NMIS8 Unix File Permissions

NMIS normally runs under it's own user, all files under the nmis directory should be owned by nmis and in the group nmis.  In order to allow apache to serve the CGI scripts, the nmis group is added to the apache user.

NMIS supplies several tools/scripts to help you get the permissions set correctly and to check that nothing is out of place.

Basic File Permissions

Make nmis user and group own all the files. 

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chown -Rv nmis:nmis <nmisdir># chmod -Rv g+w <nmisdir>

If you decide on a different user and group name, update the NMIS Configuration Config.nmis accordingly.

One of the joys of Unix is granular file permissions, one of the frustrations of Unix is granular file permissions.  To assist we have added a handy script in the admin directory <nmisdir>/admin/fixperms.pl which will read the NMIS Configuration and fix the permissions accordingly. 

/usr/local/nmis8/admin/fixperms.pl

Sample output from fixperms.pl commandcommand 

This script will fix the permissions for NMIS based on the configuration /usr/local/nmis8/admin/../conf/Config.nmis

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The directory to be processed is: /usr/local/nmis8

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The user will be set to: nmis

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The group will be set to: nmis

Apache User File Permissions

As described in the installation guide, the HTTP Daemon user needs to be able to read and write the NMIS files, so you need to put the owner of the HTTP Daemon, this is usually the user apache or www-data.  You can determine by running: 

[root@nmisdev ~]# ps -ef | grep http

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root 3927 1 0 14:14 ? 00:00:00 /usr/sbin/httpd

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apache 3952 3927 0 14:14 ? 00:00:00 /usr/sbin/httpd

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--snip--

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apache 3959 3927 0 14:14 ? 00:00:00 /usr/sbin/httpd

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root 5411 5382 0 14:38 pts/1 00:00:00 grep http

So the HTTP Daemon user is apache in this example.

Modify the Apache user groupsgroups 

usermod -G nmis apache

Then restart the HTTP DaemonDaemon 

service httpd restart

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Stopping httpd: [ OK ]

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Starting httpd: [ OK ]

NMIS Tools and scripts

# optionally audit your config
/usr/local/nmis8/bin/nmis.pl type=audit
# fix your config
/usr/local/nmis8/bin/nmis.pl type=config
# fix permissions
/usr/local/nmis8/admin/fixperms.pl

SELinux Troubleshooting Tip

Sometimes there are things happening on Linux systems which don't make sense, many times it is because SELinux is preventing things.  You can spend alot of time getting SELinux to behave, or you can put it in permissive mode, or disable it, in the NMIS VM it has been disabled.

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