Configure Google Authenticator on CentOS 7

Image of laptop with hand holding a skeleton key extending outwards through the display.

Intro

As part of the rebuild on my Plex Media Server using CentOS 7, I had intended to configure Google Authenticator but hadn’t gotten around to doing it yet.  As I got into the process recently I discovered that many of the steps that I had used when configuring my CentOS 6 Digital Ocean droplet were out of date to the point of uselessness.

I also discovered that most of the guides that I found either relied on the older 1.0 code release which was also outdated or used a unknown RPM repo.  As such I decided to write up the process that I followed to use the code downloaded from the official GitHub repository.

NOTE: If you are doing this in an enterprise setting, it is likely that your company has particular settings and restrictions that you may need to adhere to (e.g., not running things as the root user). Also, please note that all of my examples use the CentOS defaults unless specifically noted.

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RHEL7 and ncat changes

One of the tools that I use on a regular basis to test network connectivity updates is the “z” option of netcat.  Apparently when RedHat rolled out the latest version of their distribution of RedHat Enterprise Linux (RHEL) they decided to move to using the nmap-ncat package instead of the nc package.  The command options a very different.

So when attempting to test single port like I would have under previous releases I now use the following syntax:

# echo | nc -w1 $host $port >/dev/null 2>&1 ;echo $?

If the result that is returned is a zero then you have successfully connected to the remote host on the desired port. This also applies to CentOS 7 since it is a “clone” or copyleft port of the RHEL7 binaries.

Creating a firewalld service for Plex Media Server

plex_firewalldI recently rebuilt my Plex Media Server box as a CentOS 7 VM running on Hyper-V on a Windows Server 2012 setup.

When I installed the rpm and started the service I found that I was unable to load the interface on my desktop. I knew that it was running because I installed netstat and I was able to see the port was open for traffic and I was also able to load the interface locally in lynx on the server.

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