Microservices

What are microservices? #

Microservices are a specialization of a service-oriented architecture (SOA), flexible, independently deployable software.

Microservices are an architectural style that structures an application as a collection of loosely coupled services, which implement business capabilities. The microservice architecture enables the continuous delivery and deployment of large, complex applications by naturally dividing it into smaller pieces. Key characteristics of microservices:

• Highly maintainable and testable
• Loosely coupled
• Independently deployable
• Organized around business capabilities
• Owned by a small team

This definition encapsulate the logic we encourage you to use when deploying edge applications on your nodes . But we would add a couple of points to really nail the Edgeworx Cloud Application Microservice:

• It is a docker container that runs on your node
• Its life-cycle is managed by your Edgeworx Agent
• Microservices are leveraged within your edge Application

Writing microservices #

Your microservices can do anything a Docker conaainer can do, from interacting with the physical hardware to hosting a web server. That means most off-the-shelf frameworks and libraries in your favorite language work too.

But because most Edge Compute Networks contain multiple, sometimes even hundreds or thousands, of nodes running in a distributed fashion, ioFog provides an SDK library you can use to ease the burden of communicating between them. The SDK also provides the ability to receive dynamic configuration in your microservice so you don’t have to bake them into your containers.

Packaging microservices #

The high-level process of creating a new microservice is:

• Create a project directory
• Create a Dockerfile with your desired configuration
• Write the microservice app code itself
• Build the image with docker build
• Deploy your image to a Docker registry (e.g. Docker Hub)
• (Optional) Add the registered image to your Controller’s catalog
• Deploy the microservice using edgectl

If you’re new to containers and Docker, you’ll want to check out their official Getting Started guide which walks you through the different pieces of putting together a Docker container image.

Connecting microservices to edge application #

Once you deploy microservice(s), you’re ready to connect them to your Application!