On 06:19 pm, rodrigc@crodrigues.org wrote:

Hi,

I have a very similar question to the one that Vye Wilson recently asked, "Subject: What is The Correct Way to Close a Twisted Conch SSH Connection?"

I am using Twisted Conch to write a program that ssh's into multiple machines and executes a single command.

I am basically trying to do the equivalent of:

for host in host1 host2 host3 do ssh user@host "cat /etc/hosts" done

To start things off, I took http://twistedmatrix.com/documents/current/conch/examples/sshsimpleclient.py and started modifying it. Here is the code which I have:

http://pastebin.com/RXhjUcrS

The problem is, I can't figure out how to tell when a command has completed, so that I can call reactor.stop().

Not in the code example I posted above, I tried to use a DeferredList by following the example code in this blog post:

http://technicae.cogitat.io/2008/06/async-batching-with-twisted- walkthrough.html

but I ran into the same problem where I couldn't figure out how to tell when my command over SSH had terminated.

As a kluge, I called reactor.callLater() with a timeout of 20 seconds, and then called reactor.stop().

Any ideas as to what I am doing wrong? Where in the Conch framework can I tell when a command over SSH has finished?

You can't tell when a command has finished. Commands are run in the context of a channel. You can tell when a channel has closed because its `closed` method is called. You might find this spike of an SSH command endpoint interesting: http://twistedmatrix.com/~exarkun/sshendpoint.py Also note this is something that I would like to be better supported in Conch: http://twistedmatrix.com/trac/ticket/4698 Jean-Paul

On 06:19 pm, rodrigc@crodrigues.org wrote:

Hi,

I have a very similar question to the one that Vye Wilson recently asked, "Subject: What is The Correct Way to Close a Twisted Conch SSH Connection?"

I am using Twisted Conch to write a program that ssh's into multiple machines and executes a single command.

I am basically trying to do the equivalent of:

for host in host1 host2 host3 do ssh user@host "cat /etc/hosts" done

To start things off, I took http://twistedmatrix.com/documents/current/conch/examples/sshsimpleclient.py and started modifying it. Here is the code which I have:

http://pastebin.com/RXhjUcrS

The problem is, I can't figure out how to tell when a command has completed, so that I can call reactor.stop().

Not in the code example I posted above, I tried to use a DeferredList by following the example code in this blog post:

http://technicae.cogitat.io/2008/06/async-batching-with-twisted- walkthrough.html

but I ran into the same problem where I couldn't figure out how to tell when my command over SSH had terminated.

As a kluge, I called reactor.callLater() with a timeout of 20 seconds, and then called reactor.stop().

Any ideas as to what I am doing wrong? Where in the Conch framework can I tell when a command over SSH has finished?

You can't tell when a command has finished. Commands are run in the context of a channel. You can tell when a channel has closed because its `closed` method is called. You might find this spike of an SSH command endpoint interesting: http://twistedmatrix.com/~exarkun/sshendpoint.py Also note this is something that I would like to be better supported in Conch: http://twistedmatrix.com/trac/ticket/4698 Jean-Paul