Automatically set LIBS_FROM_GIT based on required projects
If a project shows up in zuul's required-projects list, add it
to LIBS_FROM_GIT automatically. This way, when a user specifies
that a job requires a zuul-project, it gets used in testing, but
otherwise, it doesn't (pypi is used instead).
Also add information about what happens behind the scenes for both
LIBS_FROM_GIT and plugin dependencies.
This moves the check performed in check_libs_from_git to
a helper function which is installed for most kinds of
installations. This means that if someone sets LIBS_FROM_GIT to
"foobar", devstack won't error anymore, as nothing is going to
try to install foobar, therefore the check won't run on that.
However, as we move to automated generation of the local config,
that error is not likely to happen. This check was originally
added due to an error in the upper-constraints file (where a
constraint name did not match a package name). This location of
the check would still catch that type of error.
Change-Id: Ifcf3ad008cf42d3d4762cfb3b6c31c93cfeb40db
diff --git a/roles/write-devstack-local-conf/README.rst b/roles/write-devstack-local-conf/README.rst
index 73f9f0d..bfce9c9 100644
--- a/roles/write-devstack-local-conf/README.rst
+++ b/roles/write-devstack-local-conf/README.rst
@@ -20,6 +20,14 @@
bash shell variables, and will be ordered so that variables used by
later entries appear first.
+ As a special case, the variable ``LIBS_FROM_GIT`` will be
+ constructed automatically from the projects which appear in the
+ ``required-projects`` list defined by the job. To instruct
+ devstack to install a library from source rather than pypi, simply
+ add that library to the job's ``required-projects`` list. To
+ override the automatically-generated value, set ``LIBS_FROM_GIT``
+ in ``devstack_localrc`` to the desired value.
+
.. zuul:rolevar:: devstack_local_conf
:type: dict
@@ -75,3 +83,7 @@
A dictionary mapping a plugin name to a git repo location. If the
location is a non-empty string, then an ``enable_plugin`` line will
be emmitted for the plugin name.
+
+ If a plugin declares a dependency on another plugin (via
+ ``plugin_requires`` in the plugin's settings file), this role will
+ automatically emit ``enable_plugin`` lines in the correct order.