add delete_collection api

[russell]

Delete collection is like getting a list, except it triggers a delete of the
resources. It returns a list of all resources that match the call.

I based this of the get entities like get_pods because it's roughly
the same API except as a side effect it deletes all the resources.

[cben]

lib/kubeclient.rb:481:101: C: Layout/LineLength: Line is too long. [105/100]

Opened #547 to add support resource_version_match in other actions.

[cben]

Sorry for delay. Generally looks good 👍

Please document this in README. Including what it returns (the content of the deleted resources?) because it's not entirely obvious.

Let's see, how this compares to delete-single interface:

delete_foo('name', 'namespace', opts)    # namespaced
delete_foo('name', nil, opts)            # global
delete_foos(namespace: 'ns', **opts)     # namespaced
delete_foos(**opts)                      # global

Not consistent but it mirrors the existing inconsistency between get_foo and get_foos.
And I do like keyword arguments in new APIs. So no objection 👍

• Is this dangerous that this is only 1 letter off from deleting a single resource?
  If I meant delete_pod but accidentally mistype delete_pods('mypod', 'ns') will it error, or delete stuff?

Another point worth documenting: What happens if you omit namespace: with a namespaced resource, e.g. pods — will it error, or delete all pods in all namespaces?
I see the unit test covers exactly this scenario — it sends DELETE request to http://localhost:8080/api/v1/pods. (makes sense, build_namespace_prefix has no idea whether it's used with a resource supposed to be namespaced)
But will that work? In k8s API I only see documentation for DELETE /api/v1/namespaces/{namespace}/pods.

• can you please add a test case using a namespace: param?

[russell]

Sorry for delay. Generally looks good 👍

I have rebased the PR since you last looked. DW, i'm even slower ;)

Please document this in README. Including what it returns (the content of the deleted resources?) because it's not entirely obvious.

It returns the same thing as doing a get_foos and the doc suggests looking at get to understand it's potential return values.

• Is this dangerous that this is only 1 letter off from deleting a single resource?
  If I meant delete_pod but accidentally mistype delete_pods('mypod', 'ns') will it error, or delete stuff?

maybe, but it's no more dangerous than any other api IMHO.

if you mistype it you get

[5] pry(main)> client.delete_pods('foo', namespace: 'default')
ArgumentError: wrong number of arguments (given 2, expected 0..1)
from /Users/rsim/Code/zendesk/kubeclient/lib/kubeclient.rb:313:in `block (2 levels) in define_entity_methods'
[6] pry(main)> client.delete_pods('foo', 'default')
ArgumentError: wrong number of arguments (given 2, expected 0..1)
from /Users/rsim/Code/zendesk/kubeclient/lib/kubeclient.rb:313:in `block (2 levels) in define_entity_methods'

so it won't accept any positional argument for a name.

Another point worth documenting: What happens if you omit namespace: with a namespaced resource, e.g. pods — will it error, or delete all pods in all namespaces? I see the unit test covers exactly this scenario — it sends DELETE request to http://localhost:8080/api/v1/pods. (makes sense, build_namespace_prefix has no idea whether it's used with a resource supposed to be namespaced) But will that work? In k8s API I only see documentation for DELETE /api/v1/namespaces/{namespace}/pods.

Nothing, you get an error

Kubeclient::HttpError: the server does not allow this method on the requested resource

• can you please add a test case using a namespace: param?

I have updated all test cases to handle namespace: because it's the only working form of the method

[cben]

CI failures are just flaky timeouts. Close-cycling to re-run.