Add support for oVirt cloud provider

cluster/ovirt/ovirt-cloud.conf

+# ovirt-cloud.conf
+[connection]
+uri = https://localhost:8443/ovirt-engine/api
+username = admin@internal
+password = admin
+
+[filters]
+# Search queries used to find minions
+vms = tag=kubernetes

cmd/apiserver/plugins.go

@@ -22,4 +22,5 @@ package main
 import (
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/gce"
 	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/vagrant"
+	_ "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider/ovirt"
 )

pkg/cloudprovider/ovirt/ovirt.go

+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 ovirt_cloud
+
+import (
+	"encoding/xml"
+	"io"
+	"io/ioutil"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+
+	"code.google.com/p/gcfg"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider"
+)
+
+type OVirtCloud struct {
+	VmsRequest         *url.URL
+	HostsRequest       *url.URL
+}
+
+type OVirtApiConfig struct {
+	Connection struct {
+		ApiEntry string `gcfg:"uri"`
+		Username string `gcfg:"username"`
+		Password string `gcfg:"password"`
+	}
+	Filters struct {
+		VmsQuery   string `gcfg:"vms"`
+	}
+}
+
+type XmlVmInfo struct {
+	Hostname        string `xml:"guest_info>fqdn"`
+	State		string `xml:"status>state"`
+}
+
+type XmlVmsList struct {
+	XMLName         xml.Name     `xml:"vms"`
+	Vm		[]XmlVmInfo  `xml:"vm"`
+}
+
+func init() {
+	cloudprovider.RegisterCloudProvider("ovirt",
+		func(config io.Reader) (cloudprovider.Interface, error) {
+			return newOVirtCloud(config)
+		})
+}
+
+func newOVirtCloud(config io.Reader) (*OVirtCloud, error) {
+	if config == nil {
+		return nil, fmt.Errorf("missing configuration file for ovirt cloud provider")
+	}
+
+	oVirtConfig := OVirtApiConfig{}
+
+	/* defaults */
+	oVirtConfig.Connection.Username = "admin@internal"
+
+	if  err := gcfg.ReadInto(&oVirtConfig, config); err != nil {
+		return nil, err
+	}
+
+	if oVirtConfig.Connection.ApiEntry == "" {
+		return nil, fmt.Errorf("missing ovirt uri in cloud provider configuration")
+	}
+
+	request, err := url.Parse(oVirtConfig.Connection.ApiEntry)
+	if  err != nil {
+		return nil, err
+	}
+
+	request.Path = path.Join(request.Path, "vms")
+	request.User = url.UserPassword(oVirtConfig.Connection.Username, oVirtConfig.Connection.Password)
+	request.RawQuery = url.Values{"search": {oVirtConfig.Filters.VmsQuery}}.Encode()
+
+	return &OVirtCloud{VmsRequest: request}, nil
+}
+
+// TCPLoadBalancer returns an implementation of TCPLoadBalancer for oVirt cloud
+func (v *OVirtCloud) TCPLoadBalancer() (cloudprovider.TCPLoadBalancer, bool) {
+	return nil, false
+}
+
+// Instances returns an implementation of Instances for oVirt cloud
+func (v *OVirtCloud) Instances() (cloudprovider.Instances, bool) {
+	return v, true
+}
+
+// Zones returns an implementation of Zones for oVirt cloud
+func (v *OVirtCloud) Zones() (cloudprovider.Zones, bool) {
+	return nil, false
+}
+
+// IPAddress returns the address of a particular machine instance
+func (v *OVirtCloud) IPAddress(instance string) (net.IP, error) {
+	// since the instance now is the IP in the ovirt env, this is trivial no-op
+	return net.ParseIP(instance), nil
+}
+
+func getInstancesFromXml(body io.Reader) ([]string, error) {
+	if body == nil {
+		return nil, fmt.Errorf("ovirt rest-api response body is missing")
+	}
+
+	content, err := ioutil.ReadAll(body)
+	if  err != nil {
+		return nil, err
+	}
+
+	vmlist := XmlVmsList{}
+
+	if err := xml.Unmarshal(content, &vmlist); err != nil {
+		return nil, err
+	}
+
+	var instances []string
+
+	for _, vm := range vmlist.Vm {
+		// Always return only vms that are up and running
+		if vm.Hostname != "" && strings.ToLower(vm.State) == "up" {
+			instances = append(instances, vm.Hostname)
+		}
+	}
+
+	return instances, nil
+}
+
+// List enumerates the set of minions instances known by the cloud provider
+func (v *OVirtCloud) List(filter string) ([]string, error) {
+	response, err := http.Get(v.VmsRequest.String())
+	if  err != nil {
+		return nil, err
+	}
+
+	defer response.Body.Close()
+
+	return getInstancesFromXml(response.Body)
+}

pkg/cloudprovider/ovirt/ovirt_test.go

+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 ovirt_cloud
+
+import (
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider"
+)
+
+func TestOVirtCloudConfiguration(t *testing.T) {
+	config1 := (io.Reader)(nil)
+
+	_, err1 := cloudprovider.GetCloudProvider("ovirt", config1)
+	if err1 == nil {
+		t.Fatalf("An error is expected when the configuration is missing")
+	}
+
+	config2 := strings.NewReader("")
+
+	_, err2 := cloudprovider.GetCloudProvider("ovirt", config2)
+	if err2 == nil {
+		t.Fatalf("An error is expected when the configuration is empty")
+	}
+
+	config3 := strings.NewReader(`
+[connection]
+	`)
+
+	_, err3 := cloudprovider.GetCloudProvider("ovirt", config3)
+	if err3 == nil {
+		t.Fatalf("An error is expected when the uri is missing")
+	}
+
+	config4 := strings.NewReader(`
+[connection]
+uri = https://localhost:8443/ovirt-engine/api
+`)
+
+	_, err4 := cloudprovider.GetCloudProvider("ovirt", config4)
+	if err4 != nil {
+		t.Fatalf("Unexpected error creating the provider: %s", err4)
+	}
+}
+
+func TestOVirtCloudXmlParsing(t *testing.T) {
+	body1 := (io.Reader)(nil)
+
+	_, err1 := getInstancesFromXml(body1)
+	if err1 == nil {
+		t.Fatalf("An error is expected when body is missing")
+	}
+
+	body2 := strings.NewReader("")
+
+	_, err2 := getInstancesFromXml(body2)
+	if err2 == nil {
+		t.Fatalf("An error is expected when body is empty")
+	}
+
+	body3 := strings.NewReader(`
+<vms>
+  <vm></vm>
+</vms>
+`)
+
+	instances3, err3 := getInstancesFromXml(body3)
+	if err3 != nil {
+		t.Fatalf("Unexpected error listing instances: %s", err3)
+	}
+	if len(instances3) > 0 {
+		t.Fatalf("Unexpected number of instance(s): %i", len(instances3))
+	}
+
+	body4 := strings.NewReader(`
+<vms>
+  <vm>
+    <status><state>Up</state></status>
+    <guest_info><fqdn>host1</fqdn></guest_info>
+  </vm>
+  <vm>
+    <!-- empty -->
+  </vm>
+  <vm>
+    <status><state>Up</state></status>
+  </vm>
+  <vm>
+    <status><state>Down</state></status>
+    <guest_info><fqdn>host2</fqdn></guest_info>
+  </vm>
+  <vm>
+    <status><state>Up</state></status>
+    <guest_info><fqdn>host3</fqdn></guest_info>
+  </vm>
+</vms>
+`)
+
+	instances4, err4 := getInstancesFromXml(body4)
+	if err4 != nil {
+		t.Fatalf("Unexpected error listing instances: %s", err4)
+	}
+	if len(instances4) != 2 {
+		t.Fatalf("Unexpected number of instance(s): %i", len(instances4))
+	}
+	if instances4[0] != "host1" || instances4[1] != "host3" {
+		t.Fatalf("Unexpected instance(s): %s", instances4)
+	}
+}