Appendix A: BlockScout Explorer

To use Blockscout explorer follow this repo: https://github.com/poanetwork/blockscout-terraform

On the bootnode for blockscout, add/replace the following sections in the node.toml file. Restart poa-parity.service

[rpc]
apis = ["web3","eth","net", "parity", "traces"]
processing_threads = 2
server_threads = 2
cors=["all"]
[footprint]
tracing = "on"
pruning = "archive"
fat_db = "on"
[websockets]
#max_connections = 1000
apis = ["web3","eth","net","parity", "pubsub", "traces"]

Also, add the following section into the /etc/nginx/conf.d/default.conf file to enable websockets.

location /ws {
proxy_set_header Host localhost:8546;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header Content-Type application/json;
#add_header Access-Control-Allow-Origin "*";
#add_header Access-Control-Allow-Headers "Origin, X-Requested-With, Content-Type, Accept";
if ($request_method = 'OPTIONS') {
add_header Access-Control-Allow-Headers "Origin, X-Requested-With, Content-Type, Accept";
add_header Access-Control-Allow-Methods "GET, POST, OPTIONS";
add_header Access-Control-Allow-Origin "*";
add_header Access-Control-Max-Age 600;
add_header Content-Type 'text/plain charset=UTF-8';
add_header Content-Length 0;
return 204;
}
proxy_pass http://localhost:8546;
proxy_read_timeout 3600s;
proxy_send_timeout 3600s;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}

When configuring blockscout, you need to assign a public domain name to this node (make sure 443 port is open), e.g. https://blockscout-node-trace-ws.nowhere and use it for blockscout configuration, along with wss://blockscout-node-trace-ws.nowhere/ws for web-sockets.