[Planetlab-users] Issue while using vxargs to install library files onto a planetlab node (my sliver)

[Robert Escriva]

On Mon, Jan 30, 2012 at 11:26:48PM -0500, Benoy Varghese wrote:
> Hi,
> 
> To provide a background on my issue, I need to install and run my
> application of multiple planetlab nodes parallely. Henec i am using
> vxargs to issue commands to install and run this application. The
> problem i am facing is when i try to install the library files
> required for my application which require root privileges, vxargs
> seems to get stuck.
> 
> For example, If i need to install a package openssl-devel, i need to
> run the following vxargs command:
> 
> vxargs.py -t 10 -a iplist.txt -o
> /Users/planetlab_launchpad/tmp/result ssh nicta_streaming_bt@{} 'sudo
> yum -y install openssl-devel'
> I get the following error in the output file:
> sudo: no tty present and no askpass program specified
> 
> To resolve this issue i used 'ssh -t' as shown below:
> 
> vxargs.py -t 10 -a iplist.txt -o
> /Users/planetlab_launchpad/tmp/result ssh -t nicta_streaming_bt@{}
> 'sudo yum -y install openssl-devel'
> 
> But running it using vxargs as shown below is causing the tty
> terminal screen to be stuck for a very long time. (even If i use a
> timeout (-t 10 ), the terminal screen exits after timeout, but the
> command is never executed).
> 
> I have tried running the install command as a script in the node and
> then execute it remotely using vxargs, but still the results are
> same. The library is not getting installed.
> 
> Seems to me like it is a problem with using pseudo tty option in
> vxargs.
> 
> Any suggestions on how to resolve this issue is appreciated. Thank
> you.
> 
> Ben

enclose the sudo with "script", e.g.:

    vxargs.py -t 10 -a iplist.txt \
        -o /Users/planetlab_launchpad/tmp/result \
        ssh -t nicta_streaming_bt@{} \
        "script -c 'sudo yum -y install openssl-devel'"

This will allow you to see the output of sudo, and should run the
command.

-Robert