each nwaku service uses its index to retrieve a private key for keystore

docker-compose.yml

@@ -77,7 +77,6 @@ services:
     entrypoint: sh
     environment:
       - RPC_URL=${RPC_URL:-http://foundry:8545}
-      - PRIVATE_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80
       - RLN_CONTRACT_ADDRESS=0x9fE46736679d2D9a65F0992F2272dE9f3c7fa6e0
       - RLN_CREDENTIAL_PATH=/keystore.json
       - RLN_CREDENTIAL_PASSWORD=passw123
@@ -85,6 +84,7 @@ services:
       - '/opt/run_nwaku.sh'
     volumes:
       - ./run_nwaku.sh:/opt/run_nwaku.sh:Z
+      - privatekeys-volume:/shared
     depends_on:
       contract-repo-deployer:
         condition: service_completed_successfully

getPrivateKeys.sh

@@ -10,6 +10,6 @@ json_content=$(cat anvil-config.txt)
 # Extract private_keys array values using jq
 private_keys=$(echo "$json_content" | jq -r '.private_keys[]')
 
-# Write private keys to a new file for easier access
+# Write private keys to a new file for easier indexing
 echo "Writing private keys to file"
 echo "$private_keys" > /shared/private-keys.txt

run_nwaku.sh

@@ -33,12 +33,34 @@ else
     fi
 fi
 
+#Function to get the index of the container and use it to retrieve a private key to generate the keystore
+get_private_key(){
+  IP=$(ip a | grep "inet " | grep -Fv 127.0.0.1 | sed 's/.*inet \([^/]*\).*/\1/')
+
+  # get the service name you specified in the docker-compose.yml 
+  # by a reverse DNS lookup on the IP
+  SERVICE=`dig -x $IP +short | cut -d'_' -f2`
+
+  # the number of replicas is equal to the A records 
+  # associated with the service name
+  COUNT=`dig $SERVICE +short | wc -l`
+
+  # extract the replica number from the same PTR entry
+  INDEX=`dig -x $IP +short | sed 's/.*_\([0-9]*\)\..*/\1/'`
+
+  key=$(sed -n "${INDEX}p" /shared/private-keys.txt)
+  echo $key
+}
+
 if test -f .$RLN_CREDENTIAL_PATH; then
   echo "$RLN_CREDENTIAL_PATH already exists. Use it instead of creating a new one."
 else
+  private_key="$(get_private_key)"
+  echo "Private key: $private_key"
+
   /usr/bin/wakunode generateRlnKeystore \
     --rln-relay-eth-client-address="$RPC_URL" \
-    --rln-relay-eth-private-key=$PRIVATE_KEY  \
+    --rln-relay-eth-private-key=$private_key  \
     --rln-relay-eth-contract-address=$RLN_CONTRACT_ADDRESS \
     --rln-relay-cred-path=$RLN_CREDENTIAL_PATH \
     --rln-relay-cred-password=$RLN_CREDENTIAL_PASSWORD \