[nodesocket]

Note, from Google Compute Engine use 8.8.8.8 as it should always be faster. I'm guessing the 8.8.8.8 service exists in every Google Cloud region. Even better use the default GCE autogenered DNS IP that they configure in /etc/resolv.conf to get instance name resolving magic.

[kentonv]

Usually best to use 169.254.169.254, which is the magic "cloud metadata address" that talks directly to the local hypervisor (I think?). That will recurse to public DNS as necessary. https://cloud.google.com/compute/docs/internal-dns

[jkaplowitz]

I agree that's usually best, but one exception is worth noting: if you want only publicly resolvable results, don't use 169.254.169.254. That address adds convenient predictable hostnames for your project's instances under the .internal TLD.

Also, no need to hardcode that address - DHCP will happily serve it up. It also has the hostname metadata.google.internal and the (disfavored for security reasons) bare short hostname metadata.