Bug Fix - Adding an allowed address pair wipes port security groups

Fix for cloud routes enabled instances will have their security groups
removed when the allowed address pair is added to the instance's port.

Upstream bug report is in:
https://github.com/gophercloud/gophercloud/issues/509

Upstream bug fix is in:
https://github.com/gophercloud/gophercloud/pull/510

vendor/github.com/gophercloud/gophercloud/doc.go

@@ -3,11 +3,17 @@ Package gophercloud provides a multi-vendor interface to OpenStack-compatible
 clouds. The library has a three-level hierarchy: providers, services, and
 resources.
 
-Provider structs represent the service providers that offer and manage a
-collection of services. The IdentityEndpoint is typically refered to as
-"auth_url" in information provided by the cloud operator. Additionally,
-the cloud may refer to TenantID or TenantName as project_id and project_name.
-These are defined like so:
+Authenticating with Providers
+
+Provider structs represent the cloud providers that offer and manage a
+collection of services. You will generally want to create one Provider
+client per OpenStack cloud.
+
+Use your OpenStack credentials to create a Provider client.  The
+IdentityEndpoint is typically refered to as "auth_url" or "OS_AUTH_URL" in
+information provided by the cloud operator. Additionally, the cloud may refer to
+TenantID or TenantName as project_id and project_name. Credentials are
+specified like so:
 
   opts := gophercloud.AuthOptions{
     IdentityEndpoint: "https://openstack.example.com:5000/v2.0",
@@ -18,6 +24,16 @@ These are defined like so:
 
   provider, err := openstack.AuthenticatedClient(opts)
 
+You may also use the openstack.AuthOptionsFromEnv() helper function. This
+function reads in standard environment variables frequently found in an
+OpenStack `openrc` file. Again note that Gophercloud currently uses "tenant"
+instead of "project".
+
+	opts, err := openstack.AuthOptionsFromEnv()
+	provider, err := openstack.AuthenticatedClient(opts)
+
+Service Clients
+
 Service structs are specific to a provider and handle all of the logic and
 operations for a particular OpenStack service. Examples of services include:
 Compute, Object Storage, Block Storage. In order to define one, you need to
@@ -27,6 +43,8 @@ pass in the parent provider, like so:
 
   client := openstack.NewComputeV2(provider, opts)
 
+Resources
+
 Resource structs are the domain models that services make use of in order
 to work with and represent the state of API resources:
 
@@ -62,6 +80,12 @@ of results:
     return true, nil
   })
 
+If you want to obtain the entire collection of pages without doing any
+intermediary processing on each page, you can use the AllPages method:
+
+	allPages, err := servers.List(client, nil).AllPages()
+	allServers, err := servers.ExtractServers(allPages)
+
 This top-level package contains utility functions and data types that are used
 throughout the provider and service packages. Of particular note for end users
 are the AuthOptions and EndpointOpts structs.