add discovery endpoint in the ocm client

pkg/ocm/client/client.go

@@ -228,3 +228,50 @@ func (c *OCMClient) parseNewShareResponse(r *http.Response) (*NewShareResponse,
 	}
 	return nil, errtypes.InternalError(string(body))
 }
+
+// Capabilities contains a set of properties exposed by
+// a remote cloud storage.
+type Capabilities struct {
+	Enabled       bool   `json:"enabled"`
+	APIVersion    string `json:"apiVersion"`
+	EndPoint      string `json:"endPoint"`
+	Provider      string `json:"provider"`
+	ResourceTypes []struct {
+		Name       string   `json:"name"`
+		ShareTypes []string `json:"shareTypes"`
+		Protocols  struct {
+			Webdav *string `json:"webdav"`
+			Webapp *string `json:"webapp"`
+			Datatx *string `json:"datatx"`
+		} `json:"protocols"`
+	} `json:"resourceTypes"`
+	Capabilities []string `json:"capabilities"`
+}
+
+// Discovery returns a number of properties used to discover the capabilities offered by a remote cloud storage.
+// https://cs3org.github.io/OCM-API/docs.html?branch=develop&repo=OCM-API&user=cs3org#/paths/~1ocm-provider/get
+func (c *OCMClient) Discovery(ctx context.Context, endpoint string) (*Capabilities, error) {
+	url, err := url.JoinPath(endpoint, "shares")
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, errors.Wrap(err, "error creating request")
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, errors.Wrap(err, "error doing request")
+	}
+	defer resp.Body.Close()
+
+	var cap Capabilities
+	if err := json.NewDecoder(resp.Body).Decode(&c); err != nil {
+		return nil, err
+	}
+
+	return &cap, nil
+}