How to pass a pasta argument containing a comma when using --network=pasta ?

[eriksjolund]

This is more of a curious question. I don't have any specific use case in mind.

Is is possible to pass pasta argument containing a comma when using --network=pasta ?

The problem is that --network=pasta uses commas to separate arguments.

Quote:
"Options described in pasta(1) can be specified as comma-separated arguments."
from
https://docs.podman.io/en/latest/markdown/podman-run.1.html

Experiment

Is it possible to achieve pasta -T 3000,3001 ?

I did an experiment where I added a backslash in front of the comma.

1. Run command

   podman run --rm --network 'pasta:-T,3000\,3001' -d --name test2  docker.io/library/alpine sleep 60
   

2. In another shell run command

   ps axuw| grep /usr/bin/pasta
   

   The following output is printed

   test3       1687  0.0  0.0 191696  2496 pts/2    S+   07:00   0:00 /usr/bin/pasta --config-net -T 3000\ 3001 --dns-forward 169.254.1.1 -t none -u none -U none --no-map-gw --quiet --netns /run/user/1003/netns/netns-6490543a-7838-0ce3-0111-3872436e7631 --map-guest-addr 169.254.1.2
   test3       1762  0.0  0.0   3800  1912 pts/5    S+   07:15   0:00 grep --color=auto /usr/bin/pasta
   

result: In the output from ps auxw there is -T 3000\ 3001

I had hoped to see -T 3000,3001

Side note 1: There was a question about this in the podman chat https://discord.com/channels/852634929845239818/852634929845239824/1428451075069055097

Side note 2:
Looking at the source code it seems it is not possible to pass a pasta argument containing a comma:

podman/pkg/specgen/namespaces.go

Line 394 in f2a559a

networkOptions[key] = strings.Split(options, ",")

[Luap99]

Yeah it is not possible via cli, I guess you can make it work via containers.conf.

Adding escaping would be required though IMO it makes the thing much more awkward and complicates the parsing a fair bit. Is there actually a strong need for comma in pasta(1) arguments? You can always specific -T multiple times for several ports which should have the same effect?

cc @sbrivio-rh

[eriksjolund]

Is there actually a strong need for comma in pasta(1) arguments?

I don't have any specific use case in mind. I was just curious.

[sbrivio-rh]

I mean, there's one case, see --tcp-ports in pasta(1). Sets of ports or port ranges (not port ranges themselves) need commas in pasta, and there might be users who find that syntax more convenient.

Should we perhaps escape with an extra comma? Two commas are always invalid, and if they were ever to become valid, one can use three. Anything else would get quite messy in a shell.