Merge branch 'tristan/bst-1/version-specific-config' into 'bst-1'

Support version specific configuration files

See merge request BuildStream/buildstream!1945

3 files changed, 48 insertions, 4 deletions

diff --git a/buildstream/_context.py b/buildstream/_context.py
index 8a7cec70c..f36bfd343 100644
--- a/buildstream/_context.py
+++ b/buildstream/_context.py
@@ -147,10 +147,15 @@ class Context():
         # a $XDG_CONFIG_HOME/buildstream.conf file
         #
         if not config:
-            default_config = os.path.join(os.environ['XDG_CONFIG_HOME'],
-                                          'buildstream.conf')
-            if os.path.exists(default_config):
-                config = default_config
+            #
+            # Support parallel installations of BuildStream by first
+            # trying buildstream1.conf and then falling back to buildstream.conf.
+            #
+            for config_filename in ("buildstream1.conf", "buildstream.conf"):
+                default_config = os.path.join(os.environ["XDG_CONFIG_HOME"], config_filename)
+                if os.path.exists(default_config):
+                    config = default_config
+                    break
 
         # Load default config
         #
diff --git a/doc/source/using_config.rst b/doc/source/using_config.rst
index 8b6cb58b0..f7469555b 100644
--- a/doc/source/using_config.rst
+++ b/doc/source/using_config.rst
@@ -22,6 +22,17 @@ invoking ``bst``, an attempt is made to load user specific configuration from
 ``$XDG_CONFIG_HOME/buildstream.conf``. On most Linux based systems, the location
 will be ``~/.config/buildstream.conf``
 
+.. note::
+
+   If you have have multiple major versions of BuildStream installed, you
+   can have separate configuration files in your ``${XDG_CONFIG_HOME}``.
+
+   You can do this by naming them according to the major versions of
+   BuildStream you have installed. BuildStream 1 will load it's configuration
+   from ``$XDG_CONFIG_HOME/buildstream1.conf`` and BuildStream 2 will load
+   it's configuration from ``$XDG_CONFIG_HOME/buildstream2.conf``, while
+   any version will fallback to ``$XDG_CONFIG_HOME/buildstream.conf``.
+
 
 Project specific value
 ----------------------
diff --git a/tests/context/context.py b/tests/context/context.py
index 35428105b..f76a4f07b 100644
--- a/tests/context/context.py
+++ b/tests/context/context.py
@@ -3,6 +3,7 @@ import pytest
 
 from buildstream._context import Context
 from buildstream._exceptions import LoadError, LoadErrorReason
+from buildstream import _yaml
 
 DATA_DIR = os.path.join(
     os.path.dirname(os.path.realpath(__file__)),
@@ -83,6 +84,33 @@ def test_context_load_user_config(context_fixture, datafiles):
     assert(context.logdir == os.path.join(cache_home, 'buildstream', 'logs'))
 
 
+@pytest.mark.datafiles(os.path.join(DATA_DIR))
+def test_context_priority(datafiles):
+    confdir = os.path.join(str(datafiles), "config")
+    os.makedirs(confdir)
+
+    # The fallback (usual) config file
+    bst_conf_path = os.path.join(confdir, "buildstream.conf")
+    bst_conf = {"sourcedir": "/sources"}
+    _yaml.dump(bst_conf, bst_conf_path)
+
+    # The version specific config file
+    bst_conf_path = os.path.join(confdir, "buildstream1.conf")
+    bst_conf = {"sourcedir": "/other_sources"}
+    _yaml.dump(bst_conf, bst_conf_path)
+
+    # Load the Context() object and assert that we've chosen
+    # the version specific one.
+    #
+    os.environ["XDG_CONFIG_HOME"] = confdir
+    context = Context()
+    context.load()
+
+    assert context.sourcedir == "/other_sources"
+
+    del os.environ["XDG_CONFIG_HOME"]
+
+
 #######################################
 #          Test failure modes         #
 #######################################