The command after && doesn't run

tezarin · 12-22-2016, 11:52 AM

Hi all,

I have created a Jenkins job today, what it does is the Jenkins user should log into another server and run two commands separated by &&:

ssh -i /creds/jenkins jenkins@servername.com "sh -c 'sudo su && lxc exec containername bash'"

The logging part works fine, then it runs the sudo su command and becomes root but it never runs the second command.

I even did this manually and from the Jenkins machine logged into the other server (servername). Then ran sh -c "sudo su && lxc exec containername bash" with no luck.

Can you please help?

Turbocapitalist · 12-22-2016, 12:24 PM

The && is an operator that runs the second command only when the first one has finished running and reports success. sudo su probably never finishes and thus never reports success or failure.

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -c 'sudo lxc exec containername bash'"

So if you want lxc to run as root, just use sudo alone.

fatmac · 12-22-2016, 01:53 PM

When you sudo su you are getting a new terminal, & the command doesn't get passed to it.
(As said above, if you just use sudo it should work.)

Shadow_7 · 12-22-2016, 09:15 PM

As previously said: In order for the after && thing to run, the thing before && needs to complete with an exit code 0. If that's not a requirement, perhaps using ";" would better suit.

$ echo -e "echo 1\nexit 0" > test_good.sh
$ echo -e "echo 1\nexit 1" > test_bad.sh

$ sh test_good.sh && echo 2
1
2

$ sh test_bad.sh && echo 2
1

$ sh test_bad.sh; echo 2
1
2

Something like that.

tezarin · 12-23-2016, 09:47 AM

Quote:

Originally Posted by Turbocapitalist

The && is an operator that runs the second command only when the first one has finished running and reports success. sudo su probably never finishes and thus never reports success or failure.

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -c 'sudo lxc exec containername bash'"

So if you want lxc to run as root, just use sudo alone.

Thanks everyone,
I've just tried running the command exactly as you stated and it doesn't work. The command runs and I don't get the prompt back. But If I manually become root, then type the lxc command, it works fine.

Turbocapitalist · 12-23-2016, 10:15 AM

Quote:

Originally Posted by tezarin

Thanks everyone,
I've just tried running the command exactly as you stated and it doesn't work. The command runs and I don't get the prompt back. But If I manually become root, then type the lxc command, it works fine.

Maybe you are missing some needed environment variable or other settings. See if sudo does it with the -i option.

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -c 'sudo -l lxc exec containername bash'"

That will run as a login shell.

tezarin · 12-23-2016, 10:30 AM

Quote:

Originally Posted by Turbocapitalist

Maybe you are missing some needed environment variable or other settings. See if sudo does it with the -i option.

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -c 'sudo -l lxc exec containername bash'"

That will run as a login shell.

Thanks, I just tried it with the -l and this is what I got back on the Jenkins machine: /usr/bin/lxc exec docker bash

So it didn't even log into the servername.com, let alone becoming sudo and running the lxc container.

Turbocapitalist · 12-23-2016, 10:32 AM

Sorry, that was a typo. I wrote -i in the text but put the wrong option in the example. Please try with -i and not -l.

tezarin · 12-23-2016, 12:55 PM

Quote:

Originally Posted by Turbocapitalist

Sorry, that was a typo. I wrote -i in the text but put the wrong option in the example. Please try with -i and not -l.

No problem, I just tried it with -i and got this error: mesg: ttyname failed: Inappropriate ioctl for device

Turbocapitalist · 12-23-2016, 01:18 PM

Ok. That's probably an improvement. I've not used lxc or lxd. However, looking around it might be possible that you need to use lxc-attach instead of straight up lxc, if the container is already running.

tezarin · 12-23-2016, 01:30 PM

Quote:

Originally Posted by Turbocapitalist

Ok. That's probably an improvement. I've not used lxc or lxd. However, looking around it might be possible that you need to use lxc-attach instead of straight up lxc, if the container is already running.

If I run sudo su and become root, then run lxc exec containername bash, everything works fine. I'm puzzled...

Turbocapitalist · 12-23-2016, 01:41 PM

Just guessing here, but what about adding a login option to su?

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -l -c 'sudo -i lxc exec containername bash'"

(This time it really is a -l for the one. sudo should try -i.)

tezarin · 12-23-2016, 02:21 PM

Quote:

Originally Posted by Turbocapitalist

Just guessing here, but what about adding a login option to su?

Code:

ssh -i /creds/jenkins jenkins@servername.com "sh -l -c 'sudo -i lxc exec containername bash'"

(This time it really is a -l for the one. sudo should try -i.)

Thanks again, I tried it and got the same result back: mesg: ttyname failed: Inappropriate ioctl for device

Turbocapitalist · 12-23-2016, 02:29 PM

Ok. One last guess and then I'll have to leave it to others. Add to the above a -t option for ssh to force TTY allocation:

Code:

ssh -t -i /creds/jenkins jenkins@servername.com "sh -l -c 'sudo -i lxc exec containername bash'"

Edit: you might try -tt if -t does not do it.

tezarin · 12-23-2016, 02:55 PM

Quote:

Originally Posted by Turbocapitalist

Ok. One last guess and then I'll have to leave it to others. Add to the above a -t option for ssh to force TTY allocation:

Code:

ssh -t -i /creds/jenkins jenkins@servername.com "sh -l -c 'sudo -i lxc exec containername bash'"

Edit: you might try -tt if -t does not do it.

WOW! -t worked like a charm, thank you so much for your help, I really appreciate it!

Happy Holidays!