Before this change we have a mish-mash of ways to pass field names around for
error generation. Sometimes string fieldnames, sometimes .Prefix(), sometimes
neither, often wrong names or not indexed when it should be.
Instead of that mess, this is part one of a couple of commits that will make it
more strongly typed and hopefully encourage correct behavior. At least you
will have to think about field names, which is better than nothing.
It turned out to be really hard to do this incrementally.
All external types that are not int64 are now marked as int32,
including
IntOrString. Prober is now int32 (43 years should be enough of an initial
probe time for anyone).
Did not change the metadata fields for now.
When etcd is down today we don't specifically handle the error involved,
which means clients get a generic 500 error. This commit adds a formal
error type internally for both WatchExpired and EtcdUnreachable, and
then converts them to api/errors before returning to the client. It also
upgrades the client to retry on any 429 or 5xx error that has a
Retry-After header, instead of just 429.
In combination, this allows the apiserver to exert backpressure on
controllers that are hotlooping. Picked 2 seconds by default, but we
could potentially ramp that up even further in a future iteration.
Omit glog prefix when v < 2, show multiline errors for configuration
problems, add new generic messages for server errors that hide some
complexity that is not relevant for users.
Expose basic filters on an error list to ignore certain error types.
This can be used by client code to ignore errors on common schema
types like "metadata.name" or the NotFound error type.
If a client says they want the name to be generated, a 409 is
not appropriate (since they didn't specify a name). Instead, we
should return the next most appropriate error, which is a 5xx
error indicating the request failed but the client *should* try
again. Since there is no 5xx error that exactly fits this purpose,
use 500 with StatusReasonTryAgainLater set.
This commit does not implement client retry on TryAgainLater, but
clients should retry up to a certain number of times.
