Purpose

The purpose of the document is to describe the nature and operation of the minOE Runtime.

Intended Readers

The intended readers of this document are software developers, system engineers, application architects, deployment personnel and other technical professionals who want to understand the details of working with mimOE Runtime.

What You Will Learn from this Document

After reading this document you will:

• Understand how the mimOE Runtime turns an independent computing device such as a cell phone into a server on the hybrid edgeCloud
• Understand how to register an edge computing device such as a cell phone with the hybrid edgeCloud using the mimOE Runtime
• Understand how to use the mimOE runtime to deploy and run a microservice on a hybrid edgeCloud
• Have a working knowledge of the runtime resources and services that the mimOE Runtime makes available to microservice automatically

What You Need to Know Before You Start

In order to get the full benefit from reading this document, you need to have:

• A general understanding of edge computing and the Internet of Things (IoT).
• A general understanding of the nature of microservices

Understanding the mimOE Runtime

The mimOE Runtime is a binary file that can be installed on a variety of computing devices such as a desktop computer, laptop computer or Internet of Things device (IoT). for example, an embedded system or a cable television set-top box. Also, you can install the mimOE Runtime on a mobile device such as a cell phone or mobile tablet.

The mimOE Runtime will run on any device that has an operating system that the runtime supports. The following list describes the operating systems supported by the mimOE Runtime

• Android
• iOS
• Windows
• macOS
• Raspian
• Linux Ubuntu
• Beaglebone
• QNX

The mimOE Runtime serves as an intermediary between the host operating system and the code running a mimOE microservice. (See Figure 1, below.)

Figure 1: mimOE interacts with the host operating system to provide a serverless environment upon which to run a custom microservice

When a computing device has the mimOE Runtime installed that computing device is deemed to be a node within an edge Service Mesh cluster.

The Benefits of the mimOE Runtime

The benefits of using the mimOE Runtime are as follows.

• As mentioned above once the mimOE Runtime is up and running on a computing device, that device is part of a mimOE Cluster within an edge Service Mesh cluster.
• The mimOE Runtime provides all the capabilities required to run a RESTful microservice. By default, the mimOE Runtime installs an HTTP web server automatically. All microservice endpoints running on the node have access to the HTTP web server as a shared resource.
• Once a microservice is deployed on a device running the mimOE Runtime, that microservice has access to other nodes running within a given mimOE Cluster. Access to the nodes is facilitated using the edge Service Mesh in conjunction with the mimOE API to do service discovery and then once identified, microservices in the other nodes can be called to accomplish specific tasks.

Creating mimOE Nodes Using the mimOE Runtime

As mentioned above, creating a mimOE node requires installing the mimOE Runtime on a specific device. The particular steps for installing the mimOE Runtime on a computing device are described in the tutorial, Installing mimOE and the mimik-edge-cli Tool on a Linux System or MacOS found in the Tutorials section of this Developer Portal documentation.

Registering a mimOE Node to a user account

Registering a mimOE node to devices running the mimOE Runtime is done automatically when installing the mimOE Runtime on a particular computing device.

However, additional steps are required in order to associate a node running the mimOE Runtime with a particular mimik/mimOE user account. This association is done using the mimik Command Line Tool to create an Access Token from within a node running the mimOE Runtime. An Access Token binds the mimOE node to a particular user account.

The conceptual details about an Access Token are covered in the Key Concept document, Understanding Runtime Tokens. The instructions for using the mimik Command Line Tool to create an Access Token that binds a mimOE node to a user account and thus grants access to the mimOE API and other mimOE nodes are described in the tutorial, QuickStart .

Deploying and running a microservice on an edge computing device

As mentioned previously, once the mimOE Runtime is up and running on an edge computing device, developers can deploy an edge microservice on the particular device. Deploying a microservice on a device running the mimOE Runtime requires understanding mimOE Images and mimOE Containers.

The details of mimOE Images and mimOE Containers are covered in the Key Concepts document, Understanding mimOE Images and mimOE Containers.

In short, developers wanting to make a microservice that runs on the mimOE Runtime will create a custom Node.js project that has the code for the logic of the particular microservice. This custom Node.JS is called an mimOE Image.

You can think of the mimOE Image defined in the Node.js project as a template from which the mimOE container is created. Developers use the mimik Command Line Tool to execute the command set mimik-edge-cli image deploy to create the .tar file that represents the particular mimOE container.

The container's .tar file has a microservice of interest. You'll use the mimik Command Line Tool to execute the command set mimik-edge-cli container deploy to deploy and run the container's microservice on the given mimOE node.

Understanding the runtime computing resources and services provided by the mimOE Runtime

The thing to keep in mind with regard to the mimOE Runtime is that, as mentioned previously, everything you need to run your microservice is provided by the runtime. The microservice's logic is programmed in a custom Node.JS project.

The mimOE Runtime provides the HTTP web server upon which your RESTful microservice will run. Also, the mimOE Runtime provides access to the edge Service Mesh, which in turn allows your code to discover and use other microservices running on different nodes in the.

In effect, the mimOE Runtime provides a serverless computing environment for running microservices.