Add e2e tests

vendor/github.com/gophercloud/gophercloud/FAQ.md

@@ -0,0 +1,148 @@
+# Tips
+
+## Implementing default logging and re-authentication attempts
+
+You can implement custom logging and/or limit re-auth attempts by creating a custom HTTP client
+like the following and setting it as the provider client's HTTP Client (via the
+`gophercloud.ProviderClient.HTTPClient` field):
+
+```go
+//...
+
+// LogRoundTripper satisfies the http.RoundTripper interface and is used to
+// customize the default Gophercloud RoundTripper to allow for logging.
+type LogRoundTripper struct {
+	rt                http.RoundTripper
+	numReauthAttempts int
+}
+
+// newHTTPClient return a custom HTTP client that allows for logging relevant
+// information before and after the HTTP request.
+func newHTTPClient() http.Client {
+	return http.Client{
+		Transport: &LogRoundTripper{
+			rt: http.DefaultTransport,
+		},
+	}
+}
+
+// RoundTrip performs a round-trip HTTP request and logs relevant information about it.
+func (lrt *LogRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
+	glog.Infof("Request URL: %s\n", request.URL)
+
+	response, err := lrt.rt.RoundTrip(request)
+	if response == nil {
+		return nil, err
+	}
+
+	if response.StatusCode == http.StatusUnauthorized {
+		if lrt.numReauthAttempts == 3 {
+			return response, fmt.Errorf("Tried to re-authenticate 3 times with no success.")
+		}
+		lrt.numReauthAttempts++
+	}
+
+	glog.Debugf("Response Status: %s\n", response.Status)
+
+	return response, nil
+}
+
+endpoint := "https://127.0.0.1/auth"
+pc := openstack.NewClient(endpoint)
+pc.HTTPClient = newHTTPClient()
+
+//...
+```
+
+
+## Implementing custom objects
+
+OpenStack request/response objects may differ among variable names or types.
+
+### Custom request objects
+
+To pass custom options to a request, implement the desired `<ACTION>OptsBuilder` interface. For
+example, to pass in
+
+```go
+type MyCreateServerOpts struct {
+	Name string
+	Size int
+}
+```
+
+to `servers.Create`, simply implement the `servers.CreateOptsBuilder` interface:
+
+```go
+func (o MyCreateServeropts) ToServerCreateMap() (map[string]interface{}, error) {
+	return map[string]interface{}{
+		"name": o.Name,
+		"size": o.Size,
+	}, nil
+}
+```
+
+create an instance of your custom options object, and pass it to `servers.Create`:
+
+```go
+// ...
+myOpts := MyCreateServerOpts{
+	Name: "s1",
+	Size: "100",
+}
+server, err := servers.Create(computeClient, myOpts).Extract()
+// ...
+```
+
+### Custom response objects
+
+Some OpenStack services have extensions. Extensions that are supported in Gophercloud can be
+combined to create a custom object:
+
+```go
+// ...
+type MyVolume struct {
+  volumes.Volume
+  tenantattr.VolumeExt
+}
+
+var v struct {
+  MyVolume `json:"volume"`
+}
+
+err := volumes.Get(client, volID).ExtractInto(&v)
+// ...
+```
+
+## Overriding default `UnmarshalJSON` method
+
+For some response objects, a field may be a custom type or may be allowed to take on
+different types. In these cases, overriding the default `UnmarshalJSON` method may be
+necessary. To do this, declare the JSON `struct` field tag as "-" and create an `UnmarshalJSON`
+method on the type:
+
+```go
+// ...
+type MyVolume struct {
+	ID string `json: "id"`
+	TimeCreated time.Time `json: "-"`
+}
+
+func (r *MyVolume) UnmarshalJSON(b []byte) error {
+	type tmp MyVolume
+	var s struct {
+		tmp
+		TimeCreated gophercloud.JSONRFC3339MilliNoZ `json:"created_at"`
+	}
+	err := json.Unmarshal(b, &s)
+	if err != nil {
+		return err
+	}
+	*r = Volume(s.tmp)
+
+	r.TimeCreated = time.Time(s.CreatedAt)
+
+	return err
+}
+// ...
+```