Checking IDs against containers should be explicitly optional

[squaremo]

Not assigning an IP because a container is not running breaks the Docker plugin, because it cannot supply a container ID, only an endpoint ID.

[rade]

Simply feed ipam an id that syntactically isn't a full container id. As we do with weave:expose.

[squaremo]

Yes, I came to that conclusion. That seems pretty grubby.

[squaremo]

(not to mention undocumented?)

[rade]

None of the IPAM APIs are documented.

[squaremo]

How does that even work? If not by coincidence.

[rade]

where's the coincidence?

[squaremo]

OK I take it back. Just a grubby hack, not a coincidence.

[rade]

Suggestions for non-grubby non-hacks welcome. Feel free to repurpose this issue for that; otherwise close it.

[squaremo]

Repurposing: Instead of assuming anything that looks like a container ID (e.g., a libnetwork endpoint ID) is in fact a container ID, and refusing to issue an IP for it, IPAM should be told when it should do this and when not. The option could be supplied, for example, as a form field in the POST (or a querystring param, or either).

For the purposes of being a general API, it would make more sense if the default was not to check; but it is more convenient for the weave script (and not a terrible burden elsewise) if it defaults the other way.

[rade]

NB: this issue also applies to DNS.

[tomwilkie]

For DNS, can I assume all non-empty containerids are intended to be
containerids? Or is the intention to pass endpoint ids to DNS also?

On Friday, 3 July 2015, Matthias Radestock [email protected] wrote:

NB: this issue also applies to DNS.

—
Reply to this email directly or view it on GitHub
#971 (comment).

[squaremo]

Or is the intention to pass endpoint ids to DNS also?

At the minute the plugin has to watch docker for containers coming and going, so it uses container IDs. If service discovery is opened up as an extension point, it'll be an endpoint ID (or some other). I recommend the approach given above rather than trying to guess from the name, which was after all the original complaint.

[rade]

For DNS, can I assume all non-empty containerids are intended to be containerids?

No, you cannot assume that. And the current DNS code doesn't.

[rade]

I recommend the approach given above rather than trying to guess from the name

That is this issue. For #826, let us keep whatever API is on master.