+ MBS Offline local builds

+ ========================

+ 

+ MBS can build modules locally in offline mode. This means that MBS will only use repositories

+ which are enabled locally in `/etc/yum.repos.d` as dependencies, and will not query any external

+ infrastructure (except the RPM repositories identified in /etc/yum.repos.d) to build a module.

+ 

+ This document describes how to build modules in this way.

+ 

+ 

+ Definition of module to build

+ =============================

+ 

+ The module to build offline is defined by a regular modulemd yaml file. This file does not have

+ to live in a git repository. The following are things to keep in mind in regards to offline local

+ builds:

+ 

+ - The buildrequired platform stream must be the one provided by the local system. You can see

+   the platform stream your system provides by checking the PLATFORM_ID in the ``/etc/os-release``

+   file.

+ - To build components (RPMs) defined by a spec file and sources from some local path, you need

+   to define `repository: file:///home/user/path/to/component` for each component. For more

+   information, refer to the modulemd specification. If you do not specify the ``repository``,

+   MBS will get this component from the configured remote dist-git as it would normally do.

+ 

+ 

+ Definition of local components (RPMs) to build

+ ==============================================

+ 

+ To build a component (RPM) defined locally in some directory, you need to specify the path to it

+ in the `repository` section of the component in the modulemd definition of the module as

+ described earlier in this document.

+ 

+ Important facts about this directory are:

+ 

+ - The directory with the component must be a git repository.

+ - All changes you want to include in the local module build must be committed.

+ - The directory must contain all the sources referred to by the spec file.

+ 

+ In case you want to test some change in some Fedora package by building it in a module locally,

+ you can get such directory by these commands::

+ 

+     $ fedpkg clone some-rpm-package

+     $ cd some-rpm-package

+     $ fedpkg prep

+     $ vi some-fedora-package.spec

+     ... do some local changes ...

+     $ git commit -a -m 'testing offline local builds'

+ 

+ 

+ Building module locally in offline mode

+ =======================================

+ 

+ Note: In the future, it might be possible that fedpkg provides a better user-experience than

+ the way described here. This is using the mbs-manager directly, which is not intended to be

+ used by the end-user, but it is so far the only way to perform offline local builds.

+ 

+ A module can be built locally using following command::

+ 

+     $ mbs-manager build_module_locally --file=/home/user/module.yaml --offline -r /etc/yum.repos.d/fedora.repo -r /etc/yum.repos.d/fedora-updates.repo

+ 

+ Here is a description of the arguments that were used:

+ 

+ - ``--file`` - Defines the full-path to the modulemd file that defines the module to build.

+ - ``--offline`` - Enables the offline local module builds mode.

+ - ``-r`` - The full path to the `.repo` files with repositories defining the platform module.

+   These repositories contain the non-modular RPMs which form the basic buildroot for the module.

+ 

+ When ``mbs-manager build_module_locally`` is executed, it will do the following:

+ 

+ - It examines all the repositories enabled locally to find out all the available modules defined

+   in these repositories.

+ - Using the list of available modules, it resolves the dependencies between them and chooses

+   the combination which will be built locally.

+ - In the case that Module Stream Expansion generates multiple contexts (possible builds),

+   the user needs to choose the one they want to build using the `-s` or `--set-stream` argument.

+ - The Mock configuration is generated from ``/etc/module-build-service/mock.cfg`` template

+   and ``/etc/module-build-service/yum.conf`` template.

+ - The local repositories with modules and the repositories defined by ``-r`` argument are added

+   to the buildroot using the ``yum.conf`` template.

+ - Mock is used to build each component.

+ - The built modules are stored in ``~/modulebuild/builds``.