Programmatically get host's ip from within Docker container with Python

Question

I'm aware that you can get a host's ip programatically with Python doing something like:

from socket import gethostname, gethostbyname

ip = gethostbyname(gethostname())
print(ip)

but, as expected, when running the code mentioned above from a container (just ftr, with user namespaces enabled) the output is 172.17.0.2.

How can I programmatically get the host's ip from within the container?

Note: I'm working in a Linux environment.

A container can't normally see the host's IP addresses (plural); this is doubly true if you're running inside a VM-based Docker environment like Docker Desktop. Using the host ip in docker-compose suggests an approach based on finding an appropriate IP address on the host and injecting it into the container as an environment variable; does that work for you? — David Maze
– David Maze, Commented Jan 5, 2023 at 17:09
@DavidMaze I think the option of passing the IP address as an environment variable is the only one left. Thanks! — albertoperdomo2
– albertoperdomo2, Commented Jan 6, 2023 at 7:57

NiRR · Accepted Answer · 2023-01-05 13:12:35Z

2

This works on my mac

ip = gethostbyname('docker.for.mac.localhost')

answered Jan 5, 2023 at 13:12

NiRR

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1 Comment

sorry, I have updated the questions. I need it for Linux systems. Btw, I think nowadays is host.docker.internal.