[jira] [Updated] (OOZIE-2638) Ssh action fails if .bashrc contain a script

["Attila Sasvari (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/OOZIE-2638?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Attila Sasvari updated OOZIE-2638:
----------------------------------
    Labels: docs  (was: )

> Ssh action fails if .bashrc contain a script 
> ---------------------------------------------
>
>                 Key: OOZIE-2638
>                 URL: https://issues.apache.org/jira/browse/OOZIE-2638
>             Project: Oozie
>          Issue Type: Improvement
>            Reporter: Attila Sasvari
>            Priority: Minor
>              Labels: docs
>
> Right now SshActionExecutor runs the SCP command as part of executing the SSH action.
> As a consequence, if the target SSH user has some command/script in their rc file (e.g. .bashrc) that outputs to the standard output in non-interactive sessions, the action will fail with 
> UNKOWN_ERROR: Not able to perform operation [scp -o PasswordAuthentication=no -o KbdInteractiveDevices=no -o StrictHostKeyChecking=no -o ConnectTimeout=20 ...
> It turns out, it is the way how openssh SCP works. So if something else  is written to stdout (for example an ls in .bashrc), it will fail and return 1.
> See https://github.com/apache/oozie/blob/master/core/src/main/java/org/apache/oozie/action/ssh/SshActionExecutor.java#L695
> To overcome this limitation, we should investigate alternatives that do not have this limitation. 
> JSch (https://mvnrepository.com/artifact/com.jcraft/jsch) can be such an alternative.
> References:
> - Is this shell interactive? https://www.gnu.org/software/bash/manual/html_node/Is-this-Shell-Interactive_003f.html
> - https://github.com/openssh/libopenssh/blob/master/ssh/scp.c
> - http://stackoverflow.com/questions/12440287/scp-doesnt-work-when-echo-in-bashrc/12442753#12442753
> - https://bugzilla.redhat.com/show_bug.cgi?id=20527
> - http://unix.stackexchange.com/questions/120080/what-are-ssh-tty-and-ssh-connection
> * As a workaround, one could detect in their .bashrc (or the corresponding rc file of the shell they prefer) if they are in an SCP / non-interactive session, do not echo anything on noninteractive shell.
> For example, if I put the following into my .bashrc 
> [[ $- == i ]] || return
> SCP will work. But there can be situations where commands must be run. We could silent them (by redirecting stderr/stdout), but I believe it is not so convenient for a lot of users.



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