This is some cleanup that has been needed for a while.
There's still one more step that could usefully be done, which is to
split up our api package into the part that provides the helper
functions and the part that provides the internal types. That can come
later.
The v1beta1 package is now a good example of what an api plugin should
do to version its types.
Because time.Time doesn't work correctly with our YAML package, it is necessary
to introduce a type, util.Time, which serializes correctly to JSON and YAML.
Eventually we would like timestamping to cut across storage implementations;
for now, we set it in each storage.
This commit adds a Binding object. The idea is that schedulers can write
these to cause pods to be asssigned to hosts. I'll provide an implementation
along with a rudimentary scheduler plugin.
This continues k8s' tradition of phrasing all APIs as RESTful handlers.
1. Change names of Pod statuses (Waiting, Running, Terminated).
2. Store assigned host in etcd.
3. Change pod key to /registry/pods/<podid>. Container location remains
the same (/registry/hosts/<machine>/kublet).
Contains breaking API change on api.Status#Details (type change)
Turn Details from string -> StatusDetails - a general
bucket for keyed error behavior. Define an open enumeration
ReasonType exposed as Reason on the status object to provide
machine readable subcategorization beyond HTTP Status Code. Define
a human readable field Message which is common convention (previously
this was joined into Details).
Precedence order: HTTP Status Code, Reason, Details. apiserver would
impose restraints on the ReasonTypes defined by the main apiobject,
and ensure their use is consistent.
There are four long term scenarios this change supports:
1. Allow a client access to a machine readable field that can be
easily switched on for improving or translating the generic
server Message.
2. Return a 404 when a composite operation on multiple resources
fails with enough data so that a client can distinguish which
item does not exist. E.g. resource Parent and resource Child,
POST /parents/1/children to create a new Child, but /parents/1
is deleted. POST returns 404, ReasonTypeNotFound, and
Details.ID = "1", Details.Kind = "parent"
3. Allow a client to receive validation data that is keyed by
attribute for building user facing UIs around field submission.
Validation is usually expressed as map[string][]string, but
that type is less appropriate for many other uses.
4. Allow specific API errors to return more granular failure status
for specific operations. An example might be a minion proxy,
where the operation that failed may be both proxying OR the
minion itself. In this case a reason may be defined "proxy_failed"
corresponding to 502, where the Details field may be extended
to contain a nested error object.
At this time only ID and Kind are exposed
etcd_tools.go is not dependent on the specific implementation
(which is provided by pkg/api). All EtcdHelpers are created
with an encoding object which handles Encode/Decode/DecodeInto.
Additional tests added to verify simple atomic flows.
Begins to break up api singleton pattern.
