image overlays locally read-only local
subversion Support dev-vcs/subversion based overlays local
sync-plugin-portage Install the sys-apps/portage sync module local
test Workaround to pull in packages needed to run with FEATURES=test. Portage-2.1.2 handles this internally, so don't set it in make.conf/package.use anymore global


Next install the Layman package:

root #emerge --ask app-portage/layman


There are two methods how to integrate layman into portage. Recent sys-apps/portage versions support both methods at the same time, so there is no need to configure portage (except configurations mentioned in this section).

This article has some todo items:
  • Please specify version number for very old (Portage) versions

make.conf method (older method)

This is an older method, still widely used. Very old portage versions support only this method.

Modifying layman.cfg might be unnecessary, depending on layman version.

Configure layman to use make.conf method in /etc/layman/layman.cfg. Older layman installations will have this already set:

FILE /etc/layman/layman.cfg
# Repository config types used by layman
# (repos.conf, make.conf)
conf_type : make.conf

Insert a reference to Layman in /etc/portage/make.conf

root #echo "source /var/lib/layman/make.conf" >> /etc/portage/make.conf

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

FILE /etc/portage/make.confEnsuring that layman's PORTDIR_OVERLAY is not overwritten

repos.conf method (default method for app-portage/layman-2.3.0 or later )

This method uses a new portage plugins system. Layman will create its configuration file in /etc/portage/repos.conf/ directory. There is no need for PORTDIR_OVERLAY changes in /etc/portage/make.conf.

Configure layman to use repos.conf method in /etc/layman/layman.cfg. New installations of layman will probably have this already set correctly:

FILE /etc/layman/layman.cfg
# Repository config types used by layman
# (repos.conf, make.conf)
conf_type : repos.conf

Create /etc/portage/repos.conf/ directory, if it does not exist yet:

If you have app-portage/layman-2.3.0 or later installed, you can force a rebuild of layman's repos.conf files:

root #layman-updater -R


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:

root #layman -L

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

root #layman -a <name>

To add an unofficial overlay:

root #layman -o <url of repository xml file> -f -a <name>

To remove an overlay from the local list:

root #layman -d <name>

To update a specific overlay:

root #layman -s <name>

To update all overlays:

root #layman -S

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:

root #layman-mounter -l

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

root #layman-mounter -L

To mount the mountable overlays, type:

root #layman-mounter -m <name>

To unmount the overlays, type:

root #layman-mounter -u <name>

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 /var/lib/layman/installed.xml 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 PORTDIR_OVERLAY variable defined in /var/lib/layman/make.conf.

As the file /var/lib/layman/make.conf is automatically generated by layman based on the settings in /var/lib/layman/installed.xml, it is strongly recommended that only /var/lib/layman/installed.xml 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 /var/lib/layman/make.conf is sourced.

FILE /var/lib/layman/make.confExample layman overlays setting
${PORTDIR_OVERLAY}" #the variable defined in /etc/portage/make.conf is now expanded
                    #when /var/lib/layman/make.conf is sourced in /etc/portage/make.conf

However, this can be also "fooled" by defining the PORTDIR_OVERLAY in /etc/portage/make.conf after /var/lib/layman/make.conf has been sourced.

FILE /etc/portage/make.confCustom overlay setting
source /var/lib/layman/make.conf #this sources the PORTDIR_OVERLAY variable defined by layman.
                                 #however, the variable expanded by layman was empty
PORTDIR_OVERLAY="/home/user/overlay ${PORTDIR} ${PORTDIR_OVERLAY}" #now the layman defined overlays take precedence,
                                                                   #but the user defined overlay still has the lowest priority

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, find their repository XML files and add them using the -o option.

Example: repositories.xml in brother-overlay

In case the overlay does not provide a repository XML file, create it manually in the /etc/layman/overlays folder.

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

FILE /etc/layman/overlays/larry.xmlLarry the cow's ngix overlay
<?xml version="1.0" ?>

<repositories version="1.0">
	<repo priority="50" quality="experimental" status="unofficial">
		<description>nginx server for the barn computer from Larry the cow.</description>
		<source type="git"></source>

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 /etc/layman/overlays 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:

root #layman-overlay-maker

and go through its prompts until completion.

When finished run:

root #layman-updater -R

Followed by

root #layman -a <name>

where <name> is the name of the overlay you just created.

See also

External resources