I need to collect user information from 100 remote servers. We have public/private key infrastructure for authentication, and I have configured ssh-agent command to forward key, meaning i can login on any server without password prompt (auto login).
Now I want to run a script on all server to collect user information (how many user account we have on all servers).
This is my script to collect user info.
#!/bin/bash
_l="/etc/login.defs"
_p="/etc/passwd"
## get mini UID limit ##
l=$(grep "^UID_MIN" $_l)
## get max UID limit ##
l1=$(grep "^UID_MAX" $_l)
awk -F':' -v "min=${l##UID_MIN}" -v "max=${l1##UID_MAX}" '{ if ( $3 >= min && $3 <= max && $7 != "/sbin/nologin" ) print $0 }' "$_p"
I don't know how to run this script using ssh without interaction??
Since you need to log into the remote machine there is AFAICT no way to do this "without ssh". However, ssh accepts a command to execute on the remote machine once logged in (instead of the shell it would start). So if you can save your script on the remote machine, e.g. as ~/script.sh, you can execute it without starting an interactive shell with
$ ssh remote_machine ~/script.sh
Once the script terminates the connection will automatically be closed (if you didn't configure that away purposely).
Sounds like something you can do using expect.
http://linux.die.net/man/1/expect
Expect is a program that "talks" to other interactive programs according to a script. Following the script, Expect knows what can be expected from a program and what the correct response should be.
If you've got a key on each machine and can ssh remotehost from your monitoring host, you've got all that's required to collect the information you've asked for.
#!/bin/bash
servers=(wopr gerty mother)
fmt="%s\t%s\t%s\n"
printf "$fmt" "Host" "UIDs" "Highest"
printf "$fmt" "----" "----" "-------"
count='awk "END {print NR}" /etc/passwd' # avoids whitespace problems from `wc`
highest="awk -F: '\$3>n&&\$3<60000{n=\$3} END{print n}' /etc/passwd"
for server in ${servers[#]}; do
printf "$fmt" "$server" "$(ssh "$server" "$count")" "$(ssh "$server" "$highest")"
done
Results for me:
$ ./doit.sh
Host UIDs Highest
---- ---- -------
wopr 40 2020
gerty 37 9001
mother 32 534
Note that this makes TWO ssh connections to each server to collect each datum. If you'd like to do this a little more efficiently, you can bundle the information into a single, slightly more complex collection script:
#!/usr/local/bin/bash
servers=(wopr gerty mother)
fmt="%s\t%s\t%s\n"
printf "$fmt" "Host" "UIDs" "Highest"
printf "$fmt" "----" "----" "-------"
gather="awk -F: '\$3>n&&\$3<60000{n=\$3} END{print NR,n}' /etc/passwd"
for server in ${servers[#]}; do
read count highest < <(ssh "$server" "$gather")
printf "$fmt" "$server" "$count" "$highest"
done
(Identical results.)
ssh remoteserver.example /bin/bash < localscript.bash
(Note: the "proper" way to authenticate without manually entering in password is to use SSH keys. Storing password in plaintext even in your local scripts is a potential security vulnerability)
You can run expect as part of your bash script. Here's a quick example that you can hack into your existing script:
login=user
IP=127.0.0.1
password='your_password'
expect_sh=$(expect -c "
spawn ssh $login#$IP
expect \"password:\"
send \"$password\r\"
expect \"#\"
send \"./$remote_side_script\r\"
expect \"#\"
send \"cd /lib\r\"
expect \"#\"
send \"cat file_name\r\"
expect \"#\"
send \"exit\r\"
")
echo "$expect_sh"
You can also use pscp to copy files back and forth as part of a script so you don't need to manually supply the password as part of the interaction:
Install putty-tools:
$ sudo apt-get install putty-tools
Using pscp in your script:
pscp -scp -pw $password file_to_copy $login#$IP:$dest_dir
maybe you'd like to try the expect command as following
#!/usr/bin/expect
set timeout 30
spawn ssh -p ssh_port -l ssh_username ssh_server_host
expect "password:"
send "your_passwd\r"
interact
the expect command will catch the "password:" and then auto fill the passwd your send by above.
Remember that replace the ssh_port, ssh_username, ssh_server_host and your_passwd with your own configure
Related
I'm trying to test ssh trust between a linux box against 12 other linux boxes using a shell script and I'm trying to pass user input as 'yes' for the question below automatically.
Are you sure you want to continue connecting (yes/no)?
but the script is failing with error 'Host key verification failed'. I manually executed the ssh command with << EOT on one of the server but the I still get user prompt question. Is there any-other way to pass input value for user prompts automatically while running ssh command?
Note: I cannot use spawn or except do you some system limitation and I cannot install them due to organisations access restrictions.
I tried with the following options but none of them worked for me
[command] << [EOT, EOL, EOF]
echo 'yes'
[EOT, EOL, EOF]
yes | ./script.sh
printf "yes" | ./script.sh
echo "yes" | ./script.sh
./script.sh 'read -p "Are you sure you want to continue connecting (yes/no)?";echo "yes"'
sh```
for server in `cat server_list` ; do
UPPER_MACHINE_NAME=`echo $server | cut -d '.' -f 1`
UPPER_MACHINE_NAME=${UPPER_MACHINE_NAME^^}
ssh -tt user#$UPPER_MACHINE_NAME << EOT
echo 'yes'
touch /usr/Finastra/sshtest.txt
EOT
done
```
I want to change root password of multiple server's. I used shell with for loop and chpasswd utility to do this. Since the sudo account is password enabled, it is prompting sudo password all the time I exit script.
Below is bash Script is written in bash. But always prompting for password.
#!/bin/bash
pass="PASSWORD"
for i in $(cat serverlist)
do
ssh -t sudouser#$i "sudo chpasswd <<EOF
root:"$pass"
EOF" ;
done
Completely automated bash to change root password.
I also think you should use expect. The script I've written isn't fully tested, since I don't have a server which I'm conformable on to change passwords :-)
#!/bin/bash
read -p "Server username? " USERNAME
read -sp "Server password for ${USERNAME}? " PASSWORD
echo
read -p "Name of file containing server list? " S_FILE
read -p "User to change on servers? " S_USERNAME
read -sp "New password for user ${S_USERNAME}?" S_PASSWORD
echo
while IFS= read -r SERVER; do
[ ! -z "${SERVER}" ] || continue
expect <<-EOF
spawn ssh ${USERNAME}#${SERVER}
expect "*: " { send "${PASSWORD}\r" }
expect "*$ " { send "echo '${S_USERNAME}:${S_PASSWORD}' | sudo chpasswd\r" }
expect "*: " { send "${PASSWORD}\r" }
expect "*$ " { send "exit\r" }
EOF
echo
done < ${S_FILE}
exit $?
Writing a script to do unattended root things is dangerous. All you need is one machine to somehow behave differently than you expect and your automated approach wouldn't work. Worse, you could end up in some bad state, possibly without even realizing that anything went wrong.
This sounds like a great fit for csshx (or something similar). Use it to manually apply whatever changes you want in parallel across multiple hosts. For example, you could connect to 16 hosts at once like this:
csshx host[1-16]
then type commands and watch output for each host.
If this seems infeasible due to the number of machines you have, I would counter that it's much safer than scripting, and - even if "slow" - the overall time spent might very well be less than that of trying to create an automated solution. ;)
So here is my problem, I have this script I wrote where I'm exporting two variables however they're not making it into the subshell.
The point of this script is to change a users password and clear out their pam_tally for CentOS and Ubuntu hosts.
A little background is that this environment's users are managed by puppet but the passwords are all local, ssh keys are not allowed either (this is set in stone and can't be changed so I have to work with what I got) and the reason is that every log in has to be manual (even number of sessions are limited to two so you can't even user csshX effectively).
Here is my script
#!/bin/bash
echo "Please enter user whose password you want to change"
read NEWUSER
echo "Please enter new password for user"
read -s -p "Temp Password:" TEMPPASSWORD
PASSWORD=$TEMPPASSWORD
export PASSWORD
NEWUSER2=$NEWUSER
export NEWUSER2
for i in HOST{cluster1,cluster2,cluster3}0{1..9}
do
ping -c 2 $i && (echo $i ; ssh -t $i '
sudo pam_tally2 --user=$NEWUSER2 --reset
echo -e "$PASSWORD\n$PASSWORD" | sudo passwd $NEWUSER2
sudo chage -d 0 $NEWUSER2
')
done
You are using ssh to connect to a remote host and run a script on that host. ssh does not export the local environment to the remote session but instead performs a login on the remote host which sets the environment according to the remote user's configuration on the remote host.
I suggest you pass all needed values via the command you want to execute. This could be done like this:
ssh -t $i '
sudo pam_tally2 --user='"$NEWUSER2"' --reset
echo -e "'"$PASSWORD"'\n'"$PASSWORD"'" | sudo passwd '"$NEWUSER2"'
sudo chage -d 0 '"$NEWUSER2"
Watch closely how this uses quotes. At each occasion where you used a variable, I terminate the single-quoted string (using '), then add a double-quoted use of the variable (e. g. "$PASSWORD") and then start the single-quoted string again (using ' again). This way, the shell executing the ssh command will expand the variables already, so you have no need to pass them into the remote shell.
But be aware that special characters in the password (like " or ' or or maybe a bunch of other characters) can mean trouble using this simple mechanism. To be safe against this as well, you would need to use the %q format specifier of the printf command to quote your values before passing them:
ssh -t "$i" "$(printf '
sudo pam_tally2 --user=%q --reset
{ echo %q; echo %q; } | sudo passwd %q
sudo chage -d 0 %q' \
"$NEWUSER2" "$PASSWORD" "$PASSWORD" "$NEWUSER2" "$NEWUSER2")"
I am having some issues trying to connect through telnet to a mail server.The main problem that I am having is that I need to create a script that logs me to the destination and I can't find a way to echo the password.
What I tried:
telnet host -l username ; echo 'password'
And still it asks for my password.Is there any way to fix this or I am doing something wrong?
First of all, you can use eval:
eval "{ echo user_name; sleep 1; echo pass; sleep 1; echo '?'; sleep 5; }" | telnet host_address
Make sure to replace user_name, pass, ? which is the command you want to run and host_address where your telnet host is listening; for me it is a local IP.
It’s surprisingly easy to script a set of command and pipe them into the telnet application. All you need to do is something like this:
(echo commandname;echo anothercommand) | telnet host_address
The only problem is the nagging login that you have to get through… it doesn’t show up right away. So if you pipe in an “echo admin” and then “echo password,” it will happen too quickly and won’t be sent to the server. The solution? Use the sleep command!
Adding in a couple of sleep 3 commands, to wait three seconds, solves the problem. First we’ll echo the username and password, and then we’ll echo the reboot command, and each time we’ll wait three seconds between. The final command will reboot the server immediately:
(sleep 3;echo admin;sleep 3;echo mypassword;sleep 3;echo system reboot;sleep 3;) | telnet host_address
You can put this into a shell script and run it whenever you want. Or you can add it to your cron like this (on OS X or Linux):
crontab -e
Add this line somewhere:
1 7 * * * (sleep 3;echo admin;sleep 3;echo mypassword;sleep 3;echo system reboot;sleep 3;) | telnet host_address
This will reboot your router at 7:01 AM each morning.
AFAIK, you won't be able to automate telnet that way. But it is still possible - even if it is a very bad idea (I'll elaborate on that later).
First why does your try fail :
you launched a telnet command reading from stdin (I suppose terminal) and writing to stdout and stderr (I suppose also a terminal)
if your telnet is reasonably recent, it tries to protect your authentication and asks your password from /dev/tty (for security reasons)
when that command has ended you write password on your own terminal
What should you do instead :
launch telnet with automatic authentication disable (on mine it is telnet -X SRA)
feed its input with the commands you want to pass
wait some delay before entering input, at least for login and password, because if you don't telnet clear input before reading and discards your inputs
Here is an example that allowed me to telnet to my own machine :
sh << EOF | telnet -X SRA localhost
sleep 2
echo my_user_name
sleep 1
echo my_password
# sleep 1 # looks like it can be removed
echo echo foo and bar
sleep 1
EOF
It correctly logs me into my box, executes echo foo and bar (essential command :-) ) and disconnects
Now why you should never do that :
you write a password in clear text in a script file which is poor security practice
you use telnet to do batch processing when it is not intended to be used that way : the script may not be portable to another telnet version
If you really want to pass command in a batch way to a remote server, you should instead try to use ssh which :
has options to process authentication securely (no password in script, nothing in clear text)
is intended to be used in batch mode as well as interactively
If you cannot use ssh (some sysadmin do not like to have uncontrolled input ssh connections) you could also try to use rsh. It is older, far less secure, but at least was designed for batch usage.
Thanks to Harvix answer, I got knew that there is also expect alternative native for shell, called sexpect. Get it from here. Then create this script (I call it telnetpass):
#!/bin/bash
# This script is used for automatically pass authentication by username and password in telnet prompt
# Its goal is similar as sshpass, but for telnet, so I call it telnetpass
. ~/.private/cisco_pw # should contain PASSWORD variable
export SEXPECT_SOCKFILE=/tmp/sexpect-telnetpass-$$.sock
sexpect spawn telnet $1
sexpect expect -cstring 'Username:'
sexpect send -enter $USER
sexpect expect -cstring 'Password:'
sexpect send -enter $PASSWORD
sexpect interact
Then you can run: telnetpass Host125 and got pass the authentication automatically
Trying 198.51.100.78 ...
Connected to Host125.
Escape character is '^]'.
User Access Verification
Username: ashark
Password:
host-125>
I like this solution more than using sleep commands as suggested in another answers, because sleep solutions sometimes fail.
Have you tried using the expect command ?? You will have to create a script where you identify the 'expected' response from the server e.g. 'Password:' and then supply the password in the script. The following will explain: https://en.wikipedia.org/wiki/Expect - A good example is also shown here: http://en.kioskea.net/faq/4736-shell-script-for-telnet-and-run-commands
Try eval:
eval "{ echo;
sleep 3;
echo $user;
sleep 1;
echo $pass;
sleep 1;
echo '?';
sleep 1; }" | telnet your_host
In this example, my remote command is '?' (help).
The sleeps (maybe not all of them nor these times; trial-error...) are needed to avoid telnet misses some inputs.
The user and password are passed as variables ($user and $pass). Take into account security recommendations to store the password if you are scripting.
I am working on automating some telnet related tasks, using Bash scripts.
Once automated, there will be no interaction of the user with telnet (that is, the script will be totally automated).
The scripts looks something like this:
# execute some commands on the local system
# access a remote system with an IP address: 10.1.1.1 (for example)
telnet 10.1.1.1
# execute some commands on the remote system
# log all the activity (in a file) on the local system
# exit telnet
# continue with executing the rest of the script
There are two problems I am facing here:
How to execute the commands on the remote system from the script (without human interaction)?
From my experience with some test code, I was able to deduce that when telnet 10.1.1.1 is executed, telnet goes into an interactive session and the subsequent lines of code in the script are executed on the local system. How can I run the lines of code on the remote system rather than on the local one?
I am unable to get a log file for the activity in the telnet session on the local system. The stdout redirect I used makes a copy on the remote system (I do not want to perform a copy operation to copy the log to the local system). How can I achieve this functionality?
While I'd suggest using expect, too, for non-interactive use the normal shell commands might suffice. telnet accepts its command on stdin, so you just need to pipe or write the commands into it through heredoc:
telnet 10.1.1.1 <<EOF
remotecommand 1
remotecommand 2
EOF
(Edit: Judging from the comments, the remote command needs some time to process the inputs or the early SIGHUP is not taken gracefully by telnet. In these cases, you might try a short sleep on the input:)
{ echo "remotecommand 1"; echo "remotecommand 2"; sleep 1; } | telnet 10.1.1.1
In any case, if it's getting interactive or anything, use expect.
Write an expect script.
Here is an example:
#!/usr/bin/expect
#If it all goes pear shaped the script will timeout after 20 seconds.
set timeout 20
#First argument is assigned to the variable name
set name [lindex $argv 0]
#Second argument is assigned to the variable user
set user [lindex $argv 1]
#Third argument is assigned to the variable password
set password [lindex $argv 2]
#This spawns the telnet program and connects it to the variable name
spawn telnet $name
#The script expects login
expect "login:"
#The script sends the user variable
send "$user "
#The script expects Password
expect "Password:"
#The script sends the password variable
send "$password "
#This hands control of the keyboard over to you (Nice expect feature!)
interact
To run:
./myscript.expect name user password
Telnet is often used when you learn the HTTP protocol. I used to use that script as a part of my web scraper:
echo "open www.example.com 80"
sleep 2
echo "GET /index.html HTTP/1.1"
echo "Host: www.example.com"
echo
echo
sleep 2
Let's say the name of the script is get-page.sh, then this will give you an HTML document:
get-page.sh | telnet
I hope this will be helpful to someone ;)
This worked for me..
I was trying to automate multiple telnet logins which require a username and password. The telnet session needs to run in the background indefinitely since I am saving logs from different servers to my machine.
telnet.sh automates telnet login using the 'expect' command. More info can be found here: http://osix.net/modules/article/?id=30
telnet.sh
#!/usr/bin/expect
set timeout 20
set hostName [lindex $argv 0]
set userName [lindex $argv 1]
set password [lindex $argv 2]
spawn telnet $hostName
expect "User Access Verification"
expect "Username:"
send "$userName\r"
expect "Password:"
send "$password\r";
interact
sample_script.sh is used to create a background process for each of the telnet sessions by running telnet.sh. More information can be found in the comments section of the code.
sample_script.sh
#!/bin/bash
#start screen in detached mode with session-name 'default_session'
screen -dmS default_session -t screen_name
#save the generated logs in a log file 'abc.log'
screen -S default_session -p screen_name -X stuff "script -f /tmp/abc.log $(printf \\r)"
#start the telnet session and generate logs
screen -S default_session -p screen_name -X stuff "expect telnet.sh hostname username password $(printf \\r)"
Make sure there is no screen running in the backgroud by using the
command 'screen -ls'.
Read
http://www.gnu.org/software/screen/manual/screen.html#Stuff to read
more about screen and its options.
'-p' option in sample_script.sh
preselects and reattaches to a specific window to send a command via
the ‘-X’ option otherwise you get a 'No screen session found' error.
You can use expect scripts instaed of bash.
Below example show how to telnex into an embedded board having no password
#!/usr/bin/expect
set ip "<ip>"
spawn "/bin/bash"
send "telnet $ip\r"
expect "'^]'."
send "\r"
expect "#"
sleep 2
send "ls\r"
expect "#"
sleep 2
send -- "^]\r"
expect "telnet>"
send "quit\r"
expect eof
The answer by #thiton was helpful but I wanted to avoid the sleep command. Also telnet didn't exit the interactive mode, so my script got stuck.
I solved that by sending telnet command with curl (which seems to wait for the response) and by explicitly telling telnet to quit like this:
curl telnet://10.1.1.1:23 <<EOF
remotecommand 1
remotecommand 2
quit
EOF
Following is working for me...
put all of your IPs you want to telnet in IP_sheet.txt
while true
read a
do
{
sleep 3
echo df -kh
sleep 3
echo exit
} | telnet $a
done<IP_sheet.txt
#!/bin/bash
ping_count="4"
avg_max_limit="1500"
router="sagemcom-fast-2804-v2"
adress="192.168.1.1"
user="admin"
pass="admin"
VAR=$(
expect -c "
set timeout 3
spawn telnet "$adress"
expect \"Login:\"
send \"$user\n\"
expect \"Password:\"
send \"$pass\n\"
expect \"commands.\"
send \"ping ya.ru -c $ping_count\n\"
set timeout 9
expect \"transmitted\"
send \"exit\"
")
count_ping=$(echo "$VAR" | grep packets | cut -c 1)
avg_ms=$(echo "$VAR" | grep round-trip | cut -d '/' -f 4 | cut -d '.' -f 1)
echo "1_____ping___$count_ping|||____$avg_ms"
echo "$VAR"
Use ssh for that purpose. Generate keys without using a password and place it to .authorized_keys at the remote machine. Create the script to be run remotely, copy it to the other machine and then just run it remotely using ssh.
I used this approach many times with a big success. Also note that it is much more secure than telnet.
Here is how to use telnet in bash shell/expect
#!/usr/bin/expect
# just do a chmod 755 one the script
# ./YOUR_SCRIPT_NAME.sh $YOUHOST $PORT
# if you get "Escape character is '^]'" as the output it means got connected otherwise it has failed
set ip [lindex $argv 0]
set port [lindex $argv 1]
set timeout 5
spawn telnet $ip $port
expect "'^]'."
Script for obtain version of CISCO-servers:
#!/bin/sh
servers='
192.168.34.1
192.168.34.3
192.168.34.2
192.168.34.3
'
user='cisco_login'
pass='cisco_password'
show_version() {
host=$1
expect << EOF
set timeout 20
set host $host
set user $user
set pass $pass
spawn telnet $host
expect "Username:"
send "$user\r"
expect "Password:"
send "$pass\r"
expect -re ".*#"
send "show version\r"
expect -re ".*-More-.*"
send " "
expect -re ".*#"
send "exit\r"
EOF
}
for ip in $servers; do
echo '---------------------------------------------'
echo "$ip"
show_version $ip | grep -A3 'SW Version'
done
Here is a solution that will work with a list of extenders. This only requires bash - some of the answers above require expect and you may not be able to count on expect being installed.
#!/bin/bash
declare -a Extenders=("192.168.1.48" "192.168.1.50" "192.168.1.51")
# "192.168.1.52" "192.168.1.56" "192.168.1.58" "192.168.1.59" "192.168.1.143")
sleep 5
# Iterate the string array using for loop
for val in ${Extenders[#]}; do
{ sleep 0.2; echo "root"; sleep 0.2; echo "ls"; sleep 0.2; } | telnet $val
done
Play with tcpdump or wireshark and see what commands are sent to the server itself
Try this
printf (printf "$username\r\n$password\r\nwhoami\r\nexit\r\n") | ncat $target 23
Some servers require a delay with the password as it does not hold lines on the stack
printf (printf "$username\r\n";sleep 1;printf "$password\r\nwhoami\r\nexit\r\n") | ncat $target 23**