Retry the query about interfaces to the qemu-agent

2 files changed, 81 insertions, 58 deletions

diff --git a/libvirt/qemu_agent.go b/libvirt/qemu_agent.go
index b884f7c4..fd7cef39 100644
--- a/libvirt/qemu_agent.go
+++ b/libvirt/qemu_agent.go
@@ -4,7 +4,9 @@ import (
 	"encoding/json"
 	"log"
 	"strings"
+	"time"
 
+	"github.com/hashicorp/terraform/helper/resource"
 	libvirt "github.com/libvirt/libvirt-go"
 )
 
@@ -27,75 +29,96 @@ type QemuAgentInterfaceIPAddress struct {
 	Prefix  uint   `json:"prefix"`
 }
 
-// Retrieve all the interfaces attached to a domain and their addresses. Only
-// the interfaces with at least an IP address are returned.
-// When wait4ipv4 is turned on the code will not report interfaces that don't
-// have a ipv4 address set. This is useful when a domain gets the ipv6 address
-// before the ipv4 one.
-func getDomainInterfacesViaQemuAgent(domain Domain, wait4ipv4 bool) []libvirt.DomainInterface {
-	log.Print("[DEBUG] get network interfaces using qemu agent")
+func qemuAgentInterfacesRefreshFunc(domain LibVirtDomain, wait4ipv4 bool) resource.StateRefreshFunc {
+	return func() (interface{}, string, error) {
 
-	var interfaces []libvirt.DomainInterface
+		var interfaces []libvirt.DomainInterface
 
-	result, err := domain.QemuAgentCommand(
-		"{\"execute\":\"guest-network-get-interfaces\"}",
-		libvirt.DOMAIN_QEMU_AGENT_COMMAND_DEFAULT,
-		0)
-	if err != nil {
-		return interfaces
-	}
-
-	log.Printf("[DEBUG] qemu-agent response: %s", result)
+		log.Printf("[DEBUG] sending command to qemu-agent in %s", domain)
+		result, err := domain.QemuAgentCommand(
+			"{\"execute\":\"guest-network-get-interfaces\"}",
+			libvirt.DOMAIN_QEMU_AGENT_COMMAND_DEFAULT,
+			0)
+		if err != nil {
+			log.Printf("[DEBUG] command error: %s", err)
+			return interfaces, "failed", nil
+		}
 
-	response := QemuAgentInterfacesResponse{}
-	if err := json.Unmarshal([]byte(result), &response); err != nil {
-		log.Printf("[DEBUG] Error converting Qemu agent response about domain interfaces: %s", err)
-		log.Printf("[DEBUG] Original message: %v", response)
-		log.Print("[DEBUG] Returning an empty list of interfaces")
-		return interfaces
-	}
-	log.Printf("[DEBUG] Parsed response %+v", response)
+		log.Printf("[DEBUG] qemu-agent response: %s", result)
 
-	for _, iface := range response.Interfaces {
-		if iface.Name == "lo" {
-			// ignore loopback interface
-			continue
+		response := QemuAgentInterfacesResponse{}
+		if err := json.Unmarshal([]byte(result), &response); err != nil {
+			log.Printf("[DEBUG] Error converting qemu-agent response about domain interfaces: %s", err)
+			log.Printf("[DEBUG] Original message: %s", response)
+			log.Print("[DEBUG] Returning an empty list of interfaces")
+			return interfaces, "fatal", nil
 		}
+		log.Printf("[DEBUG] Parsed response %+v", response)
 
-		libVirtIface := libvirt.DomainInterface{
-			Name:   iface.Name,
-			Hwaddr: iface.Hwaddr}
-
-		ipv4Assigned := false
-		for _, addr := range iface.IPAddresses {
-			if addr.Address == "" {
-				// ignore interfaces without an address (eg. waiting for dhcp lease)
+		for _, iface := range response.Interfaces {
+			if iface.Name == "lo" {
+				// ignore loopback interface
 				continue
 			}
 
-			libVirtAddr := libvirt.DomainIPAddress{
-				Addr:   addr.Address,
-				Prefix: addr.Prefix,
+			libVirtIface := libvirt.DomainInterface{
+				Name:   iface.Name,
+				Hwaddr: iface.Hwaddr}
+
+			ipv4Assigned := false
+			for _, addr := range iface.IpAddresses {
+				if addr.Address == "" {
+					// ignore interfaces without an address (eg. waiting for dhcp lease)
+					continue
+				}
+
+				libVirtAddr := libvirt.DomainIPAddress{
+					Addr:   addr.Address,
+					Prefix: addr.Prefix,
+				}
+
+				switch strings.ToLower(addr.Type) {
+				case "ipv4":
+					libVirtAddr.Type = int(libvirt.IP_ADDR_TYPE_IPV4)
+					ipv4Assigned = true
+				case "ipv6":
+					libVirtAddr.Type = int(libvirt.IP_ADDR_TYPE_IPV6)
+				default:
+					log.Printf("[ERROR] Cannot handle unknown address type %s", addr.Type)
+					continue
+				}
+				libVirtIface.Addrs = append(libVirtIface.Addrs, libVirtAddr)
 			}
-
-			switch strings.ToLower(addr.Type) {
-			case "ipv4":
-				libVirtAddr.Type = int(libvirt.IP_ADDR_TYPE_IPV4)
-				ipv4Assigned = true
-			case "ipv6":
-				libVirtAddr.Type = int(libvirt.IP_ADDR_TYPE_IPV6)
-			default:
-				log.Printf("[ERROR] Cannot handle unknown address type %s", addr.Type)
-				continue
+			if len(libVirtIface.Addrs) > 0 && (ipv4Assigned || !wait4ipv4) {
+				interfaces = append(interfaces, libVirtIface)
 			}
-			libVirtIface.Addrs = append(libVirtIface.Addrs, libVirtAddr)
-		}
-		if len(libVirtIface.Addrs) > 0 && (ipv4Assigned || !wait4ipv4) {
-			interfaces = append(interfaces, libVirtIface)
 		}
+
+		log.Printf("[DEBUG] Interfaces obtained via qemu-agent: %+v", interfaces)
+		return interfaces, "success", nil
+	}
+}
+
+// Retrieve all the interfaces attached to a domain and their addresses. Only
+// the interfaces with at least an IP address are returned.
+// When wait4ipv4 is turned on the code will not report interfaces that don't
+// have a ipv4 address set. This is useful when a domain gets the ipv6 address
+// before the ipv4 one.
+func getDomainInterfacesViaQemuAgent(domain LibVirtDomain, wait4ipv4 bool) []libvirt.DomainInterface {
+
+	qemuAgentQuery := &resource.StateChangeConf{
+		Pending:    []string{"failed"},
+		Target:     []string{"success"},
+		Refresh:    qemuAgentInterfacesRefreshFunc(domain, wait4ipv4),
+		MinTimeout: 4 * time.Second,
+		Delay:      4 * time.Second, // Wait this time before starting checks
+		Timeout:    16 * time.Second,
 	}
 
-	log.Printf("[DEBUG] Interfaces obtained via qemu Agent: %+v", interfaces)
+	interfaces, err := qemuAgentQuery.WaitForState()
+	if err != nil {
+		return []libvirt.DomainInterface{}
+	}
 
-	return interfaces
+	return interfaces.([]libvirt.DomainInterface)
 }
diff --git a/libvirt/resource_libvirt_domain.go b/libvirt/resource_libvirt_domain.go
index b5d0fb6d..25829f35 100644
--- a/libvirt/resource_libvirt_domain.go
+++ b/libvirt/resource_libvirt_domain.go
@@ -1300,6 +1300,7 @@ func getDomainInterfaces(domain libvirt.Domain) ([]libvirt.DomainInterface, erro
 	// get all the interfaces using the qemu-agent, this includes also
 	// interfaces that are not attached to networks managed by libvirt
 	// (eg. bridges, macvtap,...)
+	log.Print("[DEBUG] fetching networking interfaces using qemu-agent")
 	interfaces := getDomainInterfacesViaQemuAgent(&domain, true)
 	if len(interfaces) > 0 {
 		// the agent will always return all the interfaces, both the
@@ -1308,9 +1309,8 @@ func getDomainInterfaces(domain libvirt.Domain) ([]libvirt.DomainInterface, erro
 		return interfaces, nil
 	}
 
-	log.Print("[DEBUG] fetching networking interfaces using libvirt API")
-
 	// get all the interfaces attached to libvirt networks
+	log.Print("[DEBUG] fetching networking interfaces using libvirt API")
 	interfaces, err := domain.ListAllInterfaceAddresses(libvirt.DOMAIN_INTERFACE_ADDRESSES_SRC_LEASE)
 	if err != nil {
 		switch err.(type) {