create folder on remote EC2 Instance using Jsch

Question

I want to create a folder on a remote EC2 instance from another EC2 Instance and then copy some data into it as well.

I tried to create folder using JSch and passing command sudo mkdir /data but the error I get is sudo: sorry, you must have a tty to run sudo.Without sudo also, I am unable to create folder. I tried to use ((ChannelExec) channel).setPty(true) and by using this I can create the folder but afterwards I am unable to copy any data and even cant ssh the EC2 Instance from commandline .(if i create folder manualy then copying data is done successfully). can someone please guide me that what should be the way to do it.Thanks

Here at a RHEL 6.3 instance, everything works perfectly with setPty(true); — koppor, Aug 21 '12 at 16:00
how do you stop pseudoterminal. do you use simply setPty(false) or need to do something else also? — waqas, Aug 22 '12 at 09:38

score 0 · Answer 1 · answered Aug 13 '12 at 13:13

0

How about following example?

http://www.jcraft.com/jsch/examples/Sudo.java.html

answered Aug 13 '12 at 13:13

ymnk

1,145
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7

http://stackoverflow.com/questions/11968805/use-of-jsch-sudo-example-and-channel-setpty-for-running-sudo-command-on-remote-h – waqas Aug 15 '12 at 12:06

score 0 · Answer 2 · answered Aug 13 '12 at 17:11

I am not familiar with JSch. But if you have root access, you can update your sudoers configuration file to get around this. Add the following line to /etc/sudoers

Defaults:USERNAME_HERE !requiretty

Maybe someone else can elaborate on whether this is a bad idea or not, that's beyond the scope of my knowledge, but I'd love to know more?

I only use this approcah in one specific situation. We have a cronjob that backs up a cluster of remote servers via rsync, but for rsync to run successfully, it needs sudo privileges.

To get around this I did the following-

Created a user "backupuser" - On both servers local & remote
Added the following two lines to /etc/sudoers - Only needed on the server you want to grant sudo privileges to the user on. In our case, only on the remote server.
```
backupuser ALL = NOPASSWD: /usr/bin/rsync
DEFAULTS:backupuser !requiretty
```

Adding these two lines grants the user, 'backupuser' sudo privileges for rsync command without the need to enter a password and without the required tty connection.

Here's how it works-

The first line breaks down into two parts.

USER SPECIFICATION OPTION_TAG (: CONDITIONS(opt))

USER SPECIFICATION - this sets the user that these options apply(s) too.
```
backupuser
```
OPTION_TAG - the tag for the option you what to grant. In this case, the user is granted sudo privileges without having the enter a password. (see man sudoers for a list of tags available)
```
ALL = NOPASSWD
```
CONDITIONS - You also have the option to place conditions on when to grant sudo privileges. In this case, the user only has sudo privileges to run the rsync command.
```
: /usr/bin/rsync
```

The second line, overrides the default requirement of the sudo command that you need a terminal connection to run sudo (tty requirement). And it grants this privilege only to the user account 'backupuser'. (See man sudoers for the other DEFAULTS)

DEFAULTS:backupuser !requiretty

Hope this helps answer your question. I know it went on a bit of a tangent, but I wanted to give a full explanation. For more info you can also checkout man sudo

Alan thanks for the detailed answer but I think it wont work for me as I am creating EC2 instances on the run and cant change anything in /etc/sudoers without changing its permission settings and for that again I need to use sudo — waqas, Aug 14 '12 at 13:37

create folder on remote EC2 Instance using Jsch

2 Answers2