Enhance the Kaniko builder

[r2d4]

Namely

• Surface some of the flags that have been added since the initial release
• The option to use an existing cluster secret instead of creating one from a keyfile passed in.
• Generate unique pod names
• Configurable namespace for kaniko builder

cc @sharifelgamal @priyawadhwa

[JonnyBGod]

Also would be good to be able to use Kaniko by passing just the local context and destination skipping the need for a GC Bucket

[dlorenc]

A few other improvements:

• Support a configurable namespace for kaniko
• Improve secret management (specifying existing secrets, etc.)
• Generate unique names for the pod (in case of errors with earlier versions, etc.)

[dlorenc]

A few other things left to do. Updated in the top comment to track in one spot.

[dlorenc]

Also would be good to be able to use Kaniko by passing just the local context and destination skipping the need for a GC Bucket

I think that's more of a kaniko limitation than a skaffold issue - would you mind opening an issue in that repo with the use case?

[priyawadhwa]

You can pass in a local directory as the build context to kaniko with the --context flag. I think skaffold would just have to mount the local context into the pod to be able to use it.

[dlorenc]

I think the problem would be first getting the source from the local machine into the cluster and onto the node,although it's true skaffold might be able to do that before starting the kaniko container.

[r2d4]

Closing this with #803, which upgrades the version to v0.2.0. We can track more specific feature requests in another issue.