I'm attempting to write a bash script in ruby that will start a Resque worker for one of my apps.
The command that I generate from the params given in the console looks like this...
command = "ssh user##{#ip} 'cd /path/to/app; bundle exec rake resque:work QUEUE=#{#queue}&'"
`command`
The command is interpolated correctly and everything looks great. I'm asked to input the password for the ssh command and then nothing happens. I'm pretty sure my syntax is correct for making an ssh connection and running a line of code within that connection. ssh user#host 'execute command'
I've done a simpler command that only runs the mac say terminal command and that worked fine
command = "ssh user##{#ip} 'say #{#queue}'"
`command`
I'm running the rake task in the background because I have used that line once inside ssh and it will only keep the worker alive if you run the process in the background.
Any thoughts? Thanks!
I figured it out.
It was an rvm thing. I need to include . .bash_profile at the beginning of the scripts I wanted to run.
So...
"ssh -f hostname '. .bash_profile && cd /path/to/app && bundle exec rake resque:work QUEUE=queue'" is what I needed to make it work.
Thanks for the help #Casper
Ssh won't exit the session until all processes that were launched by the command argument have finished. It doesn't matter if you run them in the background with &.
To get around this problem just use the -f switch:
-f Requests ssh to go to background just before command execution. This is
useful if ssh is going to ask for passwords or passphrases, but the user
wants it in the background. This implies -n. The recommended way to start
X11 programs at a remote site is with something like ssh -f host xterm.
I.e.
"ssh -f user##{#ip} '... bundle exec rake resque:work QUEUE=#{#queue}'"
EDIT
In fact looking more closely at the problem it seems ssh is just waiting for the remote side to close stdin and stdout. You can test it easily like this:
This hangs:
ssh localhost 'sleep 10 &'
This does not hang:
ssh localhost 'sleep 10 </dev/null >/dev/null &'
So I assume the last version is actually pretty closely equivalent to running with -f.
Related
I confess I am total newbie to Jenkins.
I have
Jenkins-tls
installed on my Mac for experimentation.
I have a remote server that I testing with.
My Jenkins script is ultra simple.
ssh to the remote machine
sudo pm2 ls
the last command just hangs
I run the same 2 commands from the command line and it all works perfectly.
FYI, I need sudo for pm2 since I need to be root to run pm2, without sudo, I get access denied.
Any thoughts?
I believe you make the invalid assumption that jenkins somehow "types" commands after starting ssh to the remote session's command shell. This is not what happens. Instead, it will wait for the ssh command to finish, and only then execute the next command sudo pm2 ls. This never happens, because the ssh session never terminates. You observe this as a "hang".
How to solve this?
If there's only a small number of commands, you can use ssh to run them with
ssh user#remote sudo mp2 ls
ssh user#remote command arg1 arg2
If this gets longer, why not place all commands in a remote script and just run it with
ssh user#remote /path/to/script
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
I'm trying to execute this script on a remote server with requiretty enabled in the sudoers file.
#!/bin/bash
value=$(ssh -tt localhost sudo bash -c hostname)
echo $value
If I run the script using $ ./sample.sh & it stays stopped in the background. Only by using fg I can force the script to run. I think the problem is the missing tty for the output, but what can I do?
... what can I do?
You can stty -tostop.
Well, I'm new to linux so this may be a very newbie kinda of thing, here it goes:
I have a script in which I'm trying to send some different jobs to remote computers (in fact Amazon's EC2 instances), these jobs are in fact the same function which I run with different parameters.
eventually in the script code I have this line:
nohup ssh -fqi key.pem ubuntu#${Instance_Id[idx]} $tmp
if I do:
echo nohup ssh -fqi key.pem ubuntu#${Instance_Id[idx]} $tmp
I get:
nohup ssh -fqi key.pem ubuntu#ec2-72-44-41-228.compute-1.amazonaws.com '(nohup ./Script.sh 11 1&)'
Now the weird thing. If I run the code with no echo in the script it doesnt work! it says in the nohup.out (in my laptop, no nohup.out is created in the remote instance) bash: (nohup ./Script.sh 10 1&): No such file or directory
The file does exist locally and remotely and is chmod +x.
If I simply run the very same script with an echo in front of the problematic line and copy its output and paste in the terminal, it works!.
Any clues welcome, thanks!
Try removing the single quotes from $tmp. It looks like bash is treating (nohup ./Script.sh 10 1&) as the command with no parameters, but technically nohup is the command with the parameters ./Script.sh 10 1.
The problem is the single quotes around the nohup command in your $tmp variable. These don't get used on the shell locally, so SSH passes them verbatim. This means remotely the ssh server tries to interpret (nohup ./Script.sh 10 1&) as a command (looks for a file named that) which there clearly isn't. Make sure you remove the single quotes in $tmp.
I'm currently trying to ssh into a remote machine and run a script, then leave the node with the script running. Below is my script. However, when it runs, the script is successfully run on the machine but ssh session hangs. What's the problem?
ssh -x $username#$node 'rm -rf statuslist
mkdir statuslist
chmod u+x ~/monitor/concat.sh
chmod u+x ~/monitor/script.sh
nohup ./monitor/concat.sh &
exit;'
There are some situations when you want to execute/start some scripts on a remote machine/server (which will terminate automatically) and disconnect from the server.
eg: A script running on a box which when executed
takes a model and copies it to a remote server
creates a script for running a simulation with the model and push it to server
starts the script on the server and disconnect
The duty of the script thus started is to run the simulation in the server and once completed (will take days to complete) copy the results back to client.
I would use the following command:
ssh remoteserver 'nohup /path/to/script `</dev/null` >nohup.out 2>&1 &'
#CKeven, you may put all those commands on one script, push it to the remote server and initiate it as follows:
echo '#!/bin/bash
rm -rf statuslist
mkdir statuslist
chmod u+x ~/monitor/concat.sh
chmod u+x ~/monitor/script.sh
nohup ./monitor/concat.sh &
' > script.sh
chmod u+x script.sh
rsync -azvp script.sh remotehost:/tmp
ssh remotehost '/tmp/script.sh `</dev/null` >nohup.out 2>&1 &'
Hope this works ;-)
Edit:
You can also use
ssh user#host 'screen -S SessionName -d -m "/path/to/executable"'
Which creates a detached screen session and runs target command within it
What do you think about using screen for this? You could run screen via ssh to start the command (concat.sh) and then you'd be able to return to the screen session if you wanted to monitor it (could be handy, depending on what concat does).
To be more specific, try this:
ssh -t $username#$node screen -dm -S testing ./monitor/concat.sh
You should find that the prompt returns immediately, and that concat.sh is running on the remote machine. I'll explain some of the options:
ssh -t makes a TTY. screen needs this.
screen -dm makes it start in "detached" mode. This is like "background" for your purposes.
-S testing gives your screen session a name. It is optional but recommended.
Now, once you've done this, you can go to the remote machine and run this:
screen -r testing
This will attach you to the screen session which contains your program. From there you can control it, kill it, see its output, and so on. Ctrl-A, then d will detach you from the screen session. screen -ls will list all running sessions.
It could be the standard input stream. Try ssh -n ... or ssh -f ....
For me, only this worked:
screen -dmS name sh my-script.sh
This, of course, depends on screen, and lets you attach later, if you ever want stdin or stdout. Screen will terminate itself when my-script.sh ends.
Below is a much more common decision that required some efforts to find, and it really works for me:
#!/usr/bin/bash
theScreenSessionName="test"
theTabNumber="1"
theStuff="date; hostname; cd /usr/local; pwd; /usr/local/bin/top"
echo "this is a test"
ssh -f user#server "/usr/local/bin/screen -x $theScreenSessionName -p $theTabNumber -X stuff \"
$theStuff
\""
It sends $theStuff list of commands to the tab No $theTabNumber of the screen session $theScreenSessionName preliminarily created at the 'server' on behalf of 'user'.
Please be aware of a trailing whitespace after
-X stuff \"
that is sent to overcome a 'stuff' option's glitch. The whitespace and $theStuff in the next line are appended by 'Enter' (^M) keystrokes. DON'T MISS 'EM!
The "this is a test" message is echoed in the initial terminal, and $theStuff commands are really executed inside the mentioned screen/tab.