JUNOS, Scripting and SSH-AGENT

In two previous blog entries I talked about leveraging ssh-agent with scripting. Below is an example script I use to run different commands on Junos based routers.

This particular script is menu driven from the terminal prompt. Beyond the menu the script is non-interactive. It is plausible to write a script that will request user input based on some condition learned by the script; so for this reason scripts can be interactive unlike the below script.

The way I see it, your imagination and vision is the only limit to what you can achieve in computing.

So, please reference the two following blog entries to setup the ssh-agent for accessing a Junos based platform.
– JUNOS, SSH-KEY Authentication (the how)
– Leveraging ssh-agent and Junos based routers (the why)

To run scripts against a Junos based router, the ssh-agent is not required; however using an ssh-agent is convenient and a time saver.

I have several lab routers that I work with and not all of them are always on and running. The following script does a ping across a range of IP addresses to check if they send an ICMP echo-reply. If they do, the script will log into the router and issue a command.

Here is the script.

#!/usr/bin/env bash
################################################
# File Name: junos_request_system_halt.sh
# Created On: 11/17/2012 Jeff Neuffer Jr
# Updated On: $Id: junos_request_system_halt.sh 102 2012-11-21 15:28:21Z jneuffer $
#
# Note: Purpose is to sweep a range of IP addresses and issue a command
#
#
################################################
#
SCRIPT_VERSION='0.2.1';

# Lab hosts range from .200 - .254
HOSTS=(
172.16.155.200
172.16.155.201
172.16.155.202
172.16.155.203
172.16.155.204
172.16.155.205
172.16.155.206
172.16.155.207
172.16.155.208
172.16.155.209
172.16.155.210
172.16.155.211
172.16.155.212
172.16.155.213
172.16.155.214
172.16.155.215
172.16.155.216
172.16.155.217
172.16.155.218
172.16.155.219
172.16.155.220
172.16.155.254
);
#HOSTS=( 172.16.155.200 172.16.155.201 172.16.155.202 );
#HOSTS=( 172.16.155.200 );

run_command()
{
echo;echo;
for a in ${HOSTS[@]}; do
  # the following ping is used to determine which VM is "alive"
  ping -c 1 -t 1 -n $a > /dev/null 2>&1;
  if [[ $? -gt 0 ]]; then
    echo "$a <-- No Reply"
  else
    echo "$a <-- Alive"
    if [[ "$the_command" == "jhalt" ]]; then
      ssh $a "request system halt"
     sleep 8
    elif [[ "$the_command" == "jreboot" ]]; then
      ssh $a "request system reboot"
      sleep 58
    else
      echo;echo "nothing matches ($the_command)";echo
    fi
  sleep 2
  fi
done
echo;echo;
}

continue=yes
while [ "$continue" = yes ]
do
  echo; echo;
  echo "Send Junos Command ($SCRIPT_VERSION)";
  echo "--------------------------------------------";
  echo;
  echo " 1) Halt (request system halt)";
  echo " 2) Reboot (request system reboot)";

  echo " 9) Quit";
  read -p "Select an option [1-7,9]: " ANSWER

  if [[ "$ANSWER" == 1 ]]
  then
    the_command="jhalt";
    run_command;
    continue=yes;
  elif [[ "$ANSWER" == 2 ]]
  then
    the_command="jreboot";
    run_command;
    continue=yes;

  elif [[ "$ANSWER" == [9Qq] ]]
  then
    echo "Quiting"; echo;echo;
   continue=no;
  else
    clear;
    continue=yes;
  fi
done

This is the output from the script. Notice that for each login to a router a password is not requested.