Move the versionstring code out of app.homeserver into util

synapse/util/versionstring.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import subprocess
+import os
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def get_version_string(name, module):
+    try:
+        null = open(os.devnull, 'w')
+        cwd = os.path.dirname(os.path.abspath(module.__file__))
+        try:
+            git_branch = subprocess.check_output(
+                ['git', 'rev-parse', '--abbrev-ref', 'HEAD'],
+                stderr=null,
+                cwd=cwd,
+            ).strip()
+            git_branch = "b=" + git_branch
+        except subprocess.CalledProcessError:
+            git_branch = ""
+
+        try:
+            git_tag = subprocess.check_output(
+                ['git', 'describe', '--exact-match'],
+                stderr=null,
+                cwd=cwd,
+            ).strip()
+            git_tag = "t=" + git_tag
+        except subprocess.CalledProcessError:
+            git_tag = ""
+
+        try:
+            git_commit = subprocess.check_output(
+                ['git', 'rev-parse', '--short', 'HEAD'],
+                stderr=null,
+                cwd=cwd,
+            ).strip()
+        except subprocess.CalledProcessError:
+            git_commit = ""
+
+        try:
+            dirty_string = "-this_is_a_dirty_checkout"
+            is_dirty = subprocess.check_output(
+                ['git', 'describe', '--dirty=' + dirty_string],
+                stderr=null,
+                cwd=cwd,
+            ).strip().endswith(dirty_string)
+
+            git_dirty = "dirty" if is_dirty else ""
+        except subprocess.CalledProcessError:
+            git_dirty = ""
+
+        if git_branch or git_tag or git_commit or git_dirty:
+            git_version = ",".join(
+                s for s in
+                (git_branch, git_tag, git_commit, git_dirty,)
+                if s
+            )
+
+            return (
+                "%s/%s (%s)" % (
+                    name, module.__version__, git_version,
+                )
+            ).encode("ascii")
+    except Exception as e:
+        logger.info("Failed to check for git repository: %s", e)
+
+    return ("%s/%s" % (name, module.__version__,)).encode("ascii")