Reading profile script in non-interactive mode with AIX implementation of ksh - ssh

Please note that this is an AIX related question.
I have a jenkins server running on Redhat which is running a node via SSH on an AIX server.
The commands are run non-interactively using SSH to a user on the AIX machine who has ksh as its standard shell.
The problem is that this build needs a number of environment variables, and i can't seem to get it to work.
I have tried:
Jenkins allows me to set some environment variables for the session. So i tried:
ENV="$HOME/.profile"
I tried creating a .kshrc file containing
. .profile
But none of these approaches seems to make KSH run the .profile script.
The .profile script contains the environment setup for the user i need.
How do i get an AIX implementation of KSH to run my .profile script before executing commands?

You need to specifically tell Jenkins that you want to execute them in ksh shell.
By default, Jenkins runs as sh <commands>.
Add a shebang in your shell command as first line,
#!/bin/ksh

Most shells don't source their .profile files on non-interactive sessions. A simple solution is to source the .profile yourself as part of the command you are sending.
So instead of
yourcommand1; yourcommand2
you should send
. ~/.profile; yourcommand1; yourcommand2
over ssh
UPDATE after reading the comment about Jenkins controlling the ssh command
In the case your ssh command is performed by Jenkins you should have a look at https://wiki.jenkins-ci.org/display/JENKINS/SSH+Slaves+plugin, especially the 'Login profile files' paragraph.
I'd say one of these solutions is best
Set all environment variables from Jenkins using the node's configure page. Install the EnvInject plugin to do this.
Write a wrapper around the java command on the slave that sources your profile script and adjust the JavaPath (also on the node's configure page) to point to that wrapper.

The only way I know of for setting environment variables that will apply for non-interactive shells on AIX is via /etc/environment. I believe this is the correct place, but it will of course then apply to all users and all shells.

Related

How to create a Linux GUI app short cut for WSL2 on Windows10?

I have properly installed and setup WSL2. It works fine.
I also setup X11 forwarding and X server (VcXsrv). I can launch GUI apps such like konsole or gvim or even google-chrome from a bash shell.
Now I want to launch konsole by simply double clicking a short cut on the desktop without launching the bash command mode terminal. How should I do it?
I tried running this in cmd:
> wsl /usr/bin/konsole
and it reports:
qt.qpa.xcb: could not connect to display
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, wayland-egl, wayland, wayland-xcomposite-egl, wayland-xcomposite-glx, xcb.
I'm guessing it is because some X11 forwarding configurations were not properly setup, so I created a k.sh as follows:
#!/usr/bin/bash
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2; exit;}'):0.0
export LIBGL_ALWAYS_INDIRECT=1
/usr/bin/konsole &
The first two lines were the X11 settings in my .bashrc, the last line launches konsole.
It works fine under bash environment; but when I ran
wsl k.sh
from windows cmd environment, it silently quitted without launching the konsole.
I'm out of ideas. What should I do to directly launch konsole or other Linux GUI apps under windows without having to getting into bash?
Thanks in advance.
You are asking about two different command-lines, and while the failures in running them via the wsl command have the same root-cause, the underlying failures are likely slightly different.
In both cases, the wsl <command> invocation results in a non-login, non-interactive shell where the command simply "runs and exits".
Since the shell is non-login/non-interactive, your startup files (such as ~/.bashrc and ~/.bash_profile, among others) are not being processed.
When you run:
wsl /usr/bin/konsole
... the DISPLAY variable is not set, since, as you said, you normally set it in your ~/.bashrc.
Try using:
wsl -e bash -lic "/usr/bin/konsole"
That will force bash to run as a login (-l), interactive (-i) shell. The DISPLAY should be set correctly, and it should run konsole.
Note that the quotes probably aren't necessary in this case, but are useful for delineating the commands you are passing to bash. More complicated command-lines can be passed in via the quotes.
As for:
wsl k.sh
That's likely a similar problem. You are doing the right thing by setting DISPLAY in your script, but I notice that you aren't using a fully-qualified path it. This would normally work, of course, if your script is in a directory on the $PATH.
But I'm guessing that you might add that directory to the $PATH in your startup config, which means (again) that it isn't being set in this non-login, non-interactive shell.
As before, try:
wsl -e bash -lic "k.sh"`
You could also use a fully-qualified path, of course.
And, I'm fairly sure you are going to run into an issue with trying to put konsole in the background via the script. When WSL exits, and the bash shell process ends, the child konsole process will terminate as well.
You could get around this with a nohup in the script, but then you also need to redirect the stderr. It's probably easiest just to move the & from the script itself to the command-line. Change your k.sh to:
#!/usr/bin/bash
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2; exit;}'):0.0
export LIBGL_ALWAYS_INDIRECT=1
/usr/bin/konsole
Then run it with:
wsl -e bash -lic "k.sh &"`
Finally, a side note that when and if you can upgrade to Windows 11, it will automatically create Windows Start Menu entries for any Linux GUI app you install that creates a .desktop file. You can manually create .desktop files to have WSL create Start menu items for most applications.
For reference, in Windows 11 it's easier. To run a GUI application without a terminal window popping up, you just need to call wslg.exe instead of wsl.exe.
So, for example:
target: C:\Windows\System32\wslg.exe konsole
start in: C:\WINDOWS\system32
shortcut key: None
comment: Konsole
This tutorial shows how to install VcXsrv and and edit .bashrc to ensure that the "DISPLAY env var is updated on every restart".
DISPLAY env var needs to be dynamic setting.
I've used it successfully with WSL2 on Windows10 Version 21H2 (OS build 19044.2130) to run Chrome, Edge, and thunar. I'm using the Ubuntu 20.04 Linux distro.
To edit .bashrc follow these instructions.

SSH connection command to embedded OS QNX Neutrino via paramiko [duplicate]

I am trying to run sesu command in Unix server from Python with the help of Paramiko exec_command. However when I am running this command exec_command('sesu test'), I am getting
sh: sesu: not found
When I am running simple ls command it giving me desired output. Only with sesu command it is not working fine.
This is how my code looks like:
import paramiko
host = host
username = username
password = password
port = port
ssh=paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(ip,port,username,password)
stdin,stdout,stderr=ssh.exec_command('sesu test')
stdin.write('Password')
stdin.flush()
outlines=stdout.readlines()
resp=''.join(outlines)
print(resp)
The SSHClient.exec_command by default does not run shell in "login" mode and does not allocate a pseudo terminal for the session. As a consequence a different set of startup scripts is (might be) sourced, than in your regular interactive SSH session (particularly for non-interactive sessions, .bash_profile is not sourced). And/or different branches in the scripts are taken, based on an absence/presence of TERM environment variable.
Possible solutions (in preference order):
Fix the command not to rely on a specific environment. Use a full path to sesu in the command. E.g.:
/bin/sesu test
If you do not know the full path, on common *nix systems, you can use which sesu command in your interactive SSH session.
Fix your startup scripts to set the PATH the same for both interactive and non-interactive sessions.
Try running the script explicitly via login shell (use --login switch with common *nix shells):
bash --login -c "sesu test"
If the command itself relies on a specific environment setup and you cannot fix the startup scripts, you can change the environment in the command itself. Syntax for that depends on the remote system and/or the shell. In common *nix systems, this works:
PATH="$PATH;/path/to/sesu" && sesu test
Another (not recommended) approach is to force the pseudo terminal allocation for the "exec" channel using the get_pty parameter:
stdin,stdout,stderr = ssh.exec_command('sesu test', get_pty=True)
Using the pseudo terminal to automate a command execution can bring you nasty side effects. See for example Is there a simple way to get rid of junk values that come when you SSH using Python's Paramiko library and fetch output from CLI of a remote machine?
You may have a similar problem with LD_LIBRARY_PATH and locating shared objects.
See also:
Environment variable differences when using Paramiko
Certain Unix commands fail with "... not found", when executed through Java using JSch

What is the difference between calling a command via "wsl [command]" and opening a wsl shell and calling "[command]"?

I am using Ubuntu via WSL 2.0 on Windows 10 and would like to run Texlive from the Windows command line. To do so I prepended the Texlive folder to the path in /etc/environment (I also tried a number of other locations eg. $HOME/.bashrc):
C:\Users\scott\Documents>wsl echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
C:\Users\scott\Documents>wsl
scott#SCOTT-PC:/mnt/c/Users/scott/Documents$ echo $PATH
/usr/local/texlive/2020/bin/x86_64-linux:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/mnt/c/Windows/system32:...
Why is there a difference between these two paths? Is it possible to change the first PATH variable?
To be honest, when I first looked at this question, I thought it would be an easy answer. Oh how wrong I was. There are a lot of nuances to how this works.
Let's start with the fairly "easy" part, though. The main difference between the first method and the second:
wsl by itself launches into a login (and interactive) shell
the shell launched with wsl echo $PATH is neither a login shell nor an interactive shell
So the first will source both login scripts (e.g. ~/.profile) and interactive startup scripts (e.g. ~/.bashrc). The second form does not get to source either of these.
You can see this a different way (and get to the solution) with the following commands:
wsl -e bash -c 'echo $PATH'
wsl -e bash -li -c 'echo $PATH'
The -li forces bash to run as a login and interactive shell, thus sourcing all of the applicable startup scripts. And, as #bovquier points out in the comments, a single quote is needed here to prevent PowerShell from interpolating the $ before it gets to Bash. That, or escape it.
You should be able to run TeX Live the same way, just replacing the "echo $PATH" with the startup command you need for TeX Live.
A second option would be to create a script that both adds the path and runs the command, and just launch that script through wsl /path/to/script.sh
That said, I honestly don't think that your current login/interactive PATH is coming from /etc/environment. In my testing, at least, /etc/environment has no use in WSL, and that's to be expected. /etc/environment is only sourced by PAM modules, and with no login check performed by WSL, there's no reason to invoke PAM in either the wsl nor the wsl echo $PATH commands.
I'd expect that you still have the PATH setting in ~/.bashrc or somewhere similar), and that's where the shell is picking it up from at the moment.
While this isn't necessarily critical to understanding the answer, you might also wonder, if /etc/environment isn't used for setting the default (non-login, non-interactive) path in WSL, what is? The answer seems to be that it is hard-coded into the init that starts up WSL. That init is also what appends the Windows path (assuming you don't have that feature disabled in /etc/wsl.conf).

Review all scripts that run after sshing into a machine

Is there a way to review everything that runs when I ssh into a machine?
Somehow when I ssh, it starts out with zsh, which is my default shell, but then later changes to fish shell. Want to find out where the fish shell is being called and delete that line.
Yan can add set -vx very early in your various zsh startup scripts ~/.zprofile, ~/.zshrc, etc. If the swicth to fish occurs even earlier, try the same with the zsh startup script in /etc.

Jenkins SSH remote process is getting killed as soon as the Jenkins SSH plugin returns back

Jenkins version: 1.574
I created a simple job which performs the following:
Using "Execute shell script on remote host using SSH" as one of the BUILD steps, I'm just calling a shell script. This shell script performs stop and start operations on Tomcat to restart an application on the target machine.
I have a valid username, password, port defined for the target SSH server in Jenkins Global settings.
I saw this behavior that when I run a Jenkins job and call the restart script (which gets the application name as parameter $1), it works fine, but as soon as "Execute shell script on remote host using SSH" step completes, I see the new process dies on the remote/target application server.
If I run the script from the target/remote server itself, everything works fine and the new process/PID remains live forever, but running the same script from Jenkins, though I don't see any errors and everything works as expected, the new process dies as soon as the above mentioned SSH step is complete and control comes back to the next BUILD step in Jenkins job OR the Jenkins job is complete.
I saw a few posts/blogs and tried setting: BUILD_ID=dontKillMe in the Jenkins job (in various places i.e. Prepare Environment variables and also using Inject Environment variables...). When the job's particular build# is complete, I can see Environment Variables for that build# does say BUILD_ID=dontKillMe as its value (instead of the default Timestamp tag value).
I tried putting nohup before calling the restart script, i.e.,
nohup restart_tomcat.sh "${app}"
I also tried:
BUILD_ID=dontKillMe nohup restart_tomcat.sh "${app}"
This doesn't give any error and creates a nohup.out file on the remote server (but I'm not worried about it as the restart_tomcat.sh script itself creates its own LOG file which I'm "cat"ing after the restart_tomcat.sh script is complete. cat'ing on the log file is performed using another "Execute shell script on remote host using SSH" build step, and it successfully shows the log file created by the restart script).
I don't know what I'm missing at this point, but as soon as the restart_tomcat.sh step is complete, the new PID/process on the remote/target server dies.
How can I fix this?
I've been through this myself.
On my first iteration, before I knew about Jenkins ProcessTreeKiller, I ended up just daemonizing Tomcat. The Apache Tomcat documentation includes a section on running as a daemon.
You can also try disabling the ProcessTreeKiller for your whole Jenkins instance, if it's relatively small (read the first link for information).
The BUILD_ID=dontKillMe should be passed to the shell, and therefore it should be in your command line, not in Jenkins global configuration or job parameters.
BUILD_ID=dontKillMe restart_tomcat.sh "${app}" should have worked without problems.
You can also try nohup restart_tomcat.sh "${app}" & with the & at the end.
My solution (it worked after trying everything else) in Ubuntu 14.04 (Trusty Tahr) (Amazon AWS - Amazon EC2), Jenkins 1.601:
Exec command: (setsid COMMAND < /dev/null > /dev/null 2>&1 &);
Exec in PTY: DISABLED
// Example COMMAND=socat TCP4-LISTEN:1337,fork TCP4:127.0.0.1:1338
I created this Transfer as my last one.
#!/bin/ksh
export BUILD_ID=dontKillMe
I added the above line to the start of my script and the issue was resolved.