In PodConfigNotificationIncremental PodConfig mode, when no pods are available
for a source, the Merge function correctly concluded that neither ADD, UPDATE nor
REMOVE updates are to be sent to the kubelet. But as a consequence the kubelet will
not mark that source as seen.
This is usually not a problem for the apiserver source. But it is a problem for
an empty "file" source, e.g. by passing an empty directory to the kubelet for
static pods. Then the file source will never be seen and the kubelet will stay
in its special not-all-source-seen mode.
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.
