How can I get the local IP address in macOS to use in a script?

Question

I need to figure out the local IP address of Github runner, which uses macOS 11. I need this for my integration tests.

I tried:

LOCAL_IP=ifconfig | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}'
SERVER_URL="http://${LOCAL_IP}:5000"

However, this gave me just: http://:5000

Which is the correct command for this?

Related https://apple.stackexchange.com/questions/60160/how-can-i-find-my-ip-address-not-my-companys-router-but-my-local-machines, but the answers there are not easily useable in a script. — nohillside, Jun 26 '21 at 12:04
I know that there are many related questions, but I do not find any answer for a solution based on shell script. — DarkMath, Jun 26 '21 at 12:20
Are these scripts running on the same machine as the server? If not is the server on a fixed machine? — mmmmmm, Jun 26 '21 at 13:10
I have a mono repository containing a python backend (flask) and a Flutter app. I've written end-to-end tests and now I want them to run in the pipeline. Therefore, I wrote a Github action file that starts the backend and after that the flutter integration tests. For this I need the IP of the backend, which runs locally on the MacOS Github runner. — DarkMath, Jun 26 '21 at 13:13
I have two questions 1)Do you really need to write this as a script? For a one-off discovery it would be far easier to just look in the Network control Panel. 2) is this inside the same Mac? If so, then it's always 127.0.0.1. — Tetsujin, Jun 26 '21 at 17:42
Then you need to look at the documentation of the app that provides the VM (e.g. virtualbox, docker ...) andsee how it sets up its network — mmmmmm, Jun 27 '21 at 09:35
I didn't find anything in the documentation: https://docs.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners#about-self-hosted-runners and here https://github.com/actions/virtual-environments — DarkMath, Jun 27 '21 at 14:07

score 11 · Answer 1 · answered Jun 26 '21 at 11:52

11

The local IP address can be obtained with the following command:

ipconfig getifaddr en0

or en1, depending on your Mac and your connection.

answered Jun 26 '21 at 11:52

benwiggy

35,635

Does not work for me: /Users/runner/work/_temp/f51fbf9d-2251-420a-ad21-c16451b2e107.sh: line 4: getifaddr: command not found – DarkMath Jun 26 '21 at 12:14
1

@DarkMath The command is ipconfig getifaddr en0. – nohillside Jun 26 '21 at 12:15
@benwiggy Yes I tried. But the Github runner does not know the command getifaddr as you can see in the error message above. – DarkMath Jun 26 '21 at 12:19
1

@DarkMath The command to run is ipconfig, getifaddr en0 are the parameters. – nohillside Jun 26 '21 at 12:23
1

RE: "or en1, depending on your Mac and your connection." -- Or it could be something else, as on my system it's currently en7. While en0 and en1 at the typical, it really depends on what Mac one has and how it is setup to interface with the LAN. – user3439894 Jun 26 '21 at 13:03
This returns simply nothing for me. The other two solutions work, though. – Martin Braun Jul 13 '21 at 00:09

score 8 · Accepted Answer · edited Dec 07 '22 at 13:13

LOCAL_IP=ifconfig | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}'

sets the variable LOCAL_IP to ifconfig to run an empty command, and sends the empty output of that empty command to the pipe built of | grep "inet " | grep -Fv 127.0.0.1 | awk '{print $2}'. So LOCAL_IP is never set afterwards.

What you probably want to run is

LOCAL_IP=$(ifconfig | grep 'inet ' | grep -Fv 127.0.0.1 | awk '{print $2}')

which can be simplified to

LOCAL_IP=$(ifconfig | awk '/inet /&&!/127.0.0.1/{print $2}')

Unfortunately this will return two rows on Macs which are connected over both Ethernet and WLAN. So it's probably safer to use

LOCAL_IP=$(ifconfig | awk '/inet /&&!/127.0.0.1/{print $2;exit}')

which will pick the first network interface/IP address found.

score 2 · Answer 3 · answered Jun 26 '21 at 18:35

2

Here is another option which may be useful to you.

This command will create a variable with the local IP address.

LOCAL_IP=$(osascript -e "IPv4 address of (system info)")

This command will return the local IP address stored in $LOCAL_IP

echo $LOCAL_IP

answered Jun 26 '21 at 18:35

wch1zpink

7,571

1

This is nice, not having to worry about the BSD Device Name of the network adapter. +1 – user3439894 Jun 26 '21 at 19:26

score 0 · Answer 4 · answered Nov 27 '22 at 16:15

0

You can do it in Python without supplying an interface name:

python -c 'import socket; print(socket.gethostbyname(socket.gethostname()))'

answered Nov 27 '22 at 16:15

Feline

101

How can I get the local IP address in macOS to use in a script?

4 Answers4