Fail gracefully when virtuoso is not accessible

* gn3/api/metadata.py: import RemoteDisconnected.
(jsonify_dataset_metadata): Wrap get_dataset_metadata in try block.

1 files changed, 12 insertions, 6 deletions

diff --git a/gn3/api/metadata.py b/gn3/api/metadata.py
index 4fe9e67..680d51b 100644
--- a/gn3/api/metadata.py
+++ b/gn3/api/metadata.py
@@ -1,4 +1,5 @@
 """API for fetching metadata using an API"""
+from http.client import RemoteDisconnected
 from flask import Blueprint
 from flask import jsonify
 from flask import current_app
@@ -14,9 +15,14 @@ metadata = Blueprint("metadata", __name__)
 @metadata.route("/dataset/<accession_id>", methods=["GET"])
 def jsonify_dataset_metadata(accession_id):
     """Fetch a dataset's metadata given it's ACCESSION_ID"""
-    return jsonify(get_dataset_metadata(
-        SPARQLWrapper(current_app
-                      .config
-                      .get("SPARQL_ENDPOINT")),
-        accession_id
-    ).data)
+    try:
+        return jsonify(
+            get_dataset_metadata(
+                SPARQLWrapper(current_app.config.get("SPARQL_ENDPOINT")),
+                accession_id,
+            ).data
+        )
+    # The virtuoso server is misconfigured or it isn't running at all
+    except RemoteDisconnected:
+        return jsonify({})
+