Add endpoint for checking state of external processes

Long-running computations are handed off to external processes. This avoids
timeouts in the webserver, and also reduces chances of instability of the
webserver.

The results of these long-running computations are needed eventually, so this
commit provides a way to check for the state of the computation, and the
results if any.

1 files changed, 21 insertions, 0 deletions

diff --git a/gn3/api/async_commands.py b/gn3/api/async_commands.py
new file mode 100644
index 0000000..f8400c8
--- /dev/null
+++ b/gn3/api/async_commands.py
@@ -0,0 +1,21 @@
+"""Endpoints and functions concerning commands run in external processes."""
+import json
+
+import redis
+from flask import jsonify, Blueprint
+
+async_commands = Blueprint("async_commands", __name__)
+
+@async_commands.route("/state/<command_id>")
+def command_state(command_id):
+    with redis.Redis() as rconn:
+        state = rconn.hgetall(name=command_id)
+        if not state:
+            return jsonify(
+                status=404,
+                error="The command id provided does not exist.")
+        state = {
+            key.decode("utf-8"): val.decode("utf8")
+            for key,val in state.items()
+        }
+        return jsonify(state)