Add extra_hosts for l2 config generation service (#5)

Part of [Create bridge channel in go-nitro](https://www.notion.so/Create-bridge-channel-in-go-nitro-22ce80a0d8ae4edb80020a8f250ea270)

Co-authored-by: Adw8 <adwaitgharpure@gmail.com>
Reviewed-on: cerc-io/fixturenet-optimism-stack#5
Co-authored-by: Prathamesh Musale <prathamesh.musale0@gmail.com>
Co-committed-by: Prathamesh Musale <prathamesh.musale0@gmail.com>

compose/docker-compose-fixturenet-optimism.yml

@@ -49,6 +49,8 @@ services:
       - l2_config:/l2-config
     entrypoint: "bash"
     command: "/generate-l2-config.sh"
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
 
   # Initializes and runs the L2 execution client  (outputs to volume l2_geth_data)
   op-geth:

config/fixturenet-optimism/generate-l2-config.sh

@@ -14,6 +14,13 @@ l1_deployment_file="/l1-deployment/$DEPLOYMENT_CONTEXT-deploy.json"
 l2_allocs_file="/l2-config/allocs-l2.json"
 genesis_outfile="/l2-config/genesis.json"
 rollup_outfile="/l2-config/rollup.json"
+jwt_file="/l2-config/l2-jwt.txt"
+
+# Create a JWT secret at shared path if not found
+if [ ! -f "$jwt_file" ]; then
+  openssl rand -hex 32 > $jwt_file
+  echo "Generated JWT secret at $jwt_file"
+fi
 
 # Check if genesis.json and rollup.json already exist
 if [ -f "$genesis_outfile" ] && [ -f "$rollup_outfile" ]; then

config/fixturenet-optimism/optimism-contracts/deploy-contracts.sh

@@ -177,6 +177,5 @@ echo "Copying deployment artifacts volume l1_deployment and deploy-config to vol
 cp /app/packages/contracts-bedrock/deployments/$DEPLOYMENT_CONTEXT-deploy.json /l1-deployment
 cp /app/packages/contracts-bedrock/deploy-config/$DEPLOYMENT_CONTEXT.json /l2-config
 cp allocs-l2.json /l2-config
-openssl rand -hex 32 > /l2-config/l2-jwt.txt
 
 echo "Deployment successful. Exiting"