Intent.ApiGateway.Ocelot

This module implements the Ocelot API Gateway in a ASP.NET Core application.

What is Ocelot?

Ocelot is aimed at people using .NET running a microservices / service-oriented architecture that need a unified point of entry into their system. -Website

Modeling API Gateway Routes

The following steps are performed inside the Services designer:

• First you need to add a reference to a Services package containing all the downstream service endpoints.
  • Right-click on the Service package and select Add Package Reference.
  • Locate the Service package from another Intent Architect application that will act as the downstream service.
  • Click on DONE.
• Add downstream endpoints:
  • Right-click on the diagram background and select Add to diagram.
  • Select the downstream endpoints you would like to connect to. They would be in the form of Command/Query/Service endpoints.
  • Click on DONE.
• Add Api Gateway routes:
  • Right-click on the diagram background and add a new Api Gateway Route element.
  • Right-click on it and select New Route Association.
  • Select a downstream endpoint to connect to and click to snap it into place.

Inspect the ocelot.json file

The routes will be generated inside the ocelot.json file:

{
  "Routes": [
  {
      "UpstreamPathTemplate": "/api/clients",
      "UpstreamHttpMethod": [
          "Post"
      ],
      "DownstreamPathTemplate": "/api/clients",
      "DownstreamHttpMethod": "POST",
      "DownstreamHostAndPorts": [
        {
           "Host": "{Clients.Host.Name}"
        }
      ]
  },
  // ...

You will see that each route entry has a Host value corresponding to the package name being imported. This is a substitution of the actual host name and port number.

Configure those services inside the appsettings.json file:

{
  //...
  "Ocelot": {
    "Hosts": {
      "Clients.Host.Name": "https://localhost:44300"
    }
  }
}