Change from pkg_resources to importlib metadata (#329)

* Change from pkg_resources to importlib metadata

CHANGELOG.md

@@ -12,6 +12,7 @@
 - Fixes:
   - Fix unexpected 'No active span' IllegalStateError (#311)
   - **Tentative**: Set upper bound <=5.9.5 for psutil package due to test failure. (#326)
+  - Remove `DeprecationWarning` from `pkg_resources` by replace it with `importlib_metadata` (#329)
 
 ### 1.0.1
 

skywalking/plugins/__init__.py

@@ -20,7 +20,22 @@
 import re
 import traceback
 
-import pkg_resources
+import sys
+
+if sys.version_info < (3, 8):
+    import pkg_resources
+    PackageNotFoundException = pkg_resources.DistributionNotFound
+
+    def get_pkg_version(pkg_name):
+        return pkg_resources.get_distribution(pkg_name).version
+
+else:
+    import importlib.metadata
+    PackageNotFoundException = importlib.metadata.PackageNotFoundError
+
+    def get_pkg_version(pkg_name):
+        return importlib.metadata.version(pkg_name)
+
 from packaging import version
 
 import skywalking
@@ -78,8 +93,8 @@ def pkg_version_check(plugin):
     rules = plugin.version_rule.get('rules')
 
     try:
-        current_pkg_version = pkg_resources.get_distribution(pkg_name).version
-    except pkg_resources.DistributionNotFound:
+        current_pkg_version = get_pkg_version(pkg_name)
+    except PackageNotFoundException:
         # when failed to get the version, we consider it as supported.
         return supported
 

tools/grpc_code_gen.py

@@ -18,11 +18,18 @@
 import os
 import re
 
-import pkg_resources
 from grpc_tools import protoc
 from packaging import version
+import sys
+
+if sys.version_info < (3, 8):
+    import pkg_resources
+    grpc_tools_version = pkg_resources.get_distribution('grpcio-tools').version
+
+else:
+    import importlib.metadata
+    grpc_tools_version = importlib.metadata.version('grpcio-tools')
 
-grpc_tools_version = pkg_resources.get_distribution('grpcio-tools').version
 dest_dir = 'skywalking/protocol'
 src_dir = 'protocol'