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The idea is to make this script run without needing to type any passwords of the hosts (written down in the Hosts.txt file). Right now, when I'm running this, I get a Permission denied, please try again. as an answer. 

#!/bin/bash

[[ -z "${1}" ]] && OUT_FILE="WhereTheAnswearIsGoing.txt" || OUT_FILE="$1"
[[ -z "${2}" ]] && IN_FILE="Hosts.txt" || IN_FILE="$2"

while IFS= read -r host; do
        indication="$(sshpass -pfootbar ssh -p 2222 -o StrictHostKeyChecking=no -n "$host" 'who -b' | awk '{print $(NF-1)" "$NF}')"
        printf '%-14s %s\n' "$indication" "$host" >> "$OUT_FILE"
done < "$IN_FILE"

Sorry if this question is unclear but I don't know much about things like these.

Zanna
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Ludvig
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1 Answers1

10

It looks the message Permission denied, please try again. is generated by the SSH client. The password should be quoted to escape the special meaning of characters as $, !, etc. (ref):

sshpass -p 'footbar' ...

Or you can use a file where the password to be stored (source):

sshpass -f "/path/to/passwordfile" ...

enter image description here

However, I remember, this is a script from my previous answer where I mentioned that: "Note here is assumed there is ~/.ssh/config file and additional parameters as -p 2222 are not needed (reference)." What I meant was:

The better solution is to (1) setup Key based SSH authentication, (2) create ~/.ssh/config file and (3) modify the script to work with this setup.

1. Setup Key based SSH authentication (source).

  • Generating RSA Keys and don't enter passphrase:

      mkdir ~/.ssh
  chmod 700 ~/.ssh
  ssh-keygen -t rsa -b 4096
  chmod 600 ~/.ssh/id_rsa

  • Transfer Client Key to each Host (please note the quote marks):

      ssh-copy-id "<username>@<host> -p <port_nr>"

  • Now you should be able to connect to the server(s) without password:

      ssh <username>@<host> -p <port_nr>

  • Once this works, you could disable the password authentication (that is less secure method) by editing the file /etc/ssh/sshd_config of each host machine in this way:

      #PasswordAuthentication yes
  PasswordAuthentication no

2. Create ~/.ssh/config file. (Read also: How do I add multiple machines with the same configuration to ~/.ssh/config?)

  • The content of the file ~/.ssh/config could look as this (host-i is object of your choice):

      Host host-1
      HostName <domain-or-IP-address>
      IdentityFile ~/.ssh/id_rsa
      User <username>
      Port 2222
      # other parameters...

    Host host-2
      HostName <domain-or-IP-address>
      IdentityFile ~/.ssh/id_rsa
      User <username>
      Port 2222
      # other parameters...
    

    Host host-3...

  • Change the file permissions:

      chmod 600 ~/.ssh/config

  • Now you should be able to connect to each of these hosts by a command as:

      ssh host-1

3.A. You can keep using the above scrip with a little modification:

#!/bin/bash

[[ -z $1 ]] && OUT_FILE="WhereTheAnswearIsGoing.txt" || OUT_FILE="$1"
[[ -z $2 ]] && IN_FILE="Hosts.txt" || IN_FILE="$2"


while IFS= read -r host; do
        indication="$(ssh -n "$host" 'who -b' | awk '{print $(NF-1)" "$NF}')"
        printf '%-14s %s\n' "$indication" "$host" >> "$OUT_FILE"
done < "$IN_FILE"

In this case the Hosts.txt file should be:

host-1
host-2
host-3

3.B. Or you can modify the script in more general way:

#!/bin/bash

Collect the user's input, and if it`s empty set the default values


[[ -z $1 ]] && OUT_FILE="WhereTheAnswearIsGoing.txt" || OUT_FILE="$1"


Provide the list of the hosts as an array


HOSTS=("host-1" "host-2" "host-3")


for host in "${HOSTS[@]}"; do
    indication="$(ssh -n "$host" 'who -b' | awk '{print $(NF-1)" "$NF}')"
    printf '%-14s %s\n' "$host" "$indication" >> "$OUT_FILE"
done
pa4080
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