Category Archives: Linux

Building a custom CentOS 6 kickstart disc, part 1

Note: this series of articles applies to CentOS 6; for CentOS 5, see this series.

CentOS (and of course, it’s upstream distro, Red Hat Enterprise Linux) has an extremely powerful, but somewhat poorly documented, tool for rapidly deploying machines and managing their configuration: kickstart. Kickstart lets you build a custom installation that can run hands-free. So not only is the installation quick and easy for you, you can be confident that your machines are configured exactly the way you want them to be.

Continue reading Building a custom CentOS 6 kickstart disc, part 1

Android Letdowns

After another week or so with Android, I wanted to compile all my gripes in one place.  All in all, I’m happy with my Epic 4G.  It’s a powerful piece of mobile tech with a ton of incredible features.

Caveat: some of these issues may be specific to the Epic 4G and/or Android version 2.1.  I certainly hope some of these are resolved in the supposedly upcoming Froyo build.

Continue reading Android Letdowns

CentOS and the Davis Instruments Vantage Pro 2

We recently upgraded a 13-year-old Davis Instruments weather station to the Vantage Pro 2.  Our old homegrown code wouldn’t work with the new hardware, so we had to find something we could use to get readings off the device.

Enter Andrew McMillan’s superb perl code, which handles all the communications with the Vantage Pro.  We just needed it packaged up for CentOS 5, along with a couple minor fixes (timezone and imperial unit handling).

Here is the RPM and the source RPM.

 

Quick tip for vsftpd and CentOS

I rarely manage FTP servers.  The mere thought of them gives me shivers up and down my spine.  But occasionally, I have to deploy one for one reason or another.  

Here’s a quick tip for you. 

If you’re using vsftpd like me, you might find that you want to create accounts with access to FTP, but not to the shell (no ssh access, for example).  So you might naively want to define the user’s shell as /bin/false in /etc/passwd.

Unfortunately, that will block the user’s access to vsftp as well as ssh.  Instead, under RHEL and CentOS, you should use /sbin/nologin, which will block the ssh access, but continue to allow FTP access.

Even better, as I saw in one forum, you might make a symlink to /sbin/nologin and call it /sbin/ftp_only.  You’ll have to add /sbin/ftp_only to /etc/shells so it will be recognized as a valid shell.  But the advantage here is that you’ll be able to distinguish your FTP-only accounts from accounts that have been disabled for one reason or another.