Infrastructure as a Service, like OpenStack and AWS, have made it possible to consume infrastructure on demand. It’s important to understand the ways in which both humans and machines interact with IaaS offerings in order to design optimal systems that leverage all possible automation opportunities. I drew the diagram below to help illustrate. Everything is an API At the heart of IaaS are REST APIs that provide granular access to every resource type, such as compute, storage and network. These APIs provide clarity about which resources are being managed and accommodate the type......
Continue Reading
CloudFoundry defines a Service Broker API which can be implemented and added to a CloudFoundry installation to provide managed services for apps. In order to better understand the way managed services are created and integrated with CloudFoundry (and derivative technologies like Stackato and HP Helion Development Platform), I created an example service and implemented the Service Broker API to manage it. The code for both implementations are on github. https://github.com/dwatrous/cf-echo-service https://github.com/dwatrous/cf-service-broker-python Deploy the services For this exercise I deployed bosh-lite on my Windows 7 laptop. I then follow the documented procedure to push......
Continue Reading
There are some high quality resources that already cover the OpenStack API, so this is a YEA (yet another example) post. See the resources section below for some helpful links. OpenStack APIs provide access to all OpenStack components, such as nova (compute), glance (VM images), swift (object storage), cinder (block storage), keystone (authentication) and neutron (networking). Authentication tokens are valid for a fixed duration, after which they expire and must be replaced. Each service requires it’s own token. Services that are hosted on the same logical server are typically accessible over different ports.......
Continue Reading
For a recent project I found that a RESTful interface would be appropriate. My first inclination was to use Jersey (or one of the JAX-RS implementations available). The environment where this new REST API would deploy is still using Java 1.5. This became a major roadblock when I was found that none of the JAX-RS implementations provide support for the Java 1.5 virtual machine. This is not surprising since it’s few YEARS past EOSL (end of support life) for Java 1.5, but disappointing still the same. After spending a day or so with......
Continue Reading
I did some investigation into building the RESTful API for the software licensing system using wicket. At first I was encouraged that URL management was so easy (nevermind that really old article I just linked to). Wicket Not Ideal for RESTful APIs In the end I decided that wicket was not a good choice for the RESTful API. The crux came in treating HTTP methods differently. In other words, for a given resource URI, I want to do something different for GET, POST, PUT and DELETE. That’s not one of wicket’s strengths, so......
Continue Reading
I’m starting to build out the RESTful API for the software licensing system. The first api call to implement is this http://mysite/api/sitelicenses/?apikey=KEYVAL That came from the initial design documents and implicitly suggests that there is a difference between the resource and parameters passed in when asking for the resource. This distinction is important and came up today when I was thinking about pagination. As the API is defined currently, the above URI would return all site licenses associated with an apikey. The first thought that came to mind was that the number of......
Continue Reading
In the first article in this series, I sketched out some of the basic design ideas for the wordpress plugin licensing system. The next step is to come up with some more concrete details about how the application will work, what information it will manage and what the interfaces will look like when accessing it. I really like using the UML as I flesh out a design. In particular I find the class diagram and activity diagram useful. I frequently make use of stereotypes to extend the meaning of my classes. I’m not......
Continue Reading