Package godnsbl lets you perform RBL (Real-time Blackhole List - https://en.wikipedia.org/wiki/DNSBL) lookups using Go.
The command-line tool in cmd demonstrates the use of goroutines to perform concurrent lookups.
To test:
git clone https://github.com/mrichman/godnsbl
cd godnsbl/cmd/godnsbl
go run main.go 127.0.0.2
The output will be a JSON-formatted list of results with the following fields:
[
...
{
"rbl": "b.barracudacentral.org",
"address": "127.0.0.2",
"listed": true,
"text": "http://www.barracudanetworks.com/reputation/?pr=1\u0026ip=127.0.0.2",
"error": false,
"error_type": null
}
...
]