Merge branch 'juerg/git-describe' into 'master'

git.py: Make `ref` human readable

See merge request BuildStream/buildstream!291

3 files changed, 74 insertions, 2 deletions

diff --git a/buildstream/plugins/sources/git.py b/buildstream/plugins/sources/git.py
index cc6d35cd0..77db9534a 100644
--- a/buildstream/plugins/sources/git.py
+++ b/buildstream/plugins/sources/git.py
@@ -43,6 +43,12 @@ git - stage files from a git repository
    # will be used to update the 'ref' when refreshing the pipeline.
    track: master
 
+   # Optionally specify the ref format used for tracking.
+   # The default is 'sha1' for the raw commit hash.
+   # If you specify 'git-describe', the commit hash will be prefixed
+   # with the closest tag.
+   ref-format: sha1
+
    # Specify the commit ref, this must be specified in order to
    # checkout sources and build, but can be automatically updated
    # if the 'track' attribute was specified.
@@ -205,7 +211,18 @@ class GitMirror(SourceFetcher):
             [self.source.host_git, 'rev-parse', tracking],
             fail="Unable to find commit for specified branch name '{}'".format(tracking),
             cwd=self.mirror)
-        return output.rstrip('\n')
+        ref = output.rstrip('\n')
+
+        if self.source.ref_format == 'git-describe':
+            # Prefix the ref with the closest tag, if available,
+            # to make the ref human readable
+            exit_code, output = self.source.check_output(
+                [self.source.host_git, 'describe', '--tags', '--abbrev=40', '--long', ref],
+                cwd=self.mirror)
+            if exit_code == 0:
+                ref = output.rstrip('\n')
+
+        return ref
 
     def stage(self, directory, track=None):
         fullpath = os.path.join(directory, self.path)
@@ -341,13 +358,18 @@ class GitSource(Source):
     def configure(self, node):
         ref = self.node_get_member(node, str, 'ref', None)
 
-        config_keys = ['url', 'track', 'ref', 'submodules', 'checkout-submodules']
+        config_keys = ['url', 'track', 'ref', 'submodules', 'checkout-submodules', 'ref-format']
         self.node_validate(node, config_keys + Source.COMMON_CONFIG_KEYS)
 
         self.original_url = self.node_get_member(node, str, 'url')
         self.mirror = GitMirror(self, '', self.original_url, ref, primary=True)
         self.tracking = self.node_get_member(node, str, 'track', None)
 
+        self.ref_format = self.node_get_member(node, str, 'ref-format', 'sha1')
+        if self.ref_format not in ['sha1', 'git-describe']:
+            provenance = self.node_provenance(node, member_name='ref-format')
+            raise SourceError("{}: Unexpected value for ref-format: {}".format(provenance, self.ref_format))
+
         # At this point we now know if the source has a ref and/or a track.
         # If it is missing both then we will be unable to track or build.
         if self.mirror.ref is None and self.tracking is None:
diff --git a/tests/sources/git.py b/tests/sources/git.py
index 8f6074fae..7ab32a6b5 100644
--- a/tests/sources/git.py
+++ b/tests/sources/git.py
@@ -476,3 +476,50 @@ def test_ref_not_in_track_warn_error(cli, tmpdir, datafiles):
     result = cli.run(project=project, args=['build', 'target.bst'])
     result.assert_main_error(ErrorDomain.STREAM, None)
     result.assert_task_error(ErrorDomain.PLUGIN, CoreWarnings.REF_NOT_IN_TRACK)
+
+
+@pytest.mark.skipif(HAVE_GIT is False, reason="git is not available")
+@pytest.mark.datafiles(os.path.join(DATA_DIR, 'template'))
+@pytest.mark.parametrize("ref_format", ['sha1', 'git-describe'])
+@pytest.mark.parametrize("tag,extra_commit", [(False, False), (True, False), (True, True)])
+def test_track_fetch(cli, tmpdir, datafiles, ref_format, tag, extra_commit):
+    project = os.path.join(datafiles.dirname, datafiles.basename)
+
+    # Create the repo from 'repofiles' subdir
+    repo = create_repo('git', str(tmpdir))
+    ref = repo.create(os.path.join(project, 'repofiles'))
+    if tag:
+        repo.add_tag('tag')
+    if extra_commit:
+        repo.add_commit()
+
+    # Write out our test target
+    element = {
+        'kind': 'import',
+        'sources': [
+            repo.source_config()
+        ]
+    }
+    element['sources'][0]['ref-format'] = ref_format
+    element_path = os.path.join(project, 'target.bst')
+    _yaml.dump(element, element_path)
+
+    # Track it
+    result = cli.run(project=project, args=['track', 'target.bst'])
+    result.assert_success()
+
+    element = _yaml.load(element_path)
+    new_ref = element['sources'][0]['ref']
+
+    if ref_format == 'git-describe' and tag:
+        # Check and strip prefix
+        prefix = 'tag-{}-g'.format(0 if not extra_commit else 1)
+        assert new_ref.startswith(prefix)
+        new_ref = new_ref[len(prefix):]
+
+    # 40 chars for SHA-1
+    assert len(new_ref) == 40
+
+    # Fetch it
+    result = cli.run(project=project, args=['fetch', 'target.bst'])
+    result.assert_success()
diff --git a/tests/testutils/repo/git.py b/tests/testutils/repo/git.py
index c598eb4d0..bc2dae691 100644
--- a/tests/testutils/repo/git.py
+++ b/tests/testutils/repo/git.py
@@ -42,6 +42,9 @@ class Git(Repo):
         self._run_git('commit', '-m', 'Initial commit')
         return self.latest_commit()
 
+    def add_tag(self, tag):
+        self._run_git('tag', tag)
+
     def add_commit(self):
         self._run_git('commit', '--allow-empty', '-m', 'Additional commit')
         return self.latest_commit()