Call the Wanaku services API

ServicesHttpClient sends requests to Wanaku Barn and to the Wanaku management API, and returns the results as SDK types. This guide shows how to configure the client, authenticate, and use its operations.

Prerequisites

• The capabilities-services-client module. See Get started.
• The address of a Wanaku Barn instance, of a Wanaku server, or of both.

Configure the client

Create a ServiceConfig with DefaultServiceConfig.Builder, then give it to the client:

ServiceConfig config = DefaultServiceConfig.Builder.newBuilder()
        .baseUrl("http://localhost:8180")
        .serializer(new JacksonSerializer())
        .build();

ServicesHttpClient client = new ServicesHttpClient(config);

Builder method	Value
baseUrl	The server URL. The client adds the /api/v1/... paths to it. A trailing / is removed.
serializer	The JSON serializer. Use JacksonSerializer.
clientId	The OAuth2 client ID. Optional.
secret	The OAuth2 client secret. Optional.
tokenEndpoint	The OIDC realm URL, or its /protocol/openid-connect/token URL. Optional.

One client has one base URL. Select it for the operations that you use (see Use the operations):

• For the Barn operations, use the Barn backend, for example http://localhost:8180, or the Wanaku plugin proxy for Barn, for example http://localhost:8080/api/plugins/wanaku-barn/wanaku-barn-api.
• For the Wanaku operations, use the Wanaku management API, for example http://localhost:8080.

Authenticate

The client supports two methods.

OAuth2 client credentials

Set clientId, secret, and tokenEndpoint. When all three have a value, the client creates a ServiceAuthenticator (from capabilities-security). The authenticator gets an access token with the client credentials grant, renews it before it expires, and adds the Authorization header to each request.

ServiceConfig config = DefaultServiceConfig.Builder.newBuilder()
        .baseUrl("http://localhost:8180")
        .serializer(new JacksonSerializer())
        .clientId("wanaku-service")
        .secret(System.getenv("WANAKU_CLIENT_SECRET"))
        .tokenEndpoint("http://keycloak:8080/realms/wanaku")
        .build();

The authenticator gets the first token in the client constructor. If the OIDC provider is not available, the constructor fails.

Bearer token or other headers

Use the constructor with an HttpClient and a request customizer. The customizer runs on each request, after the OAuth2 header is added:

HttpClient httpClient = HttpClient.newHttpClient();

ServicesHttpClient client = new ServicesHttpClient(config, httpClient, builder -> builder
        .timeout(Duration.ofSeconds(30))
        .setHeader("Authorization", "Bearer " + token));

You own the lifecycle of the HttpClient that you give to this constructor.

Use the operations

Most operations return a WanakuResponse<T>. Read the result with data(). If the server returns a status outside 2xx, the client throws a WanakuWebException (from capabilities-common) with the status code. For an I/O or JSON error, the client throws a WanakuException.

Group	Server	Operations	API path
Data stores	Barn	addDataStore, listDataStores, getDataStoreById, getDataStoresByName, removeDataStore, removeDataStoresByName	/api/v1/data-store
Service catalogs	Barn	getServiceCatalog	/api/v1/service-catalog/download
Service templates	Barn	listServiceTemplates, getServiceTemplate, getServiceTemplateProperties, downloadServiceTemplate, deployServiceTemplate, instantiateServiceTemplate, removeServiceTemplate	/api/v1/service-template/...
Tools	Wanaku	addTool, listTools, getToolByName, updateTool, removeTool	/api/v1/tools
Resources	Wanaku	exposeResource, listResources, updateResource, removeResource	/api/v1/resources
Forwards	Wanaku	addForward, listForwards, updateForward, removeForward	/api/v1/forwards
Namespaces	Wanaku	listNamespaces	/api/v1/namespaces

getServiceCatalog returns a DataStore. Its data field holds the catalog ZIP archive as Base64 text. To extract it, see Load service catalogs and routes.

Next steps

• Load service catalogs and routes: extract a catalog and load its Camel routes.
• API types: the types that the client returns.