how to write a bash shell script to ssh to remote machine and change user and export a env variable and do other commands - linux

I have a webservice that runs on multiple different remote redhat machines. Whenever I want to update the service I will sync down the new webservice source code written in perl from a version control depot(I use perforce) and restart the service using that new synced down perl code. I think it is too boring to log to remote machines one by one and do that series of commands to restart the service one by one manully. So I wrote a bash script update.sh like below in order to "do it one time one place, update all machines". I will run this shell script in my local machine. But it seems that it won't work. It only execute the first command "sudo -u webservice_username -i" as I can tell from the command line in my local machine. (The code below only shows how it will update one of the remote webservice. The "export P4USER=myname" is for usage of perforce client)
#!/bin/sh
ssh myname#remotehost1 'sudo -u webservice_username -i ; export P4USER=myname; cd dir ; p4 sync ; cd bin ; ./prog --domain=config_file restart ; tail -f ../logs/service.log'
Why I know the only first command is executed? Well because after I input the password for the ssh on my local machine, it shows:
Your environment has been modified. Please check /tmp/webservice.env.
And it just gets stuck there. I mean no return.
As suggested by a commentor, I added "-t" for ssh
#!/bin/sh
ssh -t myname#remotehost1 'sudo -u webservice_username -i ; export P4USER=myname; cd dir ; p4 sync ; cd bin ; ./prog --domain=config_file restart ; tail -f ../logs/service.log'
This would let the local commandline return. But it seems weird, it cannot cd to that "dir", it says "cd:dir: No such file or directory" it also says "p4: command not found". So it looks like the sudo -u command executes with no effect and the export command has either not executed or excuted with no effect.
A detailed local log file is like below:
Your environment has been modified. Please check /tmp/dir/.env.
bash: line 0: cd: dir: No such file or directory
bash: p4: command not found
bash: line 0: cd: bin: No such file or directory
bash: ./prog: No such file or directory
tail: cannot open `../logs/service.log' for reading: No such file or directory
tail: no files remaining

Instead of connecting via ssh and then immediately changing users, can you not use something like ssh -t webservice_username#remotehost1 to connect with the desired username to begin with? That would avoid needing to sudo altogether.
If that isn't a possibility, try wrapping up all of the commands that you want to run in a shell script and store it on the remote machine. If you can get your task working from a script, then your ssh call becomes much simpler and should encounter fewer problems:
ssh myname#remotehost1 '/path/to/script'
For easily updating this script, you can write a short script for your local machine that uploads the most recent version via scp and then uses ssh to invoke it.

Note that when you run:
#!/bin/sh
ssh myname#remotehost1 'sudo -u webservice_username -i ; export P4USER=myname; cd dir ; p4 sync ; cd bin ; ./prog --domain=config_file restart ; tail -f ../logs/service.log'
Your ssh session runs sudo -u webservice_username -i waits for it to exit and then runs the rest of the commands; it does not execute sudo and then run the commands following. This has to do with the context in which you're running the series of commands. All the commands get executed in the shell of myname#remotehost1 and all sudo -u webservice_username - i is starts a shell for webservice_username and doesn't actually run any commands.
Really the best solution here is like bta said; write a script and then rsync/scp it to the destination and then run that using sudo.

export command simply not working with ssh like this, what you want to do is remote modify ~/.bashrc and it will source itself each time u do ssh login.

Related

Running bash script over SSH [duplicate]

I have to run a local shell script (windows/Linux) on a remote machine.
I have SSH configured on both machine A and B. My script is on machine A which will run some of my code on a remote machine, machine B.
The local and remote computers can be either Windows or Unix based system.
Is there a way to run do this using plink/ssh?
If Machine A is a Windows box, you can use Plink (part of PuTTY) with the -m parameter, and it will execute the local script on the remote server.
plink root#MachineB -m local_script.sh
If Machine A is a Unix-based system, you can use:
ssh root#MachineB 'bash -s' < local_script.sh
You shouldn't have to copy the script to the remote server to run it.
This is an old question, and Jason's answer works fine, but I would like to add this:
ssh user#host <<'ENDSSH'
#commands to run on remote host
ENDSSH
This can also be used with su and commands which require user input. (note the ' escaped heredoc)
Since this answer keeps getting bits of traffic, I would add even more info to this wonderful use of heredoc:
You can nest commands with this syntax, and that's the only way nesting seems to work (in a sane way)
ssh user#host <<'ENDSSH'
#commands to run on remote host
ssh user#host2 <<'END2'
# Another bunch of commands on another host
wall <<'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
You can actually have a conversation with some services like telnet, ftp, etc. But remember that heredoc just sends the stdin as text, it doesn't wait for response between lines
I just found out that you can indent the insides with tabs if you use <<-END!
ssh user#host <<-'ENDSSH'
#commands to run on remote host
ssh user#host2 <<-'END2'
# Another bunch of commands on another host
wall <<-'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<-'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
(I think this should work)
Also see
http://tldp.org/LDP/abs/html/here-docs.html
Also, don't forget to escape variables if you want to pick them up from the destination host.
This has caught me out in the past.
For example:
user#host> ssh user2#host2 "echo \$HOME"
prints out /home/user2
while
user#host> ssh user2#host2 "echo $HOME"
prints out /home/user
Another example:
user#host> ssh user2#host2 "echo hello world | awk '{print \$1}'"
prints out "hello" correctly.
This is an extension to YarekT's answer to combine inline remote commands with passing ENV variables from the local machine to the remote host so you can parameterize your scripts on the remote side:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'
# commands to run on remote host
echo $ARG1 $ARG2
ENDSSH
I found this exceptionally helpful by keeping it all in one script so it's very readable and maintainable.
Why this works. ssh supports the following syntax:
ssh user#host remote_command
In bash we can specify environment variables to define prior to running a command on a single line like so:
ENV_VAR_1='value1' ENV_VAR_2='value2' bash -c 'echo $ENV_VAR_1 $ENV_VAR_2'
That makes it easy to define variables prior to running a command. In this case echo is our command we're running. Everything before echo defines environment variables.
So we combine those two features and YarekT's answer to get:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'...
In this case we are setting ARG1 and ARG2 to local values. Sending everything after user#host as the remote_command. When the remote machine executes the command ARG1 and ARG2 are set the local values, thanks to local command line evaluation, which defines environment variables on the remote server, then executes the bash -s command using those variables. Voila.
<hostA_shell_prompt>$ ssh user#hostB "ls -la"
That will prompt you for password, unless you have copied your hostA user's public key to the authorized_keys file on the home of user .ssh's directory. That will allow for passwordless authentication (if accepted as an auth method on the ssh server's configuration)
I've started using Fabric for more sophisticated operations. Fabric requires Python and a couple of other dependencies, but only on the client machine. The server need only be a ssh server. I find this tool to be much more powerful than shell scripts handed off to SSH, and well worth the trouble of getting set up (particularly if you enjoy programming in Python). Fabric handles running scripts on multiple hosts (or hosts of certain roles), helps facilitate idempotent operations (such as adding a line to a config script, but not if it's already there), and allows construction of more complex logic (such as the Python language can provide).
cat ./script.sh | ssh <user>#<host>
chmod +x script.sh
ssh -i key-file root#111.222.3.444 < ./script.sh
Try running ssh user#remote sh ./script.unx.
Assuming you mean you want to do this automatically from a "local" machine, without manually logging into the "remote" machine, you should look into a TCL extension known as Expect, it is designed precisely for this sort of situation. I've also provided a link to a script for logging-in/interacting via SSH.
https://www.nist.gov/services-resources/software/expect
http://bash.cyberciti.biz/security/expect-ssh-login-script/
ssh user#hostname ". ~/.bashrc;/cd path-to-file/;. filename.sh"
highly recommended to source the environment file(.bashrc/.bashprofile/.profile). before running something in remote host because target and source hosts environment variables may be deffer.
I use this one to run a shell script on a remote machine (tested on /bin/bash):
ssh deploy#host . /home/deploy/path/to/script.sh
if you wanna execute command like this
temp=`ls -a`
echo $temp
command in `` will cause errors.
below command will solve this problem
ssh user#host '''
temp=`ls -a`
echo $temp
'''
If the script is short and is meant to be embedded inside your script and you are running under bash shell and also bash shell is available on the remote side, you may use declare to transfer local context to remote. Define variables and functions containing the state that will be transferred to the remote. Define a function that will be executed on the remote side. Then inside a here document read by bash -s you can use declare -p to transfer the variable values and use declare -f to transfer function definitions to the remote.
Because declare takes care of the quoting and will be parsed by the remote bash, the variables are properly quoted and functions are properly transferred. You may just write the script locally, usually I do one long function with the work I need to do on the remote side. The context has to be hand-picked, but the following method is "good enough" for any short scripts and is safe - should properly handle all corner cases.
somevar="spaces or other special characters"
somevar2="!##$%^"
another_func() {
mkdir -p "$1"
}
work() {
another_func "$somevar"
touch "$somevar"/"$somevar2"
}
ssh user#server 'bash -s' <<EOT
$(declare -p somevar somevar2) # transfer variables values
$(declare -f work another_func) # transfer function definitions
work # call the function
EOT
The answer here (https://stackoverflow.com/a/2732991/4752883) works great if
you're trying to run a script on a remote linux machine using plink or ssh.
It will work if the script has multiple lines on linux.
**However, if you are trying to run a batch script located on a local
linux/windows machine and your remote machine is Windows, and it consists
of multiple lines using **
plink root#MachineB -m local_script.bat
wont work.
Only the first line of the script will be executed. This is probably a
limitation of plink.
Solution 1:
To run a multiline batch script (especially if it's relatively simple,
consisting of a few lines):
If your original batch script is as follows
cd C:\Users\ipython_user\Desktop
python filename.py
you can combine the lines together using the "&&" separator as follows in your
local_script.bat file:
https://stackoverflow.com/a/8055390/4752883:
cd C:\Users\ipython_user\Desktop && python filename.py
After this change, you can then run the script as pointed out here by
#JasonR.Coombs: https://stackoverflow.com/a/2732991/4752883 with:
`plink root#MachineB -m local_script.bat`
Solution 2:
If your batch script is relatively complicated, it may be better to use a batch
script which encapsulates the plink command as well as follows as pointed out
here by #Martin https://stackoverflow.com/a/32196999/4752883:
rem Open tunnel in the background
start plink.exe -ssh [username]#[hostname] -L 3307:127.0.0.1:3306 -i "[SSH
key]" -N
rem Wait a second to let Plink establish the tunnel
timeout /t 1
rem Run the task using the tunnel
"C:\Program Files\R\R-3.2.1\bin\x64\R.exe" CMD BATCH qidash.R
rem Kill the tunnel
taskkill /im plink.exe
This bash script does ssh into a target remote machine, and run some command in the remote machine, do not forget to install expect before running it (on mac brew install expect )
#!/usr/bin/expect
set username "enterusenamehere"
set password "enterpasswordhere"
set hosts "enteripaddressofhosthere"
spawn ssh $username#$hosts
expect "$username#$hosts's password:"
send -- "$password\n"
expect "$"
send -- "somecommand on target remote machine here\n"
sleep 5
expect "$"
send -- "exit\n"
You can use runoverssh:
sudo apt install runoverssh
runoverssh -s localscript.sh user host1 host2 host3...
-s runs a local script remotely
Useful flags:
-g use a global password for all hosts (single password prompt)
-n use SSH instead of sshpass, useful for public-key authentication
If it's one script it's fine with the above solution.
I would set up Ansible to do the Job. It works in the same way (Ansible uses ssh to execute the scripts on the remote machine for both Unix or Windows).
It will be more structured and maintainable.
It is unclear if the local script uses locally set variables, functions, or aliases.
If it does this should work:
myscript.sh:
#!/bin/bash
myalias $myvar
myfunction $myvar
It uses $myvar, myfunction, and myalias. Let us assume they is set locally and not on the remote machine.
Make a bash function that contains the script:
eval "myfun() { `cat myscript.sh`; }"
Set variable, function, and alias:
myvar=works
alias myalias='echo This alias'
myfunction() { echo This function "$#"; }
And "export" myfun, myfunction, myvar, and myalias to server using env_parallel from GNU Parallel:
env_parallel -S server -N0 --nonall myfun ::: dummy
Extending answer from #cglotr. In order to write inline command use printf, it useful for simple command and it support multiline using char escaping '\n'
example :
printf "cd /to/path/your/remote/machine/log \n tail -n 100 Server.log" | ssh <user>#<host> 'bash -s'
See don't forget to add bash -s
There is another approach ,you can copy your script in your host with scp command then execute it easily .
First, copy the script over to Machine B using scp
[user#machineA]$ scp /path/to/script user#machineB:/home/user/path
Then, just run the script
[user#machineA]$ ssh user#machineB "/home/user/path/script"
This will work if you have given executable permission to the script.

calling SSH Sudo Commands in a bash script

I am trying to run the command while looping through
a series of sever addresses.
while read server
do
ssh -t $sever "sudo md5sum $fileName >> hashes"
done < serverNamesFile
within a script in bash but i keep getting this error
sudo: sorry, you must have a tty to run sudo
if I run the same line of commands in the command line though, it works perfectly fine.
Can someone tell me why this keeps happening?
you probably have
Defaults requiretty
in your /etc/sudoers file.
As the option's name suggests, that will cause sudo to require a tty
I solved my problem. apparently looping through a series of servers inside a script causes the "TTY" error for SSH.
a better practice is to create a script that takes in the address of the server you want to SSH in and then pass in the commands that way. you can still loop through a series of file or commands by calling SSH each time and use this command:
while read stuff
do
ssh -qtt $severName " command"
done < $fileStuff

ssh command is showing no such file or directory when executing within shell script

I am trying to run a script in remote machine using ssh.
sshpass -p "" ssh abc#remote.com "bash -s" < path/file.sh
When I execute this command normally, It is executing.
But when i put this into another shell script and executing it then it showing
no such file or directory
I tried putting #!/bin/bash in the top of code also.
But no use. Please can anyone help me?
Actually second time it runs on your local machine not on remote machine try following
ssh abc#remote.com "cd /home && ls -l"

SSH, run process and then ignore the output

I have a command that will SSH and run a script after SSH'ing. The script runs a binary file.
Once the script is done, I can type any key and my local terminal goes back to its normal state. However, since the process is still running in the machine I SSH'ed into, any time it logs to stdout I see it in my local terminal.
How can I ignore this output without monkey patching it on my local machine by passing it to /dev/null? I want to keep the output inside the machine I am SSH'ing to and I want to just leave the SSH altogether after the process starts. I can pass it to /dev/null in the machine, however.
This is an example of what I'm running:
cat ./sh/script.sh | ssh -i ~/.aws/example.pem ec2-user#11.111.11.111
The contents of script.sh looks something like this:
# Some stuff...
# Run binary file
./bin/binary &
Solved it with ./bin/binary &>/dev/null &
Copy the script to the remote machine and then run it remotely. Following commands are executed on your local machine.
$ scp -i /path/to/sshkey /some/script.sh user#remote_machine:/path/to/some/script.sh
# Run the script in the background on the remote machine and pipe the output to a logfile. This will also exit from the SSH session right away.
$ ssh -i /path/to/sshkey \
user#remote_machine "/path/to/some/script.sh &> /path/to/some/logfile &"
Note, logfile will be created on the remote machine.
# View the log file while the process is executing
$ ssh -i /path/to/sshkey user#remote_machine "tail -f /path/to/some/logfile"

Is it possible to run multiple command with remote command option in putty?

I want to run multiple commands automatically like sudo bash, ssh server01, ls , cd /tmp etc at server login..
I am using Remote command option under SSH in putty.
I tried multiple commands with delimiter && but not working.
There is a some information lacking in your question.
You say you want to run sudo bash, then ssh server01.
Will sudo prompt for a password in your remote server?
Assuming there is no password in sudo, running bash will open another shell waiting for user input. The command ssh server01 will not be run until that bash shell is exited.
If you want to run 2 commands, try first simpler ones like:
ls -l /tmp ; echo "hi there"
or if you prefer:
ls -l /tmp && echo "hi there"
Does this work?
If what you want is to run ssh after running bash, you can try :
sudo bash -c "ssh server01"
That is probably because the command is expected to be a program name followed by parameters, which will be passed directly to the program. In order to get && and other functionality that is provided by a command line interpreter such as bash, try this:
/bin/bash -c "command1 && command2"
I tried what I suggested in my previous answer.
It is possible to run 2 simple commands in putty separated by a semicolon. As in my example I tried with ls and echo. The remote server runs them and then the session closes.
I also tried to ssh to a remote server that is configured for not asking for a password. In that case, it also works, I get connected to the 2nd server and I can run commands on it. Upon exit, the 2 connections are closed.
So please, let us know what you actually need / want.
You can execute two consecutive commands in PuTTY using a regular shell syntax. E.g. using ; or &&.
But you want to execute ssh server01 in sudo bash shell, right?
These are not two consecutive commands, it's ssh server01 command executed within sudo bash.
So you have to use a sudo command-line syntax to execute the ssh server01, like
sudo bash ssh server01

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