I need to open an ssh connection on login and keep it open, but to not acutally do anything with it. It would be best if all of it would run in the background.
I created an automator application and made it run a shell script on the bash. The script looks as follows:
sshpass -p 123456 ssh 123456#123.123.123.123
If i try to run the application i keep getting an error message, however if i execute the exact same script in an terminal it works just fine.
Is there any way i can open that connection with an automator application and keep in the background?
You can send a KeepAlive packet to stop the pipe from closing.
In your ~/.ssh/config, and the following:
Host *
ServerAliveInterval 300
ServerAliveCountMax 2
What this says is that that every 300 seconds, send a null (keep-alive) packet and give up after 2 tries.
Source: http://patrickmylund.com/blog/how-to-keep-alive-ssh-sessions/
Do you really need to involve Automator at all?
Just save the script (say, foo.sh) in a folder with the same name as the script (i.e. foo.sh as well).
Put this folder in /System/Library/StartupItems/ and it will run when you start up your machine.
Related
I have a bash script that I have to regularly run on a remote server. Part of the script includes running a backup which takes a while, and after it has run, I have to hit "Y" to confirm that the backup worked before the script will continue.
I would like to know if there is a way to get my laptop to make a beep (or some sort of sound) when that happens. I know that echo -e '\a' makes a beep, but if I run it from within a script on the remote server, the beep happens on the remote server.
I have control of the script that is being run, so I could easily change it to do something special.
You could send the command through ssh back to your computer like:
ssh user#host "echo -e '\a'"
Just make sure you have ssh key authentication from your server to your computer so the command can run smoothly
In my case the offered solutions with echo didn't work. I'm using a macbook and connect to an ubuntu system. I keep the terminal open and I'd like to be informed when a long running bash script is ready.
What I did notice is that if I shutdown the remote system then it will beep the macbook and show an alarm icon on the relevant tab. So I have now implemented a bit of dirty workaround:
sudo shutdown 1440 && shutdown -c
This will initiate the system to shutdown and will immediately cancel the request. And I do get the alarm beep + icon. You will need to setup sudo to allow the user to permit shutdown. As it was my own remote server it was no problem but could limit the usability for others.
I am currently trying to load test our instance hosting a postgres instance from a bash script. The idea is to spawn a bunch of open connections (without running any queries) and then checking the memory.
To spawn a bunch of connections I do:
export PGPASSWORD="$password"
for i in $(seq 1 $maxConnections);
do
sleep 0.2
psql -h "$serverAddress" -U postgres >/dev/null &
done
However, it seems that the connections don't stay open, as when I check for active connections, I get 0 from the ip of the instance I'm running it from. However, if I do
psql -h "$serverAddress" -U postgres &
manually from the shell, it keeps the connection open. How would I open and maintain open connections within a bash script? I've checked the password is correct, and if I exclude the ampersand from within the script, then I do enter the psql console with an open connection as expected. It's just when I background it in the script that it causes problems.
You can start your psql sessions in a sub-shell while you loop by using the sub-shell parentheses syntax like below. However, if you do this I recommend you write code to manage your jobs and clean them up when you are done.
(psql -h "$serverAddress" -U postgres)&
I tested this and I was able to maintain connections to a postgres instance this way. However, if you are checking for active connection via a select statement like select * from pg_stat_activity; you will see these connections as open and idle to the instance not active as they are not executing any task or query.
If you put this code in a script an execute it you will need to make sure that the script does not terminate before you are ready for all the sessions to die.
I am trying to do some work on a remote machine and disconnect without terminating the work. I have tried both nohup and screen, unfortunately it is not working out. After I type exit to logout my work also terminates immediately.
I am trying to run 108 simulations on a remote machine. For that purpose I have written a script named batch.sh which runs one simulation after the other until all 108 are done. The program that actually runs a simulation launches 5 programs in 5 different terminals (using xterm -e). I run batch.sh using:
nohup bash batch.sh &
As long as I am connected everything works just fine. If I disconnect and then reconnect to check whether everything is working as it should...no joy :(
Are there any caveats I am overlooking? Possibly because my program launches other programs in external terminals?
UPDATE
If I use the suggestions of adding -oForwardX11=no to ssh and unset DISPLAY before launching my script I get these errors:
nohup: ignoring input and appending output to nohup.out
In nohup.out I have these messages:
xterm Xt error: Can't open display:
xterm: DISPLAY is not set
Apparently your script/program is trying to launch xterm on its own. These days many systems enable X11 forwarding for their SSH client by default - as a result the DISPLAY variable is set in your shell session but becomes invalid once you disconnect. Therefore, as long as you are connected to the remote system, the xterm processes can access the X server on your local machine through the SSH connection, but die once that connection is severed.
I have occasionally encountered the same issue with Java programs that use e.g. the Java AWT subsystem to generate image files, even when there is no actual graphical window. You should first see if your program will somehow adapt if there is no X server available. One option is to disable X11 forwarding with the -oForwardX11=no option to ssh:
$ ssh -oForwardX11=no user#server.host.name
You could also try unsetting the DISPLAY environment variable before starting your script and see what happens.
However, if your program is launching xterm windows indiscriminately then you'd have to make it e.g. use an output file on the server instead - by modifying it, if necessary. As an added advantage, you would get rid off the network load and timing overhead involved with forwarded X connections.
If you cannot change the way your program works and you do not actually care about the output in those xterm windows, then you could try launching a virtual framebuffer X server on the remote system and have your script use that for xterm.
What's the best way to run this shell script where I need to create an output log at the same time run it in the background? The catch is, I need to input a couple of parameters then enter a password.
For example I execute the shell script like so:
-bash-4.3$ ./tst.sh param1 param2 >> tst.log
Password for user mas:
I need to pass in (2) parameters, then prompted for a password:
./tsh.sh <param1> <param2>
This will work, but I have to keep the session open and I want it so it goes to the background or something similar where it will continue to run if my connection to the host fails..
If you want to run something that will survive if your connection fails you should run it in a screen or tmux session. You can use those to create sessions that you can disconnect from and reconnect to, and many other really cool things once you start really getting into them.
So if you ssh in and then run screen you'll still be at a bash prompt, but if you run a command then press ^a^d you will detach from that session. Everything running inside screen will keep going, and you'll be able to reconnect with screen -x later. You can have many screen sessions at the same time too, use screen -ls to see which are running then you can use screen -x <id> to reconnect to a particular one.
I have a bash script that tests whether the sftp connection exists, very simple one:
$ if [ -d ~/.gvfs/sftp for username on 192.168.1.101 ]; then echo "sftp missing" exit; fi
Now heres the question:
How do I make the script reestablish the previously connected sftp that still has a cached pass to reconnect without having it depend on if the bash script is on?
Since I have a bookmarked sftp thing in nautilus, i just point and click, presto its reconnected. I need the same for my script which will TERMINATE in a couple of lines; in other words the script only reconnects nautilus and dies, connection stays open...
I am still noobish at sftp, besides connecting...
Extra info: I use Ubuntu for both client and server, and i dont mind entering the ssh pass again if its new conection, any help is appreciated :D
Its critical that sftp wont d/c, or die, when i close script, or it ends, nohup cant be used for script since it will be run >10 times per day
Thanks!
Okay, some research done. You are using the GVFS (GNOME Virtual File System), and are looking with a none-GNOME application (bash) on the FUSE mount point of one of the URIs.
I think you can use the gvfs-mount command to reconnect, if you know the SFTP URL, but I didn't really find much documentation about this.