Merge pull request #29726 from anguslees/lb-autodetect

Automatic merge from submit-queue

openstack: Autodetect LBaaS v1 vs v2

```release-note
* openstack: autodetect LBaaS v1/v2 by querying for available extensions.  For most installs, this effectively changes the default from v1 to v2.  Existing installs can add "lb-version = v1" to the provider config file to continue to use v1.
```

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---
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pkg/cloudprovider/providers/openstack/openstack.go

@@ -78,7 +78,7 @@ type LoadBalancer struct {
 }
 
 type LoadBalancerOpts struct {
-	LBVersion         string     `gcfg:"lb-version"` // v1 or v2
+	LBVersion         string     `gcfg:"lb-version"` // overrides autodetection. v1 or v2
 	SubnetId          string     `gcfg:"subnet-id"`  // required
 	FloatingNetworkId string     `gcfg:"floating-network-id"`
 	LBMethod          string     `gcfg:"lb-method"`
@@ -390,13 +390,35 @@ func (os *OpenStack) LoadBalancer() (cloudprovider.LoadBalancer, bool) {
 		return nil, false
 	}
 
+	lbversion := os.lbOpts.LBVersion
+	if lbversion == "" {
+		// No version specified, try newest supported by server
+		netExts, err := networkExtensions(network)
+		if err != nil {
+			glog.Warningf("Failed to list neutron extensions: %v", err)
+			return nil, false
+		}
+
+		if netExts["lbaasv2"] {
+			lbversion = "v2"
+		} else if netExts["lbaas"] {
+			lbversion = "v1"
+		} else {
+			glog.Warningf("Failed to find neutron LBaaS extension (v1 or v2)")
+			return nil, false
+		}
+		glog.V(3).Infof("Using LBaaS extension %v", lbversion)
+	}
+
 	glog.V(1).Info("Claiming to support LoadBalancer")
 
 	if os.lbOpts.LBVersion == "v2" {
 		return &LbaasV2{LoadBalancer{network, compute, os.lbOpts}}, true
-	} else {
-
+	} else if lbversion == "v1" {
 		return &LbaasV1{LoadBalancer{network, compute, os.lbOpts}}, true
+	} else {
+		glog.Warningf("Config error: unrecognised lb-version \"%v\"", lbversion)
+		return nil, false
 	}
 }
 

pkg/cloudprovider/providers/openstack/openstack_loadbalancer.go

@@ -20,6 +20,7 @@ import (
 	"time"
 
 	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/openstack/networking/v2/extensions"
 	"github.com/rackspace/gophercloud/openstack/networking/v2/extensions/layer3/floatingips"
 	"github.com/rackspace/gophercloud/openstack/networking/v2/extensions/lbaas/members"
 	"github.com/rackspace/gophercloud/openstack/networking/v2/extensions/lbaas/monitors"
@@ -55,6 +56,24 @@ type LbaasV2 struct {
 	LoadBalancer
 }
 
+func networkExtensions(client *gophercloud.ServiceClient) (map[string]bool, error) {
+	seen := make(map[string]bool)
+
+	pager := extensions.List(client)
+	err := pager.EachPage(func(page pagination.Page) (bool, error) {
+		exts, err := extensions.ExtractExtensions(page)
+		if err != nil {
+			return false, err
+		}
+		for _, ext := range exts {
+			seen[ext.Alias] = true
+		}
+		return true, nil
+	})
+
+	return seen, err
+}
+
 func getPortIDByIP(client *gophercloud.ServiceClient, ipAddress string) (string, error) {
 	var portID string
 

pkg/cloudprovider/providers/openstack/openstack_test.go

@@ -205,50 +205,29 @@ func TestLoadBalancer(t *testing.T) {
 		t.Skipf("No config found in environment")
 	}
 
-	cfg.LoadBalancer.LBVersion = "v1"
+	versions := []string{"v1", "v2", ""}
 
-	os, err := newOpenStack(cfg)
-	if err != nil {
-		t.Fatalf("Failed to construct/authenticate OpenStack: %s", err)
-	}
+	for _, v := range versions {
+		t.Logf("Trying LBVersion = '%s'\n", v)
+		cfg.LoadBalancer.LBVersion = v
 
-	lb, ok := os.LoadBalancer()
-	if !ok {
-		t.Fatalf("LoadBalancer() returned false - perhaps your stack doesn't support Neutron?")
-	}
+		os, err := newOpenStack(cfg)
+		if err != nil {
+			t.Fatalf("Failed to construct/authenticate OpenStack: %s", err)
+		}
 
-	_, exists, err := lb.GetLoadBalancer(testClusterName, &api.Service{ObjectMeta: api.ObjectMeta{Name: "noexist"}})
-	if err != nil {
-		t.Fatalf("GetLoadBalancer(\"noexist\") returned error: %s", err)
-	}
-	if exists {
-		t.Fatalf("GetLoadBalancer(\"noexist\") returned exists")
-	}
-}
+		lb, ok := os.LoadBalancer()
+		if !ok {
+			t.Fatalf("LoadBalancer() returned false - perhaps your stack doesn't support Neutron?")
+		}
 
-func TestLoadBalancerV2(t *testing.T) {
-	cfg, ok := configFromEnv()
-	if !ok {
-		t.Skipf("No config found in environment")
-	}
-	cfg.LoadBalancer.LBVersion = "v2"
-
-	os, err := newOpenStack(cfg)
-	if err != nil {
-		t.Fatalf("Failed to construct/authenticate OpenStack: %s", err)
-	}
-
-	lbaas, ok := os.LoadBalancer()
-	if !ok {
-		t.Fatalf("LoadBalancer() returned false - perhaps your stack doesn't support Neutron?")
-	}
-
-	_, exists, err := lbaas.GetLoadBalancer(testClusterName, &api.Service{ObjectMeta: api.ObjectMeta{Name: "noexist"}})
-	if err != nil {
-		t.Fatalf("GetLoadBalancer(\"noexist\") returned error: %s", err)
-	}
-	if exists {
-		t.Fatalf("GetLoadBalancer(\"noexist\") returned exists")
+		_, exists, err := lb.GetLoadBalancer(testClusterName, &api.Service{ObjectMeta: api.ObjectMeta{Name: "noexist"}})
+		if err != nil {
+			t.Fatalf("GetLoadBalancer(\"noexist\") returned error: %s", err)
+		}
+		if exists {
+			t.Fatalf("GetLoadBalancer(\"noexist\") returned exists")
+		}
 	}
 }