introduce Client interface

1 files changed, 94 insertions, 0 deletions

diff --git a/client.go b/client.go
new file mode 100644
index 0000000..5f1192b
--- /dev/null
+++ b/client.go
@@ -0,0 +1,94 @@
+/******************************************************************************
+*
+*  Copyright 2018 Stefan Majewsky <majewsky@gmx.net>
+*
+*  Licensed under the Apache License, Version 2.0 (the "License");
+*  you may not use this file except in compliance with the License.
+*  You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+*  Unless required by applicable law or agreed to in writing, software
+*  distributed under the License is distributed on an "AS IS" BASIS,
+*  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+*  See the License for the specific language governing permissions and
+*  limitations under the License.
+*
+******************************************************************************/
+
+package schwift
+
+import (
+	"net/http"
+
+	"github.com/gophercloud/gophercloud"
+)
+
+//Client is the interface between Schwift and the libraries providing
+//authentication for it. Schwift can wrap gophercloud.ServiceClient to provide
+//this interface, so if you have a gophercloud.ServiceClient, use the
+//AccountFromGophercloud method to obtain the corresponding schwift.Account
+//instance.
+type Client interface {
+	//EndpointURL returns the endpoint URL from the Keystone catalog for the
+	//Swift account that this client operates on. It should look like
+	//`http://domain.tld/v1/AUTH_projectid/`.
+	EndpointURL() string
+	//Clone returns a deep clone of this client with the endpoint URL changed to
+	//the given URL.
+	Clone(newEndpointURL string) Client
+	//Do executes the given request after adding to it the X-Auth-Token header
+	//containing the client's current Keystone (or Swift auth) token. It may
+	//also set other headers, such as User-Agent. If the status code returned is
+	//401, it shall attempt to acquire a new auth token and restart the request
+	//with the new token.
+	Do(req *http.Request) (*http.Response, error)
+}
+
+type gophercloudClient struct {
+	c *gophercloud.ServiceClient
+}
+
+func (g *gophercloudClient) EndpointURL() string {
+	return g.c.Endpoint
+}
+
+func (g *gophercloudClient) Clone(newEndpointURL string) Client {
+	clonedClient := *g.c
+	clonedClient.Endpoint = newEndpointURL
+	return &gophercloudClient{&clonedClient}
+}
+
+func (g *gophercloudClient) Do(req *http.Request) (*http.Response, error) {
+	return g.do(req, false)
+}
+
+func (g *gophercloudClient) do(req *http.Request, afterReauth bool) (*http.Response, error) {
+	provider := g.c.ProviderClient
+
+	req.Header.Set("User-Agent", provider.UserAgent.Join())
+	for key, value := range provider.AuthenticatedHeaders() {
+		req.Header.Set(key, value)
+	}
+
+	resp, err := provider.HTTPClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	//detect expired token
+	if resp.StatusCode == http.StatusUnauthorized && !afterReauth {
+		err := drainResponseBody(resp)
+		if err != nil {
+			return nil, err
+		}
+		err = provider.Reauthenticate(resp.Request.Header.Get("X-Auth-Token"))
+		if err != nil {
+			return nil, err
+		}
+		//restart request with new token
+		return g.do(req, true)
+	}
+
+	return resp, nil
+}