sudo in "run script" not possible?

[Anonymous user]

I have a NAS device that does not support any type of automated shutdown in the event of utility power failure but does have a command line interface to gracefully halt system via SSH.

I have setup an IBM T21 laptop with Centos 3 and PCNS 2.2.1
I have configured SSH keys on PCNS client and NAS for passwordless remote SSH command execution
I have configured PCNS on the laptop to monitor an APC AP9619 Network Management Card installed in a SmartUPS-1500
I have configured the "The command file needs this much time to complete (seconds)" parameter to "100"
I have set the "Run this command file (full name)" parameter with the absolute path "/root/shutdown_nas.sh"
I have assured correct permissions and execution bit set for script
I have placed the following into the /root/shtudown_nas.sh file:

<----begin---->
#!/bin/sh
echo "success" >> /root/pcns.log
<----end---->

I execute "tail -f /root/pcns.log" on the laptop to watch the contents of the file
I disconnect primary power from the SmartUPS-1500
I observe "success" is entered into the /root/pcns.log file
I create a user "pcnsd" on the laptop and add to "root" group
I then enter the following into the /root/shutdown_nas.sh file:

<----begin---->
#!/bin/sh
sudo -u pcnsd echo "success" >> /root/pcns.log
<----end---->

I execute "tail -f /root/pcns.log" on the laptop to watch the contents of the file
I execute /root/shutdown_nas.sh on the command line as the "root" user
I observe "success" is entered into the /root/pcns.log file
I disconnect primary power from the SmartUPS-1500
I observe no change in the /root/pcns.log file
I observe the laptop shutdown after approximately 100 seconds

The PCNS daemon appears to be a Java application run as the root user so I cannot for the life of me determine why it does not have permission to execute the sudo command.

I have racked my brain on this one and would appreciate any help or guidance of others more knowledgeable about the PCNS daemon client software.

Thanks !
-=dave

[voidstar_apc · Accepted solution]

I don't have pcns to test this on, but my guess is that the append operation isn't being run under the privileges of user pcnsd. Observe:

test:~ voidstar$ sudo touch pcns.log
test:~ voidstar$ ls -al pcns.log
-rw-r--r-- 1 root voidstar 0 Nov 10 10:20 pcns.log
test:~ voidstar$ sudo echo "hi" >> pcns.log
-bash: pcns.log: Permission denied
test:~ voidstar$ sudo rm -rf pcns.log
test:~ voidstar$

I created pcns.log under sudo, I could delete it, but the append operation failed. This is because the bash interpreter is interpreting the sudo line as:

(sudo echo "hi") >> pcns.log

and therefore appending isn't being done as root. Maybe you should make a 2nd shell script and kickstart that with sudo.

Best of luck

Message was edited by: voidstar