Use WORKER_VERSION_ID env var in helper methods

Requires backend!876

Closes #9 (closed)

arkindex_worker/worker.py

@@ -30,7 +30,8 @@ class BaseWorker(object):
             self.work_dir = os.path.join(xdg_data_home, "arkindex")
             os.makedirs(self.work_dir, exist_ok=True)
 
-        if not os.environ.get("WORKER_VERSION_ID"):
+        self.worker_version_id = os.environ.get("WORKER_VERSION_ID")
+        if not self.worker_version_id:
             raise Exception(
                 "Missing WORKER_VERSION_ID environment variable to start the Worker"
             )
@@ -197,7 +198,7 @@ class ElementsWorker(BaseWorker):
                 "corpus": element.corpus.id,
                 "polygon": polygon,
                 "parent": element.id,
-                "worker_version": os.environ.get("WORKER_VERSION_ID"),
+                "worker_version": self.worker_version_id,
             },
         )
         self.report.add_element(element.id, type)