When you manage microservice applications, you often need to understand the API interfaces exposed by each service -- methods, parameters, paths, and return types -- without digging into source code. Service contracts describe your microservice APIs based on the OpenAPI specification. Microservice systems operate and run based on service contracts. After you deploy an application to Microservices Engine (MSE), you can inspect its API details directly in the MSE console, with no additional dependencies required in the application.
Service contracts also serve as the foundation for the service test feature, which lets you invoke any API directly from the console.
Capabilities
Service contracts provide the following three capabilities:
| Capability | Description |
|---|---|
| API query | View API details for any service provider or consumer, including method names, parameter lists, and return types. For Spring Cloud services, request methods, request paths, and class names are also available. |
| Swagger annotation parsing | Swagger is the major contributor to the OpenAPI specification and a basic standard tool for describing APIs. If your code uses Swagger or OpenAPI annotations, the parsed values appear in the Description column of the contract page. Swagger 2.0: @ApiOperation, @ApiParam, @ApiImplicitParam. OpenAPI 3.0: @Operation, @Parameter. Parsing results are displayed on the service contract page in the Enterprise Distributed Application Service (EDAS) console. |
| Service testing | Test any API method or path directly from the console, using the parameter and method information collected through the service contract. |
View a service contract
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Log on to the MSE console and select a region in the top navigation bar.
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In the left-side navigation pane, choose Microservices Governance > Service query.
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On the Service query page, find the target service and click its name.
To locate a specific service, use the search fields at the top of the page. You can perform a fuzzy search by the following dimensions:
Filter Use case Service name Search by full or partial service name IP address Search by the IP address of a service instance Application name Search by the name of the deployed application -
In the Service details panel, review the contract information. The panel contains the following sections:
Section Information displayed Basic Information General metadata about the service service provider Provider-side interface details service consumer Consumer-side interface details Interface metadata Metadata associated with the service interface Metadata Metadata Additional metadata about the service If your service uses Swagger annotations, the parsed annotation values appear in the Method Name/Description and Parameters/Description columns.