Juju expose on k8s doesn't seem to support non-web services

[Barry Price]

I can write a charm to deploy a network service running on an arbitrary TCP/UDP port, the pods deploy correctly and the service works fine on the individual units.

But Juju doesn't seem to be able to set up a Service for us in this use case.

Even with our service ports defined correctly in the pod spec as e.g. TCP/123 or UDP/456, running 'juju expose' seems to ignore them and instead creates an Ingress for TCP/80.

[John A Meinel (jameinel)]

We dug into this a bit on our end, and the track led us down:
https://kubernetes.io/docs/concepts/services-networking/ingress/#ingress-rules

Really only defines ways of exposing HTTP workloads. There doesn't seem to be anything in Ingress rules that would expose alternative ports/sockets like UDP for Bind.

That said, Nginx is one of the most common ingress controllers, and it is happy to support configuration that exposes raw TCP or UDP:
https://kubernetes.github.io/ingress-nginx/user-guide/exposing-tcp-udp-services/

Do we know if there are plans inside K8s to update the Ingress definitions to expose services other-than-http?
In the meantime, could we have our Nginx ingress controller charm have a 'expose' sort of relation, that you could then relate your Bind charm to Nginx and have it ask for Nginx to get the extra configuration?

[John A Meinel (jameinel)]

We should also look into not utilizing an Ingress controller, but just a
Service description for Bind:
https://kubernetes.io/docs/concepts/services-networking/service/

On Wed, Aug 5, 2020 at 1:05 PM John A Meinel <email address hidden>
wrote:

> We dug into this a bit on our end, and the track led us down:
>
> https://kubernetes.io/docs/concepts/services-networking/ingress/#ingress-rules
>
> Really only defines ways of exposing HTTP workloads. There doesn't seem
> to be anything in Ingress rules that would expose alternative
> ports/sockets like UDP for Bind.
>
> That said, Nginx is one of the most common ingress controllers, and it is
> happy to support configuration that exposes raw TCP or UDP:
>
> https://kubernetes.github.io/ingress-nginx/user-guide/exposing-tcp-udp-services/
>
> Do we know if there are plans inside K8s to update the Ingress definitions
> to expose services other-than-http?
> In the meantime, could we have our Nginx ingress controller charm have a
> 'expose' sort of relation, that you could then relate your Bind charm to
> Nginx and have it ask for Nginx to get the extra configuration?
>
> --
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> https://bugs.launchpad.net/bugs/1889703
>
> Title:
> k8s ingress doesn't seem to support non-web services
>
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