Run a bash script on startup, before login as a user - bash

I am trying to have my Ubuntu 12.04 LTS server run a bash script I have to start a Minecraft server on start up, prior to log in but as user minecraft. I can have it run as root by placing the following in /etc/rc.local
bash /path/to/script/script.sh
which runs the script as root, I have tried the following in /etc/rc.local
su -c `bash /path/to/script/script.sh` minecraft
but to no avail. Can anyone tell me what I am doing wrong or should be doing instead? The first line of my script is
#!/bin/bash
in case it is important. Thanks much!

Try
su minecraft -c '/bin/bash /path/to/script/script.sh &'
The user should be the first argument to su.
You should use quotes and not ticks for the command argument (-c)
You may want to consider using su -l minecraft to have the script run in an environment which would be similar to that if the user minecraft logged in directly.
Give this a shot and let me know if it works.

Related

How to launch WSL as if I've logged in?

I have a WSL Ubuntu distro that I've set up so that when I login 4 services start working, including a web API that I can test via Swagger to verify it is up and working.
I'm at the point where what I want to do now is start WSL via a script - that is, launch my distro, have all of the services start, and do it from Python. The problem is I cannot even figure out the correct syntax to get WSL to start from PowerShell in a manner where my services start.
Side note: "services" != systemctl (or similar) calls, but just executing bash CLI commands from either my .bashrc or .profile at login.
I've put the commands to execute in .profile & .bashrc. I've configured it both for root execution and non-root user execution. I've taken the commands out of those 2 files and put it into a script in the Windows file system that I pass in on the start of wsl. And I've put that shell script in the WSL file system as well. Nothing seems to work, and sometimes the distro starts and then stops after about 30 seconds.
Some of the PS CLI commands I've tried:
Start-Job -ScriptBlock{ wsl -d distro -u root }
Start-Job -ScriptBlock{ wsl -d distro -u root 'bash -i -l -c /root/bin/start.sh'
Start-Job -ScriptBlock{ wsl -d distro -u root 'bash -i -l -c .\start.sh'
wsl -d distro -u root -- bash -i -l -c /root/bin/start.sh
wsl -d distro -u root -- bash -i -l -c .\start.sh
wsl -d distro -u root -- /root/bin/start.sh
Permutations of the above that I've tried: replace root with my default login, and turning all of the Start-Job bash options into a comma-separated list of single-quoted strings (Ex: 'bash', '-i', '-l', ... ). Nothing I launch from the CLI will allow me access to the web API that is supposed to be hosted on my distro.
Any advice on what to try next?
Not necessarily an answer here as much as troubleshooting tips which will hopefully lead to an answer:
First, most of the forms that you are using seem to be correct. The only ones that absolutely shouldn't work are those that attempt to run the script from the Windows filesystem.
Make sure that you have a shebang line starting your script. I'm assuming you do, but other readers may come across this as well. For the moment, try this form:
#!/usr/bin/env -S bash -li
That's going to have the same effect as the bash -li you tried -- It will source both both interactive startup files such as ~/.bashrc as well as login profiles such as ~/.bash_profile (and /etc/profile.d/*, etc.).
Note that preferably, you won't need the -li. Best practice would be to move anything necessary for the services over from the startup scripts to your start.sh script, and avoid parsing the profile and rc. I need to go update some of my answers, since I just realized I've been guilty of giving some potentially bad advice ...
Specifically, though, I'm wondering if your interactive Bash config has something truly, well, "interactive" in it that might be preventing the automatic running of the script itself. Again, best practice would be for ~/.bashrc to only hold configuration that is needed for interactive shell sessions.
Make sure the script is set as executable (chmod +x start.sh). Again, I'm assuming this is the case for you.
With a shebang line and an executable script, use something like:
wsl -d distro -u root -e /root/bin/start.sh
The -e tells WSL to launch the script directly. Since it has a shebang line, it will be parsed by Bash. Most of the other forms you use above actually run Bash twice - Once when launching WSL and another when it finds the shebang line in the script.
Try some basic troubleshooting for your script like:
Add set -x to the top (right under the shebang line) to turn on script debugging.
Add a ps -efH at the end to show the processes that are running when the script completes
If needed, resort to quick-and-dirty echo statements to show where things have progressed in the script.
I'm hopeful that the above will at least show you the problem, but if not, add the debugging info that you gain from this to your question, and we can troubleshoot further.

Why does following command work in the bash but not from script

I'm experiencing this really weird issue which I just can't understand why it is happening. When I execute following command from my shell manually it works.
sudo -u some-user echo "$SSH_KEY" | /home/some-user/.ssh/authorized_keys
however from a bash script it fails with a message we don't have any permissions.
#!/bin/bash
sudo -u some-user echo "$SSH_KEY" | /home/some-user/.ssh/authorized_keys
Is there any bash option to configure, or can someone explain this behavior?
It looks a bit like a bash security thingy for non interactive terminals or something like that, but I lost my creativity to google for the solution.
I'm running Ubuntu 16.04.
After hours of investigation it seems sudo commands where not executed because of the password prompt which does not occur from the script.
The solution was to first run a sudo command before runnning the script or just runnning the whole script as sudo so you can enter the password one time and the other sudo commands are running without password prompts.

sudo: command not found while using plink

Hi i have created a batch file (run.bat) that after execution connects me to UNIX server with help of plink. But issue starts from this point i have to execute a script after connection to my server the script contains a command sudo -l. After the execution i get the error as mentioned in subject can anyone help me on this issue ??
Batch File-:
"C:\Program Files\PuTTY" plink -ssh -pw Tos#12Ts w44dvftyw#caa1607UX009.wvd.abcd.net /opt/sieb/w44dvftyw/run.sh
Script file(run.sh) -:
#!/bin/bash
sudo -l
It says
sudo: command not found
But when i run my script normally on UNIX server it runs with no issues. What am i missing here to make it work this way please help.
Scripts such as ~/.profile or ~/.bash_profile responsible for setting up the current user's PATH are run only on login shells.
Running sh -c 'somescript' (as performed by ssh host 'somescript') is neither a login shell, nor an interactive shell; thus, it does not gain the benefit of such scripts.
This means that additions to the PATH (in your case, /usr/local/bin) may not be present with commands run in this way.
Among your options:
Pass the PATH you want as part of the command to remotely run. This might look like:
plink -ssh user#host "PATH=/bin:/usr/bin:/usr/local/bin /opt/sieb/w44dvftyw/run.sh"
Embed a working value in the script you're running:
#!/bin/bash
PATH=/bin:/usr/bin:/usr/local/bin
# ...put the rest of your script here.

run inline shell script as root

I have a user, who's a passwordless sudoer. I need to execute shell script file with him, and make him execute one block as sudo. E.g:
su root <<"AS_ROOT"
# do something with my linux
AS_ROOT
But nothing works. I tried:
su - root <<...
sudo -s -- <<...
It barks back at me. I'm on ubuntu 16.04 lts.
Thank you.
As Cyrus points out, su is a different utility to which sudo's configuration doesn't apply.
It sounds like you're looking for something like this:
sudo -s <<'AS_ROOT'
echo "Hi from $USER."
AS_ROOT
This should output Hi from root.
Note that -s is needed to tell sudo to create a shell in order to interpret the commands passed via stdin (the here-doc). That shell is the current user's default shell, as reflected in environment variable $SHELL.

From cmd, log into Bash and run command in one line

I am developing a TIBCO application and need to be able to run a scp command from an external command resource.
Anyway the issue boils down to being able to log in to bash.exe then run my scp command in the same line.
it works when I run (from cmd.exe)
c:\cygwin\bin\bash.exe --login
(I enter bash)
Then I can run my scp statement just fine
scp account#server:~mysourcedirectory/targetfilename* /cygdrive/c/targetfolder
I want to do these two things in the same line but it doesnt work, aka
c:\cygwin\bin\bash.exe --login -c scp account#server:~mysourcedirectory/targetfilename* /cygdrive/c/targetfolder
will fail. What am I doing wrong and how can i run this command in one go?
Thanks
You have to quote the command.
c:\cygwin\bin\bash.exe --login -c "scp account#server:~mysourcedirectory/targetfilename* /cygdrive/c/targetfolder"
Tested using cmd in wine in gnu/linux. Single quotes did not work, I don't know all the quoting rules for cmd. But the above did work.

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