I’ve read a lot about graph theory recently. They have changed the world a lot. From the simple representation to Bayesian network via Markov chains, the applications are numerous. Today I would like to imagine a graph as a workflow of execution. Every node would be considered as runnable. And every edge would be a dependency. It is an important framework that may be used to as an orchestrator for any model, and of course I am a lot thinkingabout TOSCA
From time to time, I’m involved into a trolling conversation when any linux kiddie tells me: Bash is really the superior shell I totally disagree, but as I’m getting older, I don’t argue anymore. Anyway, in this post I will expose two arguments, or I should say two reasons, why I usually use ksh93 to run my scripts. Note I’m really talking about the engine of the script, (the shebang definition).
About TOSCA The TOSCA acronym stands for Topology and Orchestration Specification for Cloud Applications. It’s an OASIS standard. The purpose of the TOSCA project is to represent an application by its topology and formalize it using the TOSCA grammar. The [TOSCA-Simple-Profile-YAML-v1.0] current specification in YAML introduces the following concepts. TOSCA YAML service template: A YAML document artifact containing a (TOSCA) service template that represents a Cloud application. TOSCA processor: An engine or tool that is capable of parsing and interpreting a TOSCA YAML service template for a particular purpose.
In the cloud computing, alongside of the hosting monsters such as amazon or google, there is the Openstack Platform. Openstack is not a single software, it is more a galaxy of components aim to control the infrastructure, such as hardware pools, storage, network. The management can then be done via a Web based interface or via a bunch of RESTful API. I would like to evaluate its identity service named keystone and use it as a AuthN and AuthZ backend for my simple_iaas example.
In a previous post I have explained how to develop a very simple API server. Without the associated documentation, the API will be useless. Let’s see how we can use swagger-ui in this project to generate a beautiful documentation. Note I’m blogging and experimenting, of course, in the “real” life, it’s a lot better to code the API interface before implementing the middleware. About Swagger Swagger is a framework. On top of the swagger project is composed of several tools.