libvirt/resource_libvirt_network: Support updates for dns.hosts

libvirt/network.go

@@ -0,0 +1,138 @@
+package libvirt
+
+import (
+	"errors"
+	"fmt"
+	"reflect"
+	"sort"
+
+	"github.com/hashicorp/terraform/helper/schema"
+	libvirt "github.com/libvirt/libvirt-go"
+	"github.com/libvirt/libvirt-go-xml"
+)
+
+func resourceLibvirtNetworkUpdateDNSHosts(d *schema.ResourceData, network *libvirt.Network) error {
+	hostsKey := dnsPrefix + ".hosts"
+	if d.HasChange(hostsKey) {
+		oldInterface, newInterface := d.GetChange(hostsKey)
+
+		oldEntries, err := parseNetworkDNSHostsChange(oldInterface)
+		if err != nil {
+			return fmt.Errorf("parse old %s: %s", hostsKey, err)
+		}
+
+		newEntries, err := parseNetworkDNSHostsChange(newInterface)
+		if err != nil {
+			return fmt.Errorf("parse new %s: %s", hostsKey, err)
+		}
+
+		for _, oldEntry := range oldEntries {
+			found := false
+			for _, newEntry := range newEntries {
+				if reflect.DeepEqual(newEntry, oldEntry) {
+					found = true
+					break
+				}
+			}
+			if found {
+				continue
+			}
+
+			data, err := xmlMarshallIndented(libvirtxml.NetworkDNSHost{IP: oldEntry.IP})
+			if err != nil {
+				return fmt.Errorf("serialize update: %s", err)
+			}
+
+			err = network.Update(libvirt.NETWORK_UPDATE_COMMAND_DELETE, libvirt.NETWORK_SECTION_DNS_HOST, -1, data, libvirt.NETWORK_UPDATE_AFFECT_LIVE|libvirt.NETWORK_UPDATE_AFFECT_CONFIG)
+			if err != nil {
+				return fmt.Errorf("delete %s: %s", oldEntry.IP, err)
+			}
+		}
+
+		for _, newEntry := range newEntries {
+			found := false
+			for _, oldEntry := range oldEntries {
+				if reflect.DeepEqual(oldEntry, newEntry) {
+					found = true
+					break
+				}
+			}
+			if found {
+				continue
+			}
+
+			data, err := xmlMarshallIndented(newEntry)
+			if err != nil {
+				return fmt.Errorf("serialize update: %s", err)
+			}
+
+			err = network.Update(libvirt.NETWORK_UPDATE_COMMAND_ADD_LAST, libvirt.NETWORK_SECTION_DNS_HOST, -1, data, libvirt.NETWORK_UPDATE_AFFECT_LIVE|libvirt.NETWORK_UPDATE_AFFECT_CONFIG)
+			if err != nil {
+				return fmt.Errorf("add %v: %s", newEntry, err)
+			}
+		}
+
+		d.SetPartial(hostsKey)
+	}
+
+	return nil
+}
+
+func parseNetworkDNSHostsChange(change interface{}) (entries []libvirtxml.NetworkDNSHost, err error) {
+	slice, ok := change.([]interface{})
+	if !ok {
+		return entries, errors.New("not slice")
+	}
+
+	mapEntries := map[string][]string{}
+	for i, entryInterface := range slice {
+		entryMap, ok := entryInterface.(map[string]interface{})
+		if !ok {
+			return nil, fmt.Errorf("entry %d is not a map", i)
+		}
+
+		ipInterface, ok := entryMap["ip"]
+		if !ok {
+			return nil, fmt.Errorf("entry %d.ip is missing", i)
+		}
+
+		ip, ok := ipInterface.(string)
+		if !ok {
+			return nil, fmt.Errorf("entry %d.ip is not a string", i)
+		}
+
+		hostnameInterface, ok := entryMap["hostname"]
+		if !ok {
+			return nil, fmt.Errorf("entry %d.hostname is missing", i)
+		}
+
+		hostname, ok := hostnameInterface.(string)
+		if !ok {
+			return nil, fmt.Errorf("entry %d.hostname is not a string", i)
+		}
+
+		_, ok = mapEntries[ip]
+		if ok {
+			mapEntries[ip] = append(mapEntries[ip], hostname)
+		} else {
+			mapEntries[ip] = []string{hostname}
+		}
+	}
+
+	entries = make([]libvirtxml.NetworkDNSHost, 0, len(mapEntries))
+	for ip, hostnames := range mapEntries {
+		sort.Strings(hostnames)
+		xmlHostnames := make([]libvirtxml.NetworkDNSHostHostname, 0, len(hostnames))
+		for _, hostname := range hostnames {
+			xmlHostnames = append(xmlHostnames, libvirtxml.NetworkDNSHostHostname{
+				Hostname: hostname,
+			})
+		}
+		entries = append(entries, libvirtxml.NetworkDNSHost{
+			IP:        ip,
+			Hostnames: xmlHostnames,
+		})
+	}
+
+	return entries, nil
+}

libvirt/resource_libvirt_network.go

@@ -170,7 +170,6 @@ func resourceLibvirtNetwork() *schema.Resource {
 						"hosts": {
 							Type:     schema.TypeList,
 							Optional: true,
-							ForceNew: true,
 							Elem: &schema.Resource{
 								Schema: map[string]*schema.Schema{
 									"ip": {
@@ -179,15 +178,13 @@ func resourceLibvirtNetwork() *schema.Resource {
 										// and therefore doesn't recognize that this is set when assigning from
 										// a rendered dns_host template.
 										Optional: true,
-										ForceNew: true,
 									},
 									"hostname": {
 										Type: schema.TypeString,
 										// This should be required, but Terraform does validation too early
 										// and therefore doesn't recognize that this is set when assigning from
 										// a rendered dns_host template.
 										Optional: true,
-										ForceNew: true,
 									},
 								},
 							},
@@ -266,6 +263,12 @@ func resourceLibvirtNetworkUpdate(d *schema.ResourceData, meta interface{}) erro
 		}
 		d.SetPartial("autostart")
 	}
+
+	err = resourceLibvirtNetworkUpdateDNSHosts(d, network)
+	if err != nil {
+		return fmt.Errorf("update DNS hosts: %s", err)
+	}
+
 	d.Partial(false)
 	return nil
 }

libvirt/resource_libvirt_network_test.go

@@ -201,6 +201,76 @@ func TestAccLibvirtNetwork_DNSHosts(t *testing.T) {
 					}),
 				),
 			},
+			{
+				Config: fmt.Sprintf(`
+				resource "libvirt_network" "%s" {
+					name      = "%s"
+					domain    = "k8s.local"
+					addresses = ["10.17.3.0/24"]
+					dns {
+						hosts = [
+						  {
+							  hostname = "myhost1",
+							  ip = "1.1.1.1",
+						  },
+						]
+					}
+				}`, randomNetworkResource, randomNetworkName),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.0.hostname", "myhost1"),
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.0.ip", "1.1.1.1"),
+					checkDNSHosts("libvirt_network."+randomNetworkResource, []libvirtxml.NetworkDNSHost{
+						{
+							IP: "1.1.1.1",
+							Hostnames: []libvirtxml.NetworkDNSHostHostname{
+								{Hostname: "myhost1"},
+							},
+						},
+					}),
+				),
+			},
+			{
+				Config: fmt.Sprintf(`
+				resource "libvirt_network" "%s" {
+					name      = "%s"
+					domain    = "k8s.local"
+					addresses = ["10.17.3.0/24"]
+					dns {
+						hosts = [
+						  {
+							  hostname = "myhost1",
+							  ip = "1.1.1.1",
+						  },
+# Without https:#www.redhat.com/archives/libvir-list/2018-November/msg00231.html, this raises:
+#
+#   update DNS hosts: add {{ } 1.1.1.2 [{myhost1}]}: virError(Code=55, Domain=19, Message='Requested operation is not valid: there is already at least one DNS HOST record with a matching field in network fo64d9y6w9')
+#						  {
+#							  hostname = "myhost1",
+#							  ip = "1.1.1.2",
+#						  },
+						  {
+							  hostname = "myhost2",
+							  ip = "1.1.1.1",
+						  },
+						]
+					}
+				}`, randomNetworkResource, randomNetworkName),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.0.hostname", "myhost1"),
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.0.ip", "1.1.1.1"),
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.1.hostname", "myhost2"),
+					resource.TestCheckResourceAttr("libvirt_network."+randomNetworkResource, "dns.0.hosts.1.ip", "1.1.1.1"),
+					checkDNSHosts("libvirt_network."+randomNetworkResource, []libvirtxml.NetworkDNSHost{
+						{
+							IP: "1.1.1.1",
+							Hostnames: []libvirtxml.NetworkDNSHostHostname{
+								{Hostname: "myhost1"},
+								{Hostname: "myhost2"},
+							},
+						},
+					}),
+				),
+			},
 		},
 	})
 }