fix: handle timeout on request dry-runs

price_feed_poller.py

@@ -9,6 +9,7 @@
 
 from config import load_config
 from contract import pf_contracts, pf_thresholds, wrb
+from threading import Timer
 from web3 import Web3, exceptions
 
 # Post a data request to the post_dr method of the WRB contract
@@ -164,9 +165,18 @@ def dry_run_request(bytecode):
   cmdline = "npx witnet-toolkit try-data-request --hex "
   cmdline += bytecode.hex()
   cmdline += " | tail -n 2 | head -n 1 | awk -F: '{ print $2 }' | sed 's/ //g' | tr -d \"│\""
+
   process = subprocess.Popen(cmdline, stdout=subprocess.PIPE, shell=True)
-  process.wait()
-  output, error = process.communicate()
+  timer = Timer(15, process.kill)
+  try:
+    timer.start()
+    process.wait()  
+    output, error = process.communicate()
+  finally:
+    timer.cancel()
+
+  if len(output) == 0:
+    raise Exception("Timeout while trying data request")
   if error is not None:
     raise Exception(error)
   return int(output)
@@ -266,9 +276,10 @@ def log_loop(
               # If thresholds is configured, evaluate actual price deviation  
               try:
                 next_price = dry_run_request(element['feed'].functions.bytecode().call())
-              except:
+              except Exception as ex:
                 # If dry run fails, assume 0 deviation as to, at least, guarantee the heartbeat periodicity is met
-                print("Cannot dry run request:", element['feed'].functions.bytecode().call().hex())
+                print("Cannot dry run request:", ex)
+                print(element['feed'].functions.bytecode().call().hex())
                 next_price = last_price
               deviation = round(100 * ((next_price - last_price) / last_price), 2)
               if abs(deviation) < thresholds[index] and elapsed_secs < max_secs_between_request_updates: