How to know if a machine is an Google Compute Engine instance

Question

Is there a way to know from a command line shell if I am currently on a Google Compute Engine machine or somewhere else (development machine)?

Answer 1

Per the metadata docs:

You can easily detect if your applications or scripts are running within a Compute Engine instance by using the metadata server. When you make a request to the server, any response from the metadata server will contain the Metadata-Flavor: Google header. You can look for this header to reliably detect if you are running in Compute Engine.

For example, the following curl request returns a Metadata-Flavor: Google header, indicating that the request is being made from within a Compute Engine instance.

me@my-inst:~$ curl metadata.google.internal -i
HTTP/1.1 200 OK
Metadata-Flavor: Google
Content-Type: application/text
Date: Thu, 10 Apr 2014 19:24:27 GMT
Server: Metadata Server for VM
Content-Length: 22
X-XSS-Protection: 1; mode=block
X-Frame-Options: SAMEORIGIN

0.1/
computeMetadata/

Answer 2

You can also do a DNS lookup for the Metadata server, instead of actually calling it.

For example, doing dig +short metadata.google.internal inside a Google Compute instance would output something like this:

[root@vm-1]# dig +short metadata.google.internal
169.254.169.254

If, however, you do the same command (dig +short metadata.google.internal) inside a standard server, outside of Google Cloud, you could get an empty response.

So to check, all you need to do (in bash for instance) is:

GMETADATA_ADDR=`dig +short metadata.google.internal`
if [[ "${GMETADATA_ADDR}" == "" ]]; then
    echo "I am NOT in a Google VM!"
else
    echo "I AM INSIDE a Google VM! Whoohoo!"
fi

Answer 3

Here is python implementation via socket.getaddrinfo

import socket


def is_gce_instance():
  """Check if it's GCE instance via DNS lookup to metadata server.
  """
  try:
    socket.getaddrinfo('metadata.google.internal', 80)
  except socket.gaierror:
    return False
  return True

Answer 4

You can also use the dmidecode utility to probe the virtual hardware if you don't want to make a network call:

my@myinst:~$ sudo dmidecode -s bios-vendor | grep Google
Google