compat: Add subnet mask behind IP address to match Docker API

[serverwentdown]

What this PR does / why we need it:

Mismatch between Podman and Docker APIs when listing network containers.

How to verify it

On both Docker and Podman, create a container on a network and run:

curl -X GET --unix-socket /var/run/docker.sock http://d/networks/<id> | jq

Docker (20.10.10):

Podman:

Which issue(s) this PR

Fixes: None

(Sidenote: I'm working on compatibility with k3d)

Special notes for your reviewer:

[TomSweeneyRedHat]

@serverwentdown thanks for the PR. Our CI requires a test to be added with a PR. Could you create one or update one? It would be good to test that the format is as you want it to be.

Changes LGTM otherwise, but I'm not sure if there are dependencies elsewhere for the current format.

[rhatdan]

@Luap99 @mheon @baude PTAL

[Luap99]

One nit, could you also add a test to https://github.com/containers/podman/tree/main/test/apiv2?

[serverwentdown]

@Luap99 I have added an APIv2 test but because the API tests run as rootless, it won't populate the IP address field. I should write an E2E test instead, right? Oddly, the tests started working on my local machine now.

[Luap99]

LGTM

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Luap99, serverwentdown

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[Luap99]

Thanks @serverwentdown, unfortunately you have to rebase to the latest main branch in order to pass the CI tests.

[Luap99]

/lgtm
/hold

[rhatdan]

Forcing merge to save the planet.

[rhatdan]

Thanks @serverwentdown

[serverwentdown]

@rhatdan @Luap99 is there any plans for this bugfix to be released in v3?

[Luap99]

@rhatdan @Luap99 is there any plans for this bugfix to be released in v3?

@mheon PTAL

[rhatdan]

No plans for that now.

[mheon]

Given when this merged, I probably already attempted to backport it to v3.4.2 or v3.4.3, but the patch had cherry-pick conflicts against that branch so I moved on.

[geraldwuhoo]

Has this feature been added in v4? Been waiting on this for k3d on podman.

[Luap99]

@geraldwuhoo It should be in v4.0