Code Snippets

Restart Services On RackSpace Managed Nodes That Require sudo Rights

Recently I was working on a project that was using RightScale to manage RackSpace cloud nodes. One of the requirements of the project was to have application nodes scale automatically thus they were required to automatically install software, configure settings, and start services automatically on the RackSpace CentOS nodes being used. Most everything was fairly straight forward however some of the services we were using would not start properly and initially because of the lack of logging from the services we were unable to figure out what the problem was. Below I describe the problem in more detail along with the solution which involved updating a configuration file on the CentOS Linux servers and then restarting the services.

Code Snippets

RightScale RightScript To Update CentOS iptables Rules On RackSpace Node

Recently while working on some node or instance automation using RightScale I needed to have some extra iptables rules created automatically when a new node booted. Initially I was just trying to do this via iptables commands which I note below but it would never work. After digging through the logs I realized that the iptables commands created by RightScale for the ServerTemplate I was using flushed iptables at the very end of the boot process and thus wiped out the iptables entries created by the RightScript I had created. To accomplish permanent iptables entries for a RackSpace node via RightScale you need to output the iptables command to a file in the location where the boot process picks them up after flushing the current ruleset. Below I describe my first attempt followed by the correct way to have iptables entries picked up by RightScale.

Technology Insights

Create And Mount Amazon AWS EC2 EBS Storage To AWS EC2 Linux Instance

Amazon’s AWS products are pretty amazing and allow you to scale with ease for short or long term projects. One thing that can be helpful is mounting extra storage to AWS instances so you have the ability to unmount the storage and mount to different instances in the future. The other benefit is the ability to terminate an Amazon AWS instance and keep the Elastic Block Store (EBS) volume to use on another AWS instance at a later date. Use the directions below to create an Amazon EC2 EBS volume, attach the volume to an Amazon AWS instance, format the volume, and then mount the volume to the instance.