Building MD-SAL-based applications might be a little difficult in the beginning. There are multiple steps involved for building a HelloWorld application, which we are going to explore at the end of this chapter.
In general, an application or module starts with a YANG model. YANG is a language or, better, a format used to build a model. YANG (Yet Another Next Generation) is a mark-up language similar to JSON, but used mainly for modeling.
The YANG model file is then fed to YANG tools--the YANG interpreter engine of ODL-where it generates the other source files where we need to do Java coding.
It might be difficult to get off the ground, but be patient.
The YANG tools engine automatically generates the application scripts and you can continue to code your application using the generated templates.
The following diagram shows the full process of application creation in ODL:
Again, remember that with MD-SAL, applications are created based on models. You will create a model...