We should be following the same rules for Stream() as the normal body
request flow.
Also add slightly more output on a server error - in the future we may
want to clean this up but it's potentially hiding bad responses.
Currently if there is an error (not found) the error printed out
is to do with the inablity to convert an empty body into the expected json.
This patch will fill in the err correctly.
example of before (with NotFound error):
$ kubectl top node
failed to unmarshall heapster response: json: cannot unmarshal object into Go value of type []v1alpha1.NodeMetrics
Now:
$ kubectl top node
the server could not find the requested resource (get services http:heapster:)
Automatic merge from submit-queue
Remove implicit Prometheus metrics from client
**What this PR does / why we need it**: This PR starts to cut away at dependencies that the client has.
**Release note**:
<!-- Steps to write your release note:
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```release-note
The implicit registration of Prometheus metrics for request count and latency have been removed, and a plug-able interface was added. If you were using our client libraries in your own binaries and want these metrics, add the following to your imports in the main package: "k8s.io/pkg/client/metrics/prometheus".
```
cc: @kubernetes/sig-api-machinery @kubernetes/sig-instrumentation @fgrzadkowski @wojtek-t
Also allow a new AcceptContentTypes field to allow the client to ask for
a fallback serialization when getting responses from the server. This
allows a new client to ask for protobuf and JSON, falling back to JSON
when necessary.
The changes to request.go allow error responses from non-JSON servers to
be properly decoded.
The codec factory should support two distinct interfaces - negotiating
for a serializer with a client, vs reading or writing data to a storage
form (etcd, disk, etc). Make the EncodeForVersion and DecodeToVersion
methods only take Encoder and Decoder, and slight refactoring elsewhere.
In the storage factory, use a content type to control what serializer to
pick, and use the universal deserializer. This ensures that storage can
read JSON (which might be from older objects) while only writing
protobuf. Add exceptions for those resources that may not be able to
write to protobuf (specifically third party resources, but potentially
others in the future).
