I'm trying to write a shell script for remote login that doesn't ask for a password. Here's what I've tried and when I execute it, it still does ask for a password. Here's the code :
#!/usr/bin/expect -f
spawn ssh ronnie-pc
expect "Password:"
send "password\r"
interact
I'm not sure if this is the right way to do it and it takes a lot of time to login.
why use shell? use pythons pexpect which works everywhere and easy to use.
Related
I want to run some commands on another machine after I logged in through ssh. I have automated login using expect. I don't know much about bash and expect. Please help me out.
Here is what i have written:
spawn ssh user#ip
expect "password:" { send "mypassword\n"}
interact
echo yes
If you just want to execute a single command on the remote server, you can send the command in single quotes like: ssh user#ip 'echo "yes"'
But if you want multiple commands to be run, then its better to use telnet than ssh.
I'm trying to write a simple shell script to execute commands on my server box via ssh.
I'm not trying to pass a password within the shell script, I'm just wondering how I can get it to run commands on that box after the password is entered.
So far, when I execute my script, nothing happens after I enter the password. Or, it executes when I kill the ssh process.
I'm sure it's really easy, but I've been searching for hours and nothing has come up on the net, probably because nobody else needs to ask that.
Is there some way to do this natively within the shell? Thanks!
Look if you want to ssh without prompting password then you need a key authentication rather password authentication.
Else try;
sudo apt-get install sshpass
sshpass -p your_password ssh user#hostname
And to execute command at remote;
ssh user#host 'command'
I am working on making a website for a class that you log into with a username and password, and then it takes you to a page that shows your grades in the class.
The website is being run with a bash script, and will be hosted on a machine where the users already have a username and password to login.
I also have a script called calcgrade.sh that will calculate the grades for either the user who is currently logged in, or the user passed to the script as an argument.
So originally, I was going to use this command:
echo -e "$password\n" | sudo -Sk -u $user ./website/calcgrade.sh
to run calcgrade.sh as the user of the website. However, I found out that sudo asks for the password of the user who is currently logged in, not the target user you are trying to run a command as.
So after some reading, I found a better option would be to use su with an expect script, but I can't get it to work. Here is the code for the expect script (currently username and password are hard coded in for testing):
#!/usr/bin/expect
log_user 0
spawn /bin/su myusername
expect "Password: "
send "mypassword"
spawn "./website/calcgrade.sh"
interact
When I run this script, it doesn't seem to log in the user with su, as it goes on to run calcgrade.sh with my account, rather than the user's.
Do you see what is wrong with my script? Or can you see a better way to do what I want?
Also, another problem with this method is that calcgrade.sh is supposed to send some output to stderr, but when I run it with the expect script, the error messages get sent to the website (the server works by sending the html for the website to stdout). Is there a way around this, or might it be better to have the expect script just check with su if username/password is correct, and then if so, then run ./calcgrade.sh $user afterwards?
First of all, here's the correct way to do what you want to do:
Give your web server user sudo permissions to run ./website/calcgrade.sh as any user, without requiring a password.
Have the web server authenticate the user however you see fit.
Have it run sudo -u someuser ./website/calcgrade.sh, no password required.
Now let's look at why your approach didn't work:
It's commonly believed that su switches user. This is not the case. It actually starts a new shell running as another user.
This means that you can't spawn su otheruser, let it finish, and then afterwards spawn calcgrade.sh.
Instead you have to run su otheruser, and then send commands to the shell that su starts:
#!/usr/bin/expect
log_user 0
spawn /bin/su someuser
expect "Password: "
send "somepassword\n"
# Now wait for a prompt and send the command to run
expect "$"
send "./website/calcgrade.sh\n"
interact
I'm trying to write a shell script (Bash) to log into a SonicWall firewall device and issue a command to perform automated backups of the devices ruleset. I prefer to do this in Bash but I will accept a python, perl, except, or applescript solution. If it cannot be done in bash please mention that.
Problems:
1.) SSH server on firewall is custom, a user name and password has to be specified after issuing a
$ ssh server.com
so no matter what username you issue e.g.
$ ssh admin#server.com
the SSH server still presents a username and password box after
2.) The SSH server is minimal and I cannot use public-keys
I tried using a here-document but it isn't working and it results in an immediate "connection closed by remote host".
The command I need to execute takes the form of this:
export preferences ftp "ftp.server.com" "user1" "mypassword" "output.exp"
Connecting gives me this:
$ ssh admin#server.com
Copyright (c) 2010 SonicWALL, Inc.
User:
After a username is issued it brings up the password prompt:
User:user1
Password:
I tried a here-document to no avail.
$ ssh server <<+
user1
mypassword
export preferences ftp "ftp.server.com" "user1" "mypassword" "output.exp"
exit
+
Pseudo-terminal will not be allocated because stdin is not a terminal.
Connection to 10.1.1.1 closed by remote host.
I tried using echo to pipe in commands too but that doesn't work either.
Typing the commands in manually works just fine.
Any help on this would be greatly appreciated.
As others have suggested, expect is probably what you want to use here.
Here's a short example of how to work with it from bash to get you started:
login=root
IP=127.0.01
password=helloworld
# +whatever variables you need to use
# Run the expect script from bash
expect_sh=$(expect -c "
spawn ssh $login#$IP
expect \"password:\"
send \"$password\r\"
expect \"#\"
send \"cd $dest_dir\r\"
expect \"#\"
send \"chmod +x $server_side_script $other_script\r\"
expect \"#\"
send \"./$device_side_script\r\"
expect \"#\"
send \"cat results_file\r\"
expect \"#\"
send \"exit\r\"
")
# Output or do something with the results
echo "$expect_sh"
You can automate the ssh session using the original expect, here is a nice article discussing it in detail: http://solar1.net/drupal/automating%20SSH%20with%20expect or the Python module pexepect: http://linux.byexamples.com/archives/346/python-how-to-access-ssh-with-pexpect/
I'm not a BASH expert but i had to do something where interactive password prompts was causing me a problem.
Basically your script needs to wait to be asked to enter login credentials, and pass them when prompted in order to login, once logged in you can issue the command.
I recommend looking at spawning "expect" sessions. Basically in your script you use expect to basically say "i expect to see password: in the response, when i do, i need to pass in the following data".
Here's the wiki page which helps explain it http://en.wikipedia.org/wiki/Expect
and if you google around you will find lots of help.
that didn't work for me.
I had to pass the variables to the script at launch.
Example launch script login2.sh, with three arguments:
-bash-4.1$ ./login2.sh Jan2**** HIE_SUPER 10.244.112.182
I realize this question has been asked a few times but I could not find a relevant answer anywhere in my searching.
I am working in a development environment where security is not an issue and anyone could just guess the password if the thought for a few seconds.
What I am trying to do is simple. I have created an alias function in my local .bashrc file and I would like this function to automatically log into a machine with a default password.
My current implementation looks something like this:
function s () {
ssh root#192.168.1.$1
}
When I run it I get something like this:
~]s 122
ssh root#192.168.1.122
root#192.168.1.122's password:
Using Bash, and not using RSA keys I would like to get this to use the default password 'password'.
I've tried the following where IP and User have already been set.
Do=$(expect -c "
spawn ssh $User#${IP[0]}.${IP[1]}.${IP[2]}.${IP[3]}
expect \"yes/no\"
send \"yes\r\"
expect \"assword\" send \"password\"")
echo $Do
$Do
It gives the follwing error:
Connecting and logging into server using expect
usage: send [args] string
while executing
"send"
invoked from within
"expect "assword" send "password""
Administrator#192.168.1.176's password:
bash: spawn: command not found...
Using the following command I am able to connect a machine. If I remove the interact it just runs the uptime command and closes the connection. With the interact command I am unable to see what I am typing or actually interact with the machine. Any ideas?
Do=$(expect -c "spawn ssh $User#${IP[0]}.${IP[1]}.${IP[2]}.${IP[3]}; set timeout 4; expect \"assword\"; send \"password\n\"; expect \"test\"; send \"uptime\n\"; interact;");echo $Do;
You can do this with the expect tool: http://expect.sourceforge.net/
It's widely available, so depending on your system, the equivalent of sudo apt-get install expect or yum install expect will install it.
Here's an example of an expect script with ssh. This logs you in and gives you control of the interactive prompt:
#!/usr/bin/expect
set login "root"
set addr "127.0.0.1"
set pw "password"
spawn ssh $login#$addr
expect "$login#$addr\'s password:"
send "$pw\r"
expect "#"
send "cd /developer\r"
interact
Here's an example of how to use expect as part of a bash script. This logs in with ssh, cd to /var, runs a script, then exits the ssh session.
#!/bin/bash
...
login_via_ssh_and_do_stuff() {
# build the expect script in bash
expect_sh=$(expect -c "
spawn ssh root#127.0.0.1
expect \"password:\"
send \"password\r\"
expect \"#\"
send \"cd /var\r\"
expect \"#\"
send \"chmod +x my_script.sh\r\"
expect \"#\"
send \"./my_script.sh\r\"
expect \"#\"
send \"exit\r\"
")
# run the expect script
echo "$expect_sh"
}
You can leave these snippets in a script on your local system, and then just alias to the scripts.
Also: I know you said security isn't an issue, but I'd like to just note, again, that the "proper" way to ssh without using a password is to use a ssh key-pair =)
Use sshpass which is available in package repositories on major Linux-es.
For example, when password is in password.txt file:
sshpass -fpassword.txt ssh username#hostname
sshpass runs ssh in a dedicated tty, fooling it into thinking it is
getting the password from an interactive user.