In a blue-green deployment strategy, there are always two instances of your application running in production. A reverse proxy is used to direct traffic to either the green or the blue version. You then deploy changes to your application by first updating the inactive version and then changing the load balancer config to redirect traffic to the updated instance.
In this video, I will show you how to set up a very simple version of such a blue-green deployment using just Apache, Docker and CentOS 8.
Imagine you work on an application on a development server for several months until it is time to deploy it to a production system for the first time. Chances are, there are several necessary configuration tasks just waiting to be forgotten: firewall permissions, specific software libraries, file permissions and so on.
Ansible offers a reproducible and automatable way to take care of these configurational changes for you – and the beauty is: it does not depend on a specific Linux flavour and it works both for single-machine deployments and distributed systems.
If you were never wondering why your application exits with an HTTP error until you have noticed that the cache folder did not have the correct permissions, stop reading; if you have never forgotten which libraries you had to apt-get install before the Makefile finally completed without errors, this is not the guide for you. Otherwise, see how a simple 50 line yml file can take care of your deployment challenges.