them, not in the steady state once they've been created. This makes it
much less likely that users will run into static IP quota issues.
Also add slightly more parallelism to the deletion of load balancers
now that I realize the static IPs can be deleted in parallel with
forwarding rules :)
Not all clients and systems can support SPDY protocols. This commit adds
support for two new websocket protocols, one to handle streaming of pod
logs from a pod, and the other to allow exec to be tunneled over
websocket.
Browser support for chunked encoding is still poor, and web consoles
that wish to show pod logs may need to make compromises to display the
output. The /pods/<name>/log endpoint now supports websocket upgrade to
the 'binary.k8s.io' subprotocol, which sends chunks of logs as binary to
the client. Messages are written as logs are streamed from the container
daemon, so flushing should be unaffected.
Browser support for raw communication over SDPY is not possible, and
some languages lack libraries for it and HTTP/2. The Kubelet supports
upgrade to WebSocket instead of SPDY, and will multiplex STDOUT/IN/ERR
over websockets by prepending each binary message with a single byte
representing the channel (0 for IN, 1 for OUT, and 2 for ERR). Because
framing on WebSockets suffers from head-of-line blocking, clients and
other server code should ensure that no particular stream blocks. An
alternative subprotocol 'base64.channel.k8s.io' base64 encodes the body
and uses '0'-'9' to represent the channel for ease of use in browsers.
Previously we'd just tear everything down and recreate it, which makes
for a pretty bad experience because it causes downtime whenever the
service controller restarts and has to make sure everything is in the
desired state.
This adds more code than I'd prefer, but makes it much cleaner and more
organized than it was before, in my opinion. I didn't bother
parallelizing anything because it's complex enough as it is, right now.
It's consistently passing the existing e2es and worked when I tested
manually, but this could definitely use additional e2e tests and/or some
serious refactoring to make real unit tests feasible. I'll follow up
with one or two e2e tests that make sense (updating an LB or killing the
controller manager, perhaps).
