[CentOS] use pssh to restart a service

[Gordon Messmer]

On 10/31/2015 02:04 PM, Tim Dunphy wrote:
> pssh -h es_list   "/bin/sudo -S /bin/systemctl restart elasticsearch"

The default configuration prohibits use if input echo can't be 
disabled.  That means no "-S".

I modify that for users where necessary:

/etc/sudoers.d/myuser:
     Defaults:myuser    !requiretty, visiblepw