Add a fallback RPC URL for fetching the eth gas price

Author: maximopalopoli

alerts/.env.devnet

@@ -4,6 +4,7 @@
 
 # # Variables for contract_alerts.sh
 # RPC_URL=<YOUR_RPC_URL>
+# RPC_URL_FALLBACK=<YOUR_FALLBACK_RPC_URL>
 # CONTRACT_ADDRESS=<YOUR_CONTRACT_ADDRESS>
 # NEW_BATCH_TOPIC=<YOUR_NEW_BATCH_TOPIC>
 # VERIFIED_BATCH_TOPIC=<YOUR_VERIFIED_BATCH_TOPIC>
@@ -17,6 +18,7 @@
 
 # # Variables for balance_alerts.sh
 # RPC_URL=<YOUR_RPC_URL>
+# RPC_URL_FALLBACK=<YOUR_FALLBACK_RPC_URL>
 # PAYMENT_CONTRACT_ADDRESS=<YOUR_PAYMENT_CONTRACT_ADDRESS>
 # BALANCE_THRESHOLD=<YOUR_BALANCE_THRESHOLD_IN_ETH>
 # WALLET_ADDRESS=<YOUR_WALLET_ADDRESS>

alerts/.env.example

@@ -17,6 +17,7 @@ EXPRESSION=<GREP_EXPRESSION>
 
 # Variables for balance_alerts.sh
 RPC_URL=<YOUR_RPC_URL>
+RPC_URL_FALLBACK=<YOUR_FALLBACK_RPC_URL>
 PAYMENT_CONTRACT_ADDRESS=<YOUR_PAYMENT_CONTRACT_ADDRESS>
 BALANCE_THRESHOLD=<YOUR_BALANCE_THRESHOLD_IN_ETH>
 WALLET_NAME=<YOUR_WALLET_NAME> # Example: "Task sender"
@@ -37,6 +38,7 @@ LOGS_BLOCK_RANGE=<LOGS_BLOCK_RANGE>
 CONTRACT_ADDRESS=<YOUR_CONTRACT_ADDRESS>
 AGGREGATED_PROOF_VERIFIED_TOPIC=0xfe3e9e971000ab9c80c7e06aba2933aae5419d0e44693e3046913e9e58053f62
 RPC_URL=<YOUR_RPC_URL>
+RPC_URL_FALLBACK=<YOUR_FALLBACK_RPC_URL>
 LOGS_BLOCK_RANGE=7500
 SLEEP_TIME=3600
 PAGER_DUTY_KEY=<YOUR_PAGER_DUTY_KEY>

alerts/periodic_sender.sh

@@ -14,6 +14,11 @@ fi
 function fetch_gas_price() {
     # TODO: We should have a second RPC_URL for fetching gas price to avoid being rate limited
     gas_price=$(cast gas-price --rpc-url $RPC_URL)
+    if [[ -z "$gas_price" || "$gas_price" == "0" ]]; then
+        echo "Primary RPC_URL failed to fetch gas price, trying fallback..."
+        gas_price=$(cast gas-price --rpc-url $RPC_URL_FALLBACK)
+    fi
+
     echo $gas_price
 }
 
@@ -27,6 +32,15 @@ while true; do
     echo "Starting pass #$tic"
 
     current_gas_price=$(fetch_gas_price)
+    if [[ -z "$current_gas_price" || "$current_gas_price" == "0" ]]; then
+        echo "Failed to fetch current gas price from both RPC URLs, skipping this pass."
+
+        tic=$((tic + 1))
+
+        echo "Sleeping $sleep_time seconds (($((sleep_time / 60)) minutes))"
+        sleep "$sleep_time"
+        continue
+    fi
     echo "Current gas price: $current_gas_price wei"
 
     # In case current tic and gas price meet the criteria, send a proof and reset tic counter