Channels stdoutChan and stderrChan still receive messages after they are closed resulting in messy output

[christianruhstaller]

Output:

======CMD======
exit 0
======END======
out: 
err: 
err: 
out: 
out: 
out: 
out: 
err: 
err: 
err: 
out: 
err: 
out: 
out: 
out: 
out: 
err: 
err: 
err: 
out: 
==============================================
✅ Successfully executed commands to all host.
==============================================

The problem is that the receiving part does not check if the received message has the status "ok":

• https://github.com/appleboy/drone-ssh/blob/1dcc9acbe58edfbf2d1a80357dfcfc8bd5b49640/plugin.go#L129
• https://github.com/appleboy/drone-ssh/blob/1dcc9acbe58edfbf2d1a80357dfcfc8bd5b49640/plugin.go#L131

With the following fix the problem can be bypassed on the client side:

case outline, ok := <-stdoutChan:
if ok {
	p.log(host, "out:", outline)
}

case errline, ok := <-stderrChan:
if ok {
	p.log(host, "err:", errline)
}

The problem started with following pull request from easyssh-proxy: https://github.com/appleboy/easyssh-proxy/pull/66

If you step through the code the channels get closed and still receive some messages after. I could not figure out from which part of the code the messages come, after the channel was closed. It seems that there is still a race condition which leads to this behavior?

In our specific case the empty err and out messages where so large that we ran into an timeout and the pipeline cancelled.