Printing out message when a peer connects

Lets say I’ve set up a host like so:

ctx := context.Background()
opt := []libp2p.Option {
	libp2p.ListenAddrStrings("/ip4/" + c.Port),
	// Load private key to create p2p ID
	// Use the noise encryption protocol
	libp2p.Security(noise.ID, noise.New),
	// support TLS connections
	libp2p.Security(libp2ptls.ID, libp2ptls.New),
	// Attempt to open ports using uPNP for NATed hosts.

host, err := libp2p.New(ctx, opt...)
if err != nil {
	return Client {}, fmt.Errorf("Failed to open P2P Host: %s", err)

How would i go about printing a message in console when a different peer connects?