Addresses issue #51. Makes versioning in poolmgr explicit, so its
cache needs no invalidation on version update. Functions in poolmgr
are always cached by name and UID.
Router now updates implictly versioned routes with the latest version
of a function.
This means that users will see requests to implicitly-versioned routes
go to the latest version of a function within 3 seconds. (Those 3 sec
will go away when we use a real watch instead of polling the
controller.)
There's no change in behaviour for routes that explictly specify a
function UID.
These routes allow us to call any function without explicitly defining
a route for them. TODO: if we can serve these routes from a separate
instance of router (controlled by a commandline flag or env var), we'd
be able to keep this instance of the router "private" by not assigning
it a loadbalancer/nodeport or other externally-visible service.
Poolmgr needs to know usage statistics for a function's pod. This
change asynchronously taps poolmgr API when router uses a service.
Poolmgr can use this information to control pod expiry. It may also
be useful later as one of the metrics for autoscaling.
Create an implementation of http.RoundTrip which does retries --
RetryingRoundTripper. K8s services seem to timeout for about ~1-2 sec
after they're created even when the pods being routed to are ready to
serve requests.
Router uses poolmgr to specialize pods when necessary.
Router uses controller to get the list of triggers to listen for. For
now this integration is pretty crappy -- we just poll the controller
every few seconds and cache the result. The right way would be to
have some sort of watch API on the controller and use that. Or maybe
share access to etcd directly.
Soam Vasani