Print version on startup

The version is determined from either the contents of _version.py
(expected to be present in release tarballs) or the output of
`git describe --always`.

ankisyncd/__init__.py

@@ -3,3 +3,31 @@ import sys
 
 sys.path.insert(0, "/usr/share/anki")
 sys.path.insert(0, os.path.join(os.path.dirname(os.path.dirname(__file__)), "anki-bundled"))
+
+_homepage = "https://github.com/tsudoko/anki-sync-server"
+_unknown_version = "[unknown version]"
+
+
+def _get_version():
+    try:
+        from ankisyncd._version import version
+
+        return version
+    except ImportError:
+        pass
+
+    import subprocess
+
+    try:
+        return (
+            subprocess.run(
+                ["git", "describe", "--always"],
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+            )
+            .stdout.strip()
+            .decode()
+            or _unknown_version
+        )
+    except (FileNotFoundError, subprocess.CalledProcessError):
+        return _unknown_version