sudo: sorry, you must have a tty to run sudo

Shell Programming and Scripting
1

Hi, Have a need to run the below command as a "karuser" from a java class which will is running as "root" user. When we are trying to run the below command from java code getting the below error.

Command:

sudo -u karuser -s /bin/bash /bank/karunix/bin/build_cycles.sh

Error:

sudo: sorry, you must have a tty to run sudo

Your help will be much appreciated.

thanks

2

You can disable this requirement. Edit your sudoers file, locate the line

Defaults    requiretty

and disable it by putting a comment sign in front of the line.

3

Hi, Our system administrator informed that this ption can not be disabled due to security issues. Other than disabling 'requiretty' is there anyway to make this command work?

4

You have to create a pseudo terminal in one way or another. If you use ssh to connect for example, there is the -t option which does just that.

ssh -t hostname sudo ...

Does java offer a similar option?

5

The problem is not that it's asking for a tty. The problem is that it wants to ask for a password. That's why it wants a tty...

6

If sudo needs a password, then it needs a tty, sure.

But sudo also complains, when it doesn't need a password, because NOPASSWD is in effect. Just had that situation a few days ago. And the reason for this is the requiretty setting in the sudoers file afaik.

ssh user@host sudo.. -> complaint,

ssh -t user@host sudo... -> success without asking for a password,

removing requiretty and ssh user@host sudo.. -> success

7

It's an either-or thing, sure. It might require a TTY for either reason. But if it requires a password, you can get a confusing error about no TTY, because it needs a TTY to ask for a password...

You see similar things when ssh complains about not having an askpass program available. The error isn't actually the lack of an askpass program, of course; the error is that it needs to ask for a password and can't...

8

Manual seem pretty clear about requiretty:

No mention of password prompting here so it looks like you must be on a tty with this.

Note that the requiretty default requirement could be relaxed just for your particular script (/bank/karunix/bin/build_cycles.sh), so no need to open everything else up.

9

As to answer to the OP, I found an example on how to use ssh + sudo in java: JSch - Java Secure Channel - Examples Maybe this helps.