We were logging the command to be executed many times, which made debug
logs very hard to read. Now we do it only once.
Also makes the logged ssh command line cut-and-paste-able (the lack of
which has confused a number of people by now; the problem being that we
pass the command as a single argument to execve(), so it doesn't need an
extra level of quoting as it does when you try to run it by hand).
Pipelining is a *significant* performance benefit, because each task can
be completed with a single SSH connection (vs. one ssh connection at the
start to mkdir, plus one sftp and one ssh per task).
Pipelining is disabled by default in Ansible because it conflicts with
the use of sudo if 'Defaults requiretty' is set in /etc/sudoers (as it
is on Red Hat) and su (which always requires a tty).
We can (and already do) make sudo/su happy by using "ssh -t" to allocate
a tty, but then the python interpreter goes into interactive mode and is
unhappy with module source being written to its stdin, per the following
comment from connections/ssh.py:
# we can only use tty when we are not pipelining the modules.
# piping data into /usr/bin/python inside a tty automatically
# invokes the python interactive-mode but the modules are not
# compatible with the interactive-mode ("unexpected indent"
# mainly because of empty lines)
Instead of the (current) drastic solution of turning off pipelining when
we use a tty, we can instead use a tty but suppress the behaviour of the
Python interpreter to switch to interactive mode. The easiest way to do
this is to make its stdin *not* be a tty, e.g. with cat|python.
This works, but there's a problem: ssh will ignore -t if its input isn't
really a tty. So we could open a pseudo-tty and use that as ssh's stdin,
but if we then write Python source into it, it's all echoed back to us
(because we're a tty). So we have to use -tt to force tty allocation; in
that case, however, ssh puts the tty into "raw" mode (~ICANON), so there
is no good way for the process on the other end to detect EOF on stdin.
So if we do:
echo -e "print('hello world')\n"|ssh -tt someho.st "cat|python"
…it hangs forever, because cat keeps on reading input even after we've
closed our pipe into ssh's stdin. We can get around this by writing a
special __EOF__ marker after writing in_data, and doing this:
echo -e "print('hello world')\n__EOF__\n"|ssh -tt someho.st "sed -ne '/__EOF__/q' -e p|python"
This works fine, but in fact I use a clever python one-liner by mgedmin
to achieve the same effect without depending on sed (at the expense of a
much longer command line, alas; Python really isn't one-liner-friendly).
We also enable pipelining by default as a consequence.
If we request escalation with a password, we start in expecting_prompt
state. If the escalation then succeeds without the password, i.e., the
become_success response arrives, we must explicitly move into the next
state (awaiting_escalation, which immediately goes into ready_to_send),
so that we no longer try to apply the timeout.
Otherwise, we would leak the success notification and eventually
timeout. But if the module response did arrive before the timeout
expired, the "process has already exited" test would do the right
thing by accident (which is why it didn't fail more often).
Fixes#13289
It was set to match the SSH connect timeout. Unfortunately, they would
race when ssh fails to connect, and the connect timeout usually failed.
This led to some misleading error messages.
Fixes#12916
I PR'd a change to pywinrm to allow server certs to be ignored; but it's only on the SSL transport (which we were previously ignoring). For this to work more generally, we're also now pulling the named ansible_winrm_* args from the merged set of host/group vars, not just host_vars.
also remove condition to bypass setting user if user matches current user
this enables forcing user when set to the same user as current user and ignoring .ssh/config
while keeping .ssh/config with current user if nothing is specified.
