[apache#4695] Fix (python-client): Fix gradlew :clients:client-python…

…:build failed if the package does not contain .git directory (apache#4705)

### What changes were proposed in this pull request?

Fix gradlew :clients:client-python:build failed if the package does not
contain .git directory

### Why are the changes needed?

Fix: apache#4695 

### Does this PR introduce _any_ user-facing change?

NO

### How was this patch tested?

Manually test

Co-authored-by: Yuhui <hui@datastrato.com>

clients/client-python/gravitino/constants/root.py

@@ -21,4 +21,5 @@
 
 MODULE_NAME = "gravitino"
 PROJECT_HOME = Path(__file__).parent.parent.parent
+PROJECT_ROOT = PROJECT_HOME.parent.parent
 GRAVITINO_DIR = PROJECT_HOME / MODULE_NAME

clients/client-python/scripts/generate_version.py

@@ -17,17 +17,35 @@
 under the License.
 """
 
+# coding=utf-8
+
 import re
 import configparser
-import subprocess
 from datetime import datetime
+from gravitino.constants.root import PROJECT_ROOT
 
 from gravitino.constants.version import Version, VERSION_INI, SETUP_FILE
 from gravitino.exceptions.base import GravitinoRuntimeException
 
 VERSION_PATTERN = r"version\s*=\s*['\"]([^'\"]+)['\"]"
 
 
+def get_git_commit_id():
+    try:
+        commit_id = ""
+        git_path = f"{PROJECT_ROOT}/.git/"
+        with open(git_path + "HEAD", "r", encoding="utf-8") as file:
+            ref = file.readline().strip()
+
+        if ref.startswith("ref:"):
+            ref_path = ref.split(" ")[1]
+            with open(git_path + ref_path, "r", encoding="utf-8") as file:
+                commit_id = file.readline().strip()
+        return commit_id
+    except (FileNotFoundError, IOError):
+        return ""
+
+
 def main():
     with open(SETUP_FILE, "r", encoding="utf-8") as f:
         setup_content = f.read()
@@ -37,9 +55,7 @@ def main():
         else:
             raise GravitinoRuntimeException("Can't find valid version info in setup.py")
 
-    git_commit = (
-        subprocess.check_output(["git", "rev-parse", "HEAD"]).decode("ascii").strip()
-    )
+    git_commit = get_git_commit_id()
 
     compile_date = datetime.now().strftime("%d/%m/%Y %H:%M:%S")