This allows us to interrupt/kill the executed command if it exceeds the
timeout (not implemented by this commit).
Set timeout in Exec probes. HTTPGet and TCPSocket probes respect the
timeout, while Exec probes used to ignore it.
Add e2e test for exec probe with timeout. However, the test is skipped
while the default exec handler doesn't support timeouts.
Add support for terminal resizing for exec, attach, and run. Note that for Docker, exec sessions
inherit the environment from the primary process, so if the container was created with tty=false,
that means the exec session's TERM variable will default to "dumb". Users can override this by
setting TERM=xterm (or whatever is appropriate) to get the correct "smart" terminal behavior.
If a user starts an exec session with a shell and leaves it idle long
enough, they will eventually hit the Kubelet's HTTP server's read/write
timeout of 5 minutes. At this time, the StartExec call to Docker exits,
but if the user requested a TTY, the exec'd process does not exit.
After StartExec finishes, we try to determine the exit code of the
exec'd process, but in this case, we'll never get it. This change exits
the loop after 5 tries if the process is still running.
Add support for pluggable Docker exec handlers. The default handler is
now Docker's native exec API call. The previous default, nsenter, can be
selected by passing --docker-exec-handler=nsenter when starting the
kubelet.
Rodolfo Carvalho