Both of these are simply logical extensions of Agile and Lean software development practices. DevOps is one particular instance of the Agile multi-functional team. Continuous Delivery is the result of Agile’s practice of automating any repeating process, and in particular enabled by automated tests and continuous integration. And both of those underlying practices are the result of optimizing your process to take any delays out of it, a common Lean practice.
Continuous Delivery is a term for the whole of the process that a DevOps team performs. A Continuous Delivery (CD) process consists of developing software, automating testing, automating deployment, automating infrastructure deployment, and linking those elements so that a pipeline is created that automatically moves developed software through the normal DTAP stages.
So both of these concepts have practices and tools attached, which we’ll discuss in short.
Practices and Tools
One question that often comes up is: “Does the entire team need to suddenly have this skill?”. The answer to that is, of course, “No”. But in the same way that Agile teams have made testing a whole team effort, so operations becomes a whole team effort. The people in the team with deep skills in this area will work together with some of the other team members in the execution of tasks. Those other will learn something about this work, and become able to handle at least the simpler items independently. The ops person can learn how to better structure his scripts, enabling re-use, from developers. Or how to test and monitor the product better from testers.
If you have a well constructed CI solution, it will include building the code, running unit tests, creating a deployment package, and deploying to a test environment. The deployment package will be usable on different environments, with configuration provided separately. You might use tools such the cargo plugin for deployment to test (and further?), and keep a versioned history of all your deployment artefacts in a repository.