ceremonyclient/go-libp2p/examples/testutils/net.go
2023-08-20 23:07:43 -05:00

38 lines
693 B
Go

package testutils
import (
"fmt"
"net"
"testing"
)
// FindFreePort attempts to find an unused tcp port
func FindFreePort(t *testing.T, host string, maxAttempts int) (int, error) {
t.Helper()
if host == "" {
host = "localhost"
}
for i := 0; i < maxAttempts; i++ {
addr, err := net.ResolveTCPAddr("tcp", net.JoinHostPort(host, "0"))
if err != nil {
t.Logf("unable to resolve tcp addr: %v", err)
continue
}
l, err := net.ListenTCP("tcp", addr)
if err != nil {
l.Close()
t.Logf("unable to listen on addr %q: %v", addr, err)
continue
}
port := l.Addr().(*net.TCPAddr).Port
l.Close()
return port, nil
}
return 0, fmt.Errorf("no free port found")
}