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).
Add tests to watch behavior in both protocols (http and websocket)
against all 3 media types. Adopt the
`application/vnd.kubernetes.protobuf;stream=watch` media type for the
content that comes back from a watch call so that it can be
distinguished from a Status result.
... and a quick doc on how to run them
```
$ godep go test ./pkg/apiserver -benchmem -run=XXX -bench=BenchmarkWatch
PASS
BenchmarkWatchHTTP-8 20000 95669 ns/op 15053 B/op 196 allocs/op
BenchmarkWatchWebsocket-8 10000 102871 ns/op 18430 B/op 204 allocs/op
```
A NegotiatedSerializer is passed into the API installer (and
ParameterCodec, which abstracts conversion of query params) that can be
used to negotiate client/server request/response serialization. All
error paths are now negotiation aware, and are at least minimally
version aware.
Watch is specially coded to only allow application/json - a follow up
change will convert it to use negotiation.
Ensure the swagger scheme will include supported serializations - this
now includes application/yaml as a negotiated option.
The pending codec -> conversion split changes the signature of
Encode and Decode to be more complicated. Create a stub helper
with the exact semantics of today and do the simple mechanical
refactor here to reduce the cost of that change.
pkg/service:
There were a couple of references here just as a reminder to change the
behavior of findPort. As of v1beta3, TargetPort was always defaulted, so
we could remove findDefaultPort and related tests.
pkg/apiserver:
The tests were using versioned API codecs for some of their encoding
tests. Necessary API types had to be written and registered with the
fake versioned codecs.
pkg/kubectl:
Some tests were converted to current versions where it made sense.
Dependency chain is now api -> api/rest -> apiserver. Makes the
interfaces much cleaner to read, and cleans up some inconsistenties
that crept in along the way.
Allows us to define different watch versioning regimes in the future
as well as to encode information with the resource version.
This changes /watch/resources?resourceVersion=3 to start the watch at
4 instead of 3, which means clients can read a resource version and
then send it back to the server. Clients should no longer do math on
resource versions.
