Is Ansible a replacement for a CI tool like Hudson/Jenkins?
Recently, in our company, we decided to use Ansible for deployment and continuous integration. But when I started using Ansible I didn't find modules for building Java projects with Maven, or modules for running JUnit tests, or JMeter tests.
So, I'm in a doubtful state: it may be I'm using Ansible in a wrong way.
When I looked at Jenkins, it can do things like build, run tests, deploy. The missing thing in Hudson is creating/deleting an instance in cloud environments like AWS.
So, in general, for what purposes do we need to use Ansible/Jenkins? For CI do I need to use a combination of Ansible and Jenkins?
Please throw some light on correct usage of Ansible.
Answer
First, Jenkins and Hudson are basically the same project. I'll refer to it as Jenkins below. See How to choose between Hudson and Jenkins?, Hudson vs Jenkins in 2012, and What is the most notable difference between Jenkins and Hudson from an user perpective? for more.
Second, Ansible isn't meant to be a continuous integration engine. It (generally) doesn't poll git repos and run builds that fail in a sane way.
When can I simply use Jenkins?
If your machine environment and deployment process is very straightforward (such as Heroku or iron that is configured outside of your team), Jenkins may be enough. You can write a custom script that does a deploy as the final build step (or a chained step).
When can I simply use Ansible?
If you only need to "deploy" without needing to build/test, Ansible might be enough. For instance, you can run a deploy from the commandline or using Ansible Tower. This is great for small projects, static sites, etc.
How do they work together?
A good combination is to use Jenkins to build, test, and save artifacts. Add a step to call Ansible or Ansible Tower to handle the actual deployment process. That allows Ansible to handle machine configuration and lets Jenkins handle the CI process.
What are the alternatives to Jenkins?
I strongly recommend Thoughtworks Go (not to be confused with Go the language) instead of Jenkins. Others include CruiseControl, TravisCI, and Integrity.