I am trying to run a command (Jar file execution) on a remote machine using the 'Execute Command' keyword of SSH library. But the control returns even before the command execution is completed. Is there a way to wait until the command is executed?
Below are the keywords written:
Run The Job
[Arguments] ${machine_ip} ${username} ${password} ${file_location} ${KE_ID}
Open Connection ${machine_ip} timeout=60
Login ${username} ${password}
${run_jar_file}= Set Variable java -jar -Dspring.profiles.active=dev ${file_location} Ids=${KE_ID}
${output}= Execute Command ${run_jar_file}
Log ${output}
Sleep 30
Close Connection
Use Read and Write, instead of using "Execute Command" so that you can specify timeout for command execution.
refer: http://robotframework.org/SSHLibrary/latest/SSHLibrary.html#Write
You are explicitly asking for the command to be run in the background (by virtue of adding & as the last character in the command to be run), so the ssh library has no way of knowing when the program you're running exits. If you want to wait for it to finish, don't run it in the background.
In other words, remove the trailing & from the command you are running.
If anyone is still strugling with this one, i have discovered solution
Open Connection ${SSH_HOST} timeout=10s
Login login pass
Write your_command
Set Client Configuration prompt=$
${output}= Read Until Prompt
Should End With ${output} ~ $
Related
here's a problem that is driving me nuts. First off, I am not a Linux expert, so I might just be missing some detail.
I am trying to restart an application (namely rpi-webrtc-streamer, but that shouldn't matter) using a shell script. The reason is that when a configuration change happens I need to update the config files and restart.
The idea is to call a bash script using system() function and pass in the pid of the current process. The script should then just kill the process using the supplied pid, and execute it again. In theory this shouldn't be a problem...
What may be complicating it is that the process needs to run with sudo. Not sure if that's the case but just thought I should mention it.
Now this is the script:
#!/bin/bash
echo "restarting streamer..."
echo "killing process with PID $1"
kill $1
# I have tried different intervals, even 10 seconds, doesn't help
sleep 2
echo "running new streamer instance"
echo "path:"
pwd
#printenv
echo "id -u"
# just to verify the script runs with sudo
id -u
./webrtc-streamer --verbose
echo "done"
The problem is that the application fails with the following error:
(direct_socket.cc:77): Failed to listen 0.0.0.0:8888.
... and then it shuts down. Well obviously it's not able open the port. It almost looks as if the previous instance of the app is still holding the port open. I have however tried tweaking the sleep amount of seconds in the script but that shouldn't be a problem, first I think the script will continue execution after the process is actually killed and second the process shuts down immediately anyway, I can see that from the logs.
If I however run the app immediately after the script fails from the shell that actually executed the initial app in the first place, it runs without any issues (being able to open the port). No matter how much seconds it waited in the sleep previously.
The only other thing I though of would be that the bash script might be running with different environment variables. I tried to print those but I don't see anything significant.
Also I verified that the app does not change the working directory, but that again should not be a problem as it actually launches. It then just exits after not being able to open the port.
I also tried adding sudo before the app execution in the script (which shouldn't be necessary AFAIK). Doesn't make a difference.
Any ideas?
As suggested by jordanm in the comments, I solved the problem by using systemd.
So, I'm using Google Cloud Platform and set below startup script
#! /bin/bash
cd /home/user
sudo ./process1
sudo ./process2
I worried about this script because process1 blocks shell and prevent to run sudo ./process2. And it really was. process1 was started successfully but process2 was not started.
I checked that script has no problem with starting process1 and process2. Execute ./process2 via SSH worked but after I close the SSH shell and process2 was stopped too.
How can I start both process in booting time(or even after)?
I tried testing your startup script in my environment,it seems the script works well.
1.You can please try checking process1 and process2 scripts.
2.If you want your process to run in the background even after the SSH session is closed, you can use “&” { your_command & }at the end of your command.
To run a command in the background, add the ampersand symbol (&) at the end of the command:
your_command &
then the script execution continues and isn't blocked. Or use linux internal means to auto run processes on boot.
I have many EC2 instances that retain Celery jobs for processing. To efficiently start the overall task of completing the queue, I have tested AWS-RunBashScript in AWS' SSM with a BASH script that calls a Python script. For example, for a single instance this begins with sh start_celery.sh.
When I run the command in SSM, this is the following output (compare to other output below, after reading on):
/home/ec2-user/dh2o-py/venv/local/lib/python2.7/dist-packages/celery/utils/imports.py:167:
UserWarning: Cannot load celery.commands extension u'flower.command:FlowerCommand':
ImportError('No module named compat',)
namespace, class_name, exc))
/home/ec2-user/dh2o-py/tasks/task_harness.py:49: YAMLLoadWarning: calling yaml.load() without
Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
task_configs = yaml.load(conf)
Running a worker with superuser privileges when the worker accepts messages serialized with pickle is a very bad idea!
If you really want to continue then you have to set the C_FORCE_ROOT
environment variable (but please think about this before you do).
User information: uid=0 euid=0 gid=0 egid=0
failed to run commands: exit status 1
Note that only warnings are thrown. When I SSH to the same instance and run the same command (i.e. sh start_celery.sh), the following (same) output results BUT the process runs:
I have verified that the process does NOT run when doing this via SSM, and I have no idea why. As a work-around, I tried running the sh start_celery.sh command with bootstrapping in user data for each EC2, but that failed too.
So, why does SSM fail to actually run the process that I succeed in doing by actually via SSH to each instance running identical commands? The details below relate to machine and Python configuration:
My Development Environment has already started after all the pre-requisites needed:
vagrant up
vagrant ssh
make membersrvc
make peer
But when trying to Start the membersrvc by doing membersrvc after coming into the folder $ cd $GOPATH/src/github.com/hyperledger/fabric, It is not Responding!
No Response even after One Hour!
Any suggestions?
This is exactly how membersrvc supposed to behave. when you execute membersrvc command you don't see any output whatsoever, however you can verify that it is running by opening a separate terminal window and running
ps -a | grep membersrvc
command.
Besides, as Sergey Balashevich commented, you also need to make sure that membersrvc is started and running beforepeer process will be able to get a valid certificate, which means that you need to start both membersrvc and peer process in separate terminal windows simultaneously.
If you want to run all the processes in a single terminal window you can execute them in background asmembersrvc > result 2>&1 & it will start the process and redirect both stdout and stderr to a result file which you can specify. If you don't care about the output at all - you can use /dev/null instead of specifying the file.
I have a script that takes a lot of time to complete.
Instead of waiting for it to finish, I'd rather just log out and retrieve its output later on.
I've tried;
at -m -t 03030205 -f /path/to/./thescript.pl
nohup /path/to/./thescript.pl &
And I have also verified that the processes actually exist with ps and at -l depending on which scheduling syntax i used.
Both these processes die when I exit out of the shell. Is there a way to keep a script from terminating when I close the connection?
We have crons here and they are set up and are working properly, but I would like to use at or nohup for single-use scripts.
Is there something wrong with my syntax? Are there any other methods to producing the desired outcome?
EDIT:
I cannot use screen or disown - they aren't installed in my HP Unix setup and i am not in the position to install them either
Use screen. It creates a terminal which keeps going when you log out. When you log back in you can switch back to it.
If you want to keep a process running after you log out:
disown -h <pid>
is a useful bash built-in. Unlike nohup, you can run disown on an already-running process.
First, stop your job with control-Z, get the pid from ps (or use echo $!), use bg to send it to the background, then use disown with the -h flag.
Don't forget to background your job or it will be killed when you logout.
This is just a guess, but something I've seen with some versions of ssh and nohup: if you've logged in with ssh then you may need to need to redirect stdout, stderr and stdin to avoid having the session hang when you exit. (One of those may still be attached to the terminal.) I would try:
nohup /path/to/./thescript.pl > whatever.stdout 2> whatever.stderr < /dev/null &
(This is no longer the case with my current versions of ssh and nohup - the latter redirects them if it detects that any is attached to a terminal - but you may be using different versions.)
Syntax for nohup looks ok, but your account may not allow for processes to run after logout. Also, try redirecting the stdout/stderr to a log file or /dev/null.
Run your command in background.
/path/to/./thescript.pl &
To get lits of your background jobs
jobs
Now you can selectively disown any of the above jobs, with its jobid.
disown <jobid>
All the disowned process should be keep on running even after you logged out.