Understanding service routing through the Gateway

As an extender of API Mediation Layer, review how service routing thorough the Gateway works

Required roles: Zowe extender, application developer

Choose from the following routing methods:

• Understanding service routing through the Gateway
  • Routing with versioning
  • Routing without versioning

Service instances provide information about routing to the API Gateway via Eureka metadata.

Routing with versioning

For basic routing, the gatewayUrl and sericeUrl are specified with the corresponding version:

Example:

routes:

• gatewayUrl: "ui/v1" serviceUrl: "/helloworld"
• gatewayUrl: "api/v1" serviceUrl: "/helloworld/v1"
• gatewayUrl: "api/v2" serviceUrl: "/helloworld/v2"

In this example, the service has a service ID of helloworldservice that exposes the following endpoints:

• UI
  https://gateway/helloworldservice/ui/v1 routed to https://hwServiceHost:port/helloworld/
• API major version 1
  https://gateway/helloworldservice/api/v1 routed to https://hwServiceHost:port/helloworld/v1
• API major version 2
  https://gateway/helloworldservice/api/v2 routed to https://hwServiceHost:port/helloworld/v2

This type of routing has the following features:

• The gatewayUrl is matched against the prefix of the URL path used at the Gateway https://gateway/urlPath, where urlPath is serviceId/prefix/resourcePath.
• The service ID is used to find the service host and port.
• The serviceUrl is used to prefix the resourcePath at the service host.

note

The service ID is not included in the routing metadata, but the service ID is in the basic Eureka metadata.

Routing without versioning

This method of routing is similar to the previous method, but does not use the version part of the URL. This approach is useful for services that handle versioning themselves with different granularity.

One example that only uses a service ID is z/OSMF.

Example:

z/OSMF URL through the Gateway has the following format:

https://gateway:10010/ibmzosmf/api/restjobs/jobs/...

• ibmzosmf
  Specifies the service ID.

• /restjobs/1.0/...
  Specifies the rest of the endpoint segment.

  Note that no version is specified in this URL.