Improved uWSGI & GUnicorn App Names (#171)

* Check if uwsgi API available and use to detect environment

* Better names for gunicorn too

Author: pglombardo

instana/meter.py

@@ -153,6 +153,7 @@ def reset(self):
         self.last_collect = None
         self.last_metrics = None
         self.snapshot_countdown = 0
+        self.cached_snapshot = None
         self.thread = None
 
         self.thread = threading.Thread(target=self.collect_and_report)
@@ -240,25 +241,77 @@ def handle_agent_tasks(self, task):
 
         self.agent.task_response(task["messageId"], payload)
 
+    def get_proc_cmdline(self):
+        name = None
+        if os.path.isfile("/proc/self/cmdline"):
+            with open("/proc/self/cmdline") as cmd:
+                name = cmd.read()
+        return name
+
+    def get_application_name(self):
+        # One environment variable to rule them all
+        if "INSTANA_SERVICE_NAME" in os.environ:
+            return os.environ["INSTANA_SERVICE_NAME"]
+
+        # Now best effort in naming this process.  No nice package.json like in Node.js
+        # so we do best effort detection here.
+
+        basename = os.path.basename(sys.argv[0])
+        if basename == "gunicorn":
+            # gunicorn renames their processes to pretty things - we use those by default
+            # gunicorn: master [djface.wsgi]
+            # gunicorn: worker [djface.wsgi]
+            app_name = self.get_proc_cmdline()
+
+            if app_name is None:
+                app_name = basename
+        elif "FLASK_APP" in os.environ:
+            app_name = os.environ["FLASK_APP"]
+        elif "DJANGO_SETTINGS_MODULE" in os.environ:
+            app_name = os.environ["DJANGO_SETTINGS_MODULE"].split('.')[0]
+        elif basename == '':
+            if sys.stdout.isatty():
+                app_name = "Interactive Console"
+            else:
+                # No arguments.  Take executable as app_name
+                app_name = os.path.basename(sys.executable)
+        else:
+            # Last chance.  app_name for "python main.py" would be "main.py" here.
+            app_name = basename
+
+        # We should have a good app_name by this point.
+        # Last conditional, if uwsgi, then wrap the name
+        # with the uwsgi process type
+        if basename == "uwsgi":
+            # We have an app name by this point.  Now if running under
+            # uwsgi, augment the appname
+            try:
+                import uwsgi
+
+                if app_name == "uwsgi":
+                    app_name = ""
+                else:
+                    app_name = " [%s]" % app_name
+
+                if os.getpid() == uwsgi.masterpid():
+                    uwsgi_type = "uWSGI master%s"
+                else:
+                    uwsgi_type = "uWSGI worker%s"
+
+                app_name = uwsgi_type % app_name
+            except ImportError:
+                pass
+
+        logger.warn("App name is: %s", app_name)
+        return app_name
+
     def collect_snapshot(self):
         """  Collects snapshot related information to this process and environment """
         try:
             if self.cached_snapshot is not None:
                 return self.cached_snapshot
 
-            if "INSTANA_SERVICE_NAME" in os.environ:
-                appname = os.environ["INSTANA_SERVICE_NAME"]
-            elif "FLASK_APP" in os.environ:
-                appname = os.environ["FLASK_APP"]
-            elif "DJANGO_SETTINGS_MODULE" in os.environ:
-                appname = os.environ["DJANGO_SETTINGS_MODULE"].split('.')[0]
-            elif os.path.basename(sys.argv[0]) == '' and sys.stdout.isatty():
-                appname = "Interactive Console"
-            else:
-                if os.path.basename(sys.argv[0]) == '':
-                    appname = os.path.basename(sys.executable)
-                else:
-                    appname = os.path.basename(sys.argv[0])
+            appname = self.get_application_name()
 
             s = Snapshot(name=appname, version=platform.version(),
                          f=platform.python_implementation(),