Re: [Fab-user] Automating remote interactive shell

[Claudius Heine]

Hi Jeff,

On Mon, 2017-03-13 at 09:13 -0700, Jeff Forcier wrote:
> Hi Claudius,
> 
> First, there is a very basic responder functionality currently
> implemented, the 'env.prompts' setting:
> 
>     http://docs.fabfile.org/en/1.13/usage/env.html#prompts
> 
> If I had to guess, I'd guess it's too simple for a "fully automatic"
> interaction with a serial console, but it's worth trying if you
> haven't already.

Hmm... Yes, I think its a bit limiting when you only have a 1:1 mapping
for prompt to input. It would be great when those sub-shells are
treated the same as the the rest of the program. So if something like
"run" or "sudo" is available in this shell, then use it, otherwise just
use something like pexpect. I would try to implement something like
shell capabilities that can be set in the shell-context. Maybe even
being able to automate the input to a python shell on the remote target
;) Not sure how useful that would be tough.

> Second, stronger expect-like behavior is on the roadmap; version 2
> (alpha out very soon!) is built on the Invoke library, which has its
> own "2.0" rewrite of the above feature, as 'watchers':
> 
>     http://docs.pyinvoke.org/en/latest/concepts/watchers.html
>     http://docs.pyinvoke.org/en/latest/api/watchers.html#invoke.watch
> ers.StreamWatcher
> 
> I haven't needed anything more complex yet than the sudo-oriented
> FailingResponder yet, but as you can see from the generic
> StreamWatcher class, the intent is to allow for pretty much any
> "examine output streams, yield responses" use case (and for users to
> write their own instead of being limited to what's in core; though of
> course any generally useful patches are likely to be accepted.)

Oh great, I will take a look at it.

I think that could be done generic enough to be useful for upstream.

Maybe its possible to have a class with the invoke.context.Context
methods + pexpect style ones that uses the builder pattern or similar
to create a watcher that then responds to the program output.

Cheers,
Claudius

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