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)?
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4 Answers
Answer recommended by Google Cloud Collective
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: Googleheader. 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: Googleheader, 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/
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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 
1 Comment
Crispy Holiday
While this solution works, the downside is that you cannot pass a custom timeout to
getaddrinfo, therefore it will hand for about 5 seconds before raising an exception when not running in GAE instanceYou 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 
1 Comment
famzah
This avoids the network call and is therefore more reliable and fast. Additionally, the
dmidecode method works for other cloud providers like Digital Ocean, for example.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 