Configuration-based discovery client

The simplest form of service discovery is by storing the list of app instances in .NET configuration.

Configuration settings

An app instance in configuration contains the following keys:

Key	Description
`ServiceId`	The app friendly name.
`Host`	The hostname or IP address of the service instance.
`Port`	The port number the service instance is listening on.
`IsSecure`	Whether to use HTTP or HTTPS to access the service instance.

For example, the appsettings.json file below adds one instance of "billingService" and two instances of "shippingService".

{
  "Discovery": {
    "Services": [
      {
        "ServiceId": "billingService",
        "Host": "192.168.0.1",
        "Port": "5000",
        "IsSecure": false
      },
      {
        "ServiceId": "shippingService",
        "Host": "one.internal.shipping.company.com",
        "Port": "888",
        "IsSecure": true
      },
      {
        "ServiceId": "shippingService",
        "Host": "two.internal.shipping.company.com",
        "Port": "999",
        "IsSecure": true
      }
    ]
  }
}

Using the above configuration, sending an HTTP request to http://shippingService/api?id=123 with Steeltoe service discovery activated would send the request to either:

https://one.internal.shipping.company.com:888/api?id=123
https://two.internal.shipping.company.com:999/api?id=123

The chosen instance depends on the load balancer strategy, which defaults to random.

Table of Contents

Configuration-based discovery client

Configuration settings