Change 556683 had a related patch set uploaded (by Michael Große; owner: Michael Große):
[mediawiki/core@master] Expose own IP address in API

https://gerrit.wikimedia.org/r/556683

I note you could do this by forcing a logged-out response, as that reports the IP as the username. There are a few ways to do that. Given that, adding the client IP specifically to meta=userinfo doesn't seem like much of a problem.

On the other hand, that the above works has been reported as a bug ({T70544}) and if T227733: Draft: Masking IP addresses for increased privacy ever happens it would likely break the above methods, so there should probably be an actual resolution of the explicit question as to whether we want this feature available.

To me this seems a bit like the wrong approach. Shouldnt the you are blocked api response comtain all the relavent info about the block, including ip if that is relavent. It seems a bit fragile to require the client to know that for this type of block, users ip is relavent info.

When doing the real action it shows the same result. I may looks a bit better when using errorformat=html, but for intestactions there is no way to define a format

In both cases it is the apierror-blocked message, not the blockedtext message from the task description

It seems a bit fragile to require the client to know that for this type of block, users ip is relavent info.

MediaWiki core shows the IP address for all kinds of blocks, regardless of whether it’s relevant or not; we would do the same.

but for intestactions there is no way to define a format

There is – it obeys the overall errorformat. (But if the errorformat is the default bc, then it says “eew” and uses plaintext instead.)

However –

In both cases it is the apierror-blocked message, not the blockedtext message from the task description

– the API maps “blocked” errors to a different structure, for example the original error

{
    "code": "blocked",
    "key": "blockedtext",
    "params": [
        "[[User:Lucas Werkmeister|‪Lucas Werkmeister‬]]",
        "also block IP address",
        "127.0.0.1",
        "‪Lucas Werkmeister‬",
        5,
        "infinite",
        "‪Eternally blocked user‬",
        "18:09, 5 December 2018"
    ]
}

gets turned into

{
    "code": "blocked",
    "key": "apierror-blocked",
    "params": [],
    "data": {
        "blockinfo": {
            "blockid": 5,
            "blockedby": "Lucas Werkmeister",
            "blockedbyid": 1,
            "blockreason": "also block IP address",
            "blockedtimestamp": "2018-12-05T17:09:57Z",
            "blockexpiry": "infinite"
        }
    }
}

which has the side effect of discarding the IP address, since not all of the original message parameters make it into the blockinfo. If it didn’t do this (and no other kind of error receives such special treatment, as far as I can see), then we would already have all the information we need.

In T240565#5738960, @Lucas_Werkmeister_WMDE wrote:

which has the side effect of discarding the IP address, since not all of the original message parameters make it into the blockinfo.

I note that the IP address isn't really info about the block.

I also note it was added to the message back in 2003. These days the block ID seems likely to be more generally useful than the IP.

and no other kind of error receives such special treatment, as far as I can see

There are a number of other errors that get transformed for historical reasons, but you're right that no others have structured data added.

Ideally the structured data would be added when the message gets created, but tracking down and updating all the creators of "blocked" messages seemed a daunting task. Plus the only way to add structured data to a message is currently kind of hacky; it'll likely be better once we switch to MessageValue.

Change 556683 abandoned by Michael Große:

[mediawiki/core@master] Expose own IP address in API

Reason:

We managed without this patch. (abandoning to make the list of old patches smaller)

https://gerrit.wikimedia.org/r/556683