clients/besu: implement retry mechanism to get enode (#595)

* clients/besu: implement retry mechanism to get enode

* exit if enode URL not available after 5 seconds

Co-authored-by: Mario Vega <marioevz@gmail.com>

Author: fab-10

clients/besu/enode.sh

@@ -10,7 +10,12 @@
 set -e
 
 data='{"jsonrpc":"2.0","method":"admin_nodeInfo","params":[],"id":1}'
-TARGET_RESPONSE=$(curl -s -X POST  -H "Content-Type: application/json"  --data $data "localhost:8545" )
+while [[ "$TARGET_RESPONSE" != *enode* ]]
+do
+    TARGET_RESPONSE=$(curl -s -X POST  -H "Content-Type: application/json"  --data $data "localhost:8545" )
+    ((c++)) && ((c==50)) && break
+    sleep 0.1
+done
 
 TARGET_ENODE=$(echo ${TARGET_RESPONSE}| jq -r '.result.enode')
 echo "$TARGET_ENODE"