Upgrade mod dependencies

[alculquicondor]

Currently, the operator builds against the 1.15 k8s libraries. Note that currently the oldest supported version of k8s is 1.19

Another dependency is kubeflow/common 0.3.3, which builds against k8s 1.16 libraries. 0.3.4 builds against 1.19

So we could at least upgrade to 1.19 dependencies. This should make it simpler to introduce more dependencies such as controller-runtime for integration and E2E testing #233

However, there is one problematic dependency: kube-batch. While volcano has builds against k8s 1.19, kube-batch (deprecated project) only has builds against 1.16. This dependency is used in the v1alpha2 controller. Hopefully we can still build it using "replace" directives. It might be possible given that we only use the listers from it.

[alculquicondor]

cc @terrytangyuan

[terrytangyuan]

Possibly related: #323

[alculquicondor]

So I gave it a try, and it seems that volcano is fine (it has a version that builds against 1.19).

The problem is kube-batch, used in v1alpha2. I suppose it's not safe to migrate v1alpha2 from kube-batch to volcano, right?

[alculquicondor]

I tried to upgrade to 1.18, 1.17 and even 1.16. In all of them kube-batch fails to build.

Since this dependency nightmare might limit our abilities to iterate the v1 controller, I propose we move it to a separate module https://blog.golang.org/v2-go-modules

Or maybe I can just have the new controller proposed in #360 in the new module, solving the question about keeping the old and new "v1" controllers.

[alculquicondor]

The dependencies were upgraded for the v2 controller #370

/close

[google-oss-robot]

@alculquicondor: Closing this issue.

In response to this:

The dependencies were upgraded for the v2 controller #370

/close

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