Getting Started with rConfig on CentOS 7

I’ve been a long time user of RANCID for change management on network devices but frankly it’s always left me feeling a little bit of a pain to use and not particularly modern. I recently decided it was time for my OpenNMS/RANCID server to be rebuilt, moving OpenNMS up to a CentOS 7 installation and in doing so thought it was time to start looking around for an network device configuration management alternative. As is many times the way in the SMB space, this isn’t a task that actual budgetary dollars are going to go towards so off to Open Source land I went!  rConfig immediately caught my eye, looking to me like RANCID’s hipper, younger brother what with its built in web GUI (through which you can actually add your devices), scheduled tasks that don’t require you to manually edit cron, etc. The fact that rConfig specifically targets CentOS as its underlaying OS was just a whole other layer of awesomesauce on top of everything else.

While rConfig’s website has a couple of really nice guides once you create a site login and use it, much to my dismay I found that they hadn’t been updated for CentOS 7 and while working through them I found that there are actually some pretty significant differences that effect the setup of rConfig. Some difference of minor (no more iptables, it’s firewalld) but it seems httpd has had a bit of an overhaul. Luckily I was not walking the virgin trail and through some trial, error and most importantly google I’ve now got my system up and running. In this post I’m going to walk through the process of setting up rConfig on a CentOS minimal install with network connectivity with hopes that 1) it may help you, the two reader’s I’ve got, and 2) when I inevitably have to do this again I’ll have documentation at hand.

Before we get into it I will say there are few artistic licenses I’ve taken with rConfig’s basic setup.

  1. I’ll be skipping over the network configuration portion of the basic setup guide. CentOS7 has done a great job of having a single configuration screen at install where you setup your networking among other things.
  2. The system is designed to run on MySQL but for a variety of reasons I prefer MariaDB. The portions of the creator’s config guide that deal with these components are different from what you see here but will work just fine if you do them they way described.
  3. I’m virtualized kind of guy so I’ll be installing the newly supported open-vm-tools as part of the config guide. Of course, if you aren’t installing on ESXi you won’t be needing these.
  4. Finally before proceeding please be sure to go ahead and run a yum update to make sure everything’s up to date and you really do have connectivity.

Disabling Stuff

Even with the minimal installation there are things you need to stop to make things work nice, namely the security measures. If you are installing this in the will this would be a serious no no, but for a smaller shop behind a well configured firewall it should be ok.

vi /etc/sysconfig/selinux

Once in the file you need to change the “ SELINUX=enforcing ” line to “ SELINUX=disabled “. To do that hit “i” and then use vi like notepad with the arrow keys. When done hit Esc to exit insert mode and “ :wq ” to save and exit.

Installing the Prerequisites

Since we did the minimal install there are lots of things we need to install. If you are root on the box you should be able to just cut and paste the following into the cli and everything gets installed. As mentioned in the original Basic Config Guide, you will probably want to cut and past each line to make sure everything gets installed smoothly.

Autostart Services

Now that we’ve installed all that stuff it does us no good if it isn’t running. CentOS 6 used the command chkconfig on|off to control service autostart. In CentOS 7 all service manipulation is now done under the systemctl command. Don’t worry too much, if you use chkconfig or service start both at this point will still alias to the correct commands.

Finalize Disable of SELinux

One of the hard parts for me was getting the step 5/6 in the build guide to work correctly. If you don’t do it the install won’t complete, but it also doesn’t work right out of the box. To fix this the first line in prerequisites installs the attr package which contains the setfattr executable. Once that’s installed the following checks to see if the ‘.’ is still in the root directories ACLs and removes it from the /home directory. By all means if you know of a better way to accomplish this (I thought of putting the install in the /opt directory) please let me know in the comments or on twitter.

MySQL Secure Installation on MariaDB

MariaDB accepts any commands you would normally use with MySQL. the mysql_secure_installation script is a great way to go from baseline to well secured quickly and is installed by default. The script is designed to

  • Set root password
  • Remove anonymous users
  • Disallow root logon remotely
  • Remove test database and access to it
  • Finally reload the privilege tables

I tend to take all of the defaults with the exception of I allow root login remotely for easier management. Again, this would be a very bad idea for databases with external access.

Then follow the prompts from there.

As a follow up you may want to allow remote access to the database server for management tools such as Navicat or Heidi SQL. To do so enter the following where X.X.X.X is the IP address you will be administering from. Alternatively you can use root@’%’ to allow access from anywhere.

Configure VSFTPd FTP Software

Now that we’ve got the basics of setting up the OS and the underlying applications out of the way let’s get to the business of setting up rConfig for the first time. First we need to edit the sudoers file to allow the apache account access to various applications. Begin editing the sudoers file with the visudo  command, arrow your way to the bottom of the file and enter the following:

rConfig Installation

First you are going to need to download the rConfig zip file from their website. Unfortunately the website doesn’t seem to work with wget so you will need to download it to a computer with a GUI  and then upload it via SFTP to your rConfig server. (ugh) Once the file is uploaded to your /home directory back at your server CLI do the following commands

Next we need to copy the the httpd.conf file over to /etc/httpd/conf directory. This is where I had the most issues of all in that the conf file included is for httpd in CentOS 6 and there are some module differences between 6 and 7. Attached here is a modified version that I was able to get working successfully after a bunch of failures. The file found here (httpd.txt) will need to replace the existing httpd.conf before the webapp will successfully start. If the file is copied to the /home/rconfig directory the shell commands would be

As long as the httpd service starts backup up correctly you should now be good to go with the web portion of the installation which is pretty point and click. Again for the sake of brevity just follow along at the rconfig installation guide starting with section rConfig web installation and follow along to the end. We’ll get into setting up devices in a later post, but it is a pretty simple process if you are used to working with networking command lines.