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libvirt.go
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libvirt.go
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// Copyright 2018 The go-libvirt Authors.
//
// 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 libvirt
// We'll use c-for-go to extract the consts and typedefs from the libvirt
// sources so we don't have to duplicate them here.
//go:generate scripts/gen-consts.sh
import (
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"net"
"sync"
"syscall"
"time"
"github.com/digitalocean/go-libvirt/internal/constants"
"github.com/digitalocean/go-libvirt/internal/event"
xdr "github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2"
"github.com/digitalocean/go-libvirt/socket"
"github.com/digitalocean/go-libvirt/socket/dialers"
)
// ErrEventsNotSupported is returned by Events() if event streams
// are unsupported by either QEMU or libvirt.
var ErrEventsNotSupported = errors.New("event monitor is not supported")
// ConnectURI defines a type for driver URIs for libvirt
// the defined constants are *not* exhaustive as there are also options
// e.g. to connect remote via SSH
type ConnectURI string
const (
// QEMUSystem connects to a QEMU system mode daemon
QEMUSystem ConnectURI = "qemu:///system"
// QEMUSession connects to a QEMU session mode daemon (unprivileged)
QEMUSession ConnectURI = "qemu:///session"
// XenSystem connects to a Xen system mode daemon
XenSystem ConnectURI = "xen:///system"
//TestDefault connect to default mock driver
TestDefault ConnectURI = "test:///default"
// disconnectedTimeout is how long to wait for disconnect cleanup to
// complete
disconnectTimeout = 5 * time.Second
)
// Libvirt implements libvirt's remote procedure call protocol.
type Libvirt struct {
// socket connection
socket *socket.Socket
// closed after cleanup complete following the underlying connection to
// libvirt being disconnected.
disconnected chan struct{}
// method callbacks
cmux sync.RWMutex
callbacks map[int32]chan response
// event listeners
emux sync.RWMutex
events map[int32]*event.Stream
// next request serial number
s int32
}
// DomainEvent represents a libvirt domain event.
type DomainEvent struct {
CallbackID int32
Domain Domain
Event string
Seconds uint64
Microseconds uint32
Padding uint8
Details []byte
}
// GetCallbackID returns the callback ID of a QEMU domain event.
func (de DomainEvent) GetCallbackID() int32 {
return de.CallbackID
}
// GetCallbackID returns the callback ID of a libvirt lifecycle event.
func (m DomainEventCallbackLifecycleMsg) GetCallbackID() int32 {
return m.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackRebootMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackRtcChangeMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackWatchdogMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackIOErrorMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackIOErrorReasonMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackGraphicsMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackBlockJobMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackDiskChangeMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackTrayChangeMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackPmwakeupMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackPmsuspendMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackBalloonChangeMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackPmsuspendDiskMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackControlErrorMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackDeviceRemovedMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackTunableMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackDeviceAddedMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackAgentLifecycleMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackMigrationIterationMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackJobCompletedMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackDeviceRemovalFailedMsg) GetCallbackID() int32 {
return e.CallbackID
}
// GetCallbackID returns the callback ID.
func (e *DomainEventCallbackMetadataChangeMsg) GetCallbackID() int32 {
return e.CallbackID
}
// qemuError represents a QEMU process error.
type qemuError struct {
Error struct {
Class string `json:"class"`
Description string `json:"desc"`
} `json:"error"`
}
// Capabilities returns an XML document describing the host's capabilties.
func (l *Libvirt) Capabilities() ([]byte, error) {
caps, err := l.ConnectGetCapabilities()
return []byte(caps), err
}
// called at connection time, authenticating with all supported auth types
func (l *Libvirt) authenticate() error {
// libvirt requires that we call auth-list prior to connecting,
// even when no authentication is used.
resp, err := l.AuthList()
if err != nil {
return err
}
for _, auth := range resp {
switch auth {
case constants.AuthNone:
case constants.AuthPolkit:
_, err := l.AuthPolkit()
if err != nil {
return err
}
default:
continue
}
break
}
return nil
}
func (l *Libvirt) initLibvirtComms(uri ConnectURI) error {
payload := struct {
Padding [3]byte
Name string
Flags uint32
}{
Padding: [3]byte{0x1, 0x0, 0x0},
Name: string(uri),
Flags: 0,
}
buf, err := encode(&payload)
if err != nil {
return err
}
err = l.authenticate()
if err != nil {
return err
}
_, err = l.request(constants.ProcConnectOpen, constants.Program, buf)
if err != nil {
return err
}
return nil
}
// ConnectToURI establishes communication with the specified libvirt driver
// The underlying libvirt socket connection will be created via the dialer.
// Since the connection can be lost, the Disconnected function can be used
// to monitor for a lost connection.
func (l *Libvirt) ConnectToURI(uri ConnectURI) error {
err := l.socket.Connect()
if err != nil {
return err
}
// Start watching the underlying socket connection immediately.
// If we don't, and Libvirt goes away partway through initLibvirtComms,
// then the callbacks that initLibvirtComms has registered will never
// be closed, and therefore it will be stuck waiting for data from a
// channel that will never arrive.
go l.waitAndDisconnect()
err = l.initLibvirtComms(uri)
if err != nil {
l.socket.Disconnect()
return err
}
l.disconnected = make(chan struct{})
return nil
}
// Connect establishes communication with the libvirt server.
// The underlying libvirt socket connection will be created via the dialer.
// Since the connection can be lost, the Disconnected function can be used
// to monitor for a lost connection.
func (l *Libvirt) Connect() error {
return l.ConnectToURI(QEMUSystem)
}
// Disconnect shuts down communication with the libvirt server and closes the
// underlying net.Conn.
func (l *Libvirt) Disconnect() error {
// Ordering is important here. We want to make sure the connection is closed
// before unsubscribing and deregistering the events and requests, to
// prevent new requests from racing.
_, err := l.request(constants.ProcConnectClose, constants.Program, nil)
// syscall.EINVAL is returned by the socket pkg when things have already
// been disconnected.
if err != nil && err != syscall.EINVAL {
return err
}
err = l.socket.Disconnect()
if err != nil {
return err
}
// wait for the listen goroutine to detect the lost connection and clean up
// to happen once it returns. Safeguard with a timeout.
// Things not fully cleaned up is better than a deadlock.
select {
case <-l.disconnected:
case <-time.After(disconnectTimeout):
}
return err
}
// Disconnected allows callers to detect if the underlying connection
// to libvirt has been closed. If the returned channel is closed, then
// the connection to libvirt has been lost (or disconnected intentionally).
func (l *Libvirt) Disconnected() <-chan struct{} {
return l.disconnected
}
// IsConnected indicates whether or not there is currently a connection to
// libvirtd.
func (l *Libvirt) IsConnected() bool {
select {
case <-l.Disconnected():
return false
default:
return true
}
}
// Domains returns a list of all domains managed by libvirt.
//
// Deprecated: use ConnectListAllDomains instead.
func (l *Libvirt) Domains() ([]Domain, error) {
// these are the flags as passed by `virsh list --all`
flags := ConnectListDomainsActive | ConnectListDomainsInactive
domains, _, err := l.ConnectListAllDomains(1, flags)
return domains, err
}
// DomainState returns state of the domain managed by libvirt.
//
// Deprecated: use DomainGetState instead.
func (l *Libvirt) DomainState(dom string) (DomainState, error) {
d, err := l.lookup(dom)
if err != nil {
return DomainNostate, err
}
state, _, err := l.DomainGetState(d, 0)
return DomainState(state), err
}
// SubscribeQEMUEvents streams domain events until the provided context is
// cancelled. If a problem is encountered setting up the event monitor
// connection an error will be returned. Errors encountered during streaming
// will cause the returned event channel to be closed. QEMU domain events.
func (l *Libvirt) SubscribeQEMUEvents(ctx context.Context, dom string) (<-chan DomainEvent, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
callbackID, err := l.QEMUConnectDomainMonitorEventRegister([]Domain{d}, nil, 0)
if err != nil {
return nil, err
}
stream := event.NewStream(constants.QEMUProgram, callbackID)
l.addStream(stream)
ch := make(chan DomainEvent)
go func() {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
defer l.unsubscribeQEMUEvents(stream)
defer stream.Shutdown()
defer close(ch)
for {
select {
case ev, ok := <-stream.Recv():
if !ok {
return
}
ch <- *ev.(*DomainEvent)
case <-ctx.Done():
return
}
}
}()
return ch, nil
}
// unsubscribeQEMUEvents stops the flow of events from QEMU through libvirt.
func (l *Libvirt) unsubscribeQEMUEvents(stream *event.Stream) error {
err := l.QEMUConnectDomainMonitorEventDeregister(stream.CallbackID)
l.removeStream(stream.CallbackID)
return err
}
// SubscribeEvents allows the caller to subscribe to any of the event types
// supported by libvirt. The events will continue to be streamed until the
// caller cancels the provided context. After canceling the context, callers
// should wait until the channel is closed to be sure they're collected all the
// events.
func (l *Libvirt) SubscribeEvents(ctx context.Context, eventID DomainEventID,
dom OptDomain) (<-chan interface{}, error) {
callbackID, err := l.ConnectDomainEventCallbackRegisterAny(int32(eventID), nil)
if err != nil {
return nil, err
}
stream := event.NewStream(constants.QEMUProgram, callbackID)
l.addStream(stream)
ch := make(chan interface{})
go func() {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
defer l.unsubscribeEvents(stream)
defer stream.Shutdown()
defer func() { close(ch) }()
for {
select {
case ev, ok := <-stream.Recv():
if !ok {
return
}
ch <- ev
case <-ctx.Done():
return
}
}
}()
return ch, nil
}
// unsubscribeEvents stops the flow of the specified events from libvirt. There
// are two steps to this process: a call to libvirt to deregister our callback,
// and then removing the callback from the list used by the `Route` function. If
// the deregister call fails, we'll return the error, but still remove the
// callback from the list. That's ok; if any events arrive after this point, the
// Route function will drop them when it finds no registered handler.
func (l *Libvirt) unsubscribeEvents(stream *event.Stream) error {
err := l.ConnectDomainEventCallbackDeregisterAny(stream.CallbackID)
l.removeStream(stream.CallbackID)
return err
}
// LifecycleEvents streams lifecycle events until the provided context is
// cancelled. If a problem is encountered setting up the event monitor
// connection, an error will be returned. Errors encountered during streaming
// will cause the returned event channel to be closed.
func (l *Libvirt) LifecycleEvents(ctx context.Context) (<-chan DomainEventLifecycleMsg, error) {
callbackID, err := l.ConnectDomainEventCallbackRegisterAny(int32(DomainEventIDLifecycle), nil)
if err != nil {
return nil, err
}
stream := event.NewStream(constants.Program, callbackID)
l.addStream(stream)
ch := make(chan DomainEventLifecycleMsg)
go func() {
ctx, cancel := context.WithCancel(ctx)
defer cancel()
defer l.unsubscribeEvents(stream)
defer stream.Shutdown()
defer func() { close(ch) }()
for {
select {
case ev, ok := <-stream.Recv():
if !ok {
return
}
ch <- ev.(*DomainEventCallbackLifecycleMsg).Msg
case <-ctx.Done():
return
}
}
}()
return ch, nil
}
// Run executes the given QAPI command against a domain's QEMU instance.
// For a list of available QAPI commands, see:
// http://git.qemu.org/?p=qemu.git;a=blob;f=qapi-schema.json;hb=HEAD
func (l *Libvirt) Run(dom string, cmd []byte) ([]byte, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
payload := struct {
Domain Domain
Command []byte
Flags uint32
}{
Domain: d,
Command: cmd,
Flags: 0,
}
buf, err := encode(&payload)
if err != nil {
return nil, err
}
res, err := l.request(constants.QEMUProcDomainMonitorCommand, constants.QEMUProgram, buf)
if err != nil {
return nil, err
}
// check for QEMU process errors
if err = getQEMUError(res); err != nil {
return nil, err
}
r := bytes.NewReader(res.Payload)
dec := xdr.NewDecoder(r)
data, _, err := dec.DecodeFixedOpaque(int32(r.Len()))
if err != nil {
return nil, err
}
// drop QMP control characters from start of line, and drop
// any trailing NULL characters from the end
return bytes.TrimRight(data[4:], "\x00"), nil
}
// Secrets returns all secrets managed by the libvirt daemon.
//
// Deprecated: use ConnectListAllSecrets instead.
func (l *Libvirt) Secrets() ([]Secret, error) {
secrets, _, err := l.ConnectListAllSecrets(1, 0)
return secrets, err
}
// StoragePool returns the storage pool associated with the provided name.
// An error is returned if the requested storage pool is not found.
//
// Deprecated: use StoragePoolLookupByName instead.
func (l *Libvirt) StoragePool(name string) (StoragePool, error) {
return l.StoragePoolLookupByName(name)
}
// StoragePools returns a list of defined storage pools. Pools are filtered by
// the provided flags. See StoragePools*.
//
// Deprecated: use ConnectListAllStoragePools instead.
func (l *Libvirt) StoragePools(flags ConnectListAllStoragePoolsFlags) ([]StoragePool, error) {
pools, _, err := l.ConnectListAllStoragePools(1, flags)
return pools, err
}
// Undefine undefines the domain specified by dom, e.g., 'prod-lb-01'.
// The flags argument allows additional options to be specified such as
// cleaning up snapshot metadata. For more information on available
// flags, see DomainUndefine*.
//
// Deprecated: use DomainUndefineFlags instead.
func (l *Libvirt) Undefine(dom string, flags DomainUndefineFlagsValues) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
return l.DomainUndefineFlags(d, flags)
}
// Destroy destroys the domain specified by dom, e.g., 'prod-lb-01'.
// The flags argument allows additional options to be specified such as
// allowing a graceful shutdown with SIGTERM than SIGKILL.
// For more information on available flags, see DomainDestroy*.
//
// Deprecated: use DomainDestroyFlags instead.
func (l *Libvirt) Destroy(dom string, flags DomainDestroyFlagsValues) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
return l.DomainDestroyFlags(d, flags)
}
// XML returns a domain's raw XML definition, akin to `virsh dumpxml <domain>`.
// See DomainXMLFlag* for optional flags.
//
// Deprecated: use DomainGetXMLDesc instead.
func (l *Libvirt) XML(dom string, flags DomainXMLFlags) ([]byte, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
xml, err := l.DomainGetXMLDesc(d, flags)
return []byte(xml), err
}
// DefineXML defines a domain, but does not start it.
//
// Deprecated: use DomainDefineXMLFlags instead.
func (l *Libvirt) DefineXML(x []byte, flags DomainDefineFlags) error {
_, err := l.DomainDefineXMLFlags(string(x), flags)
return err
}
// Version returns the version of the libvirt daemon.
//
// Deprecated: use ConnectGetLibVersion instead.
func (l *Libvirt) Version() (string, error) {
ver, err := l.ConnectGetLibVersion()
if err != nil {
return "", err
}
// The version is provided as an int following this formula:
// version * 1,000,000 + minor * 1000 + micro
// See src/libvirt-host.c # virConnectGetLibVersion
major := ver / 1000000
ver %= 1000000
minor := ver / 1000
ver %= 1000
micro := ver
versionString := fmt.Sprintf("%d.%d.%d", major, minor, micro)
return versionString, nil
}
// Shutdown shuts down a domain. Note that the guest OS may ignore the request.
// If flags is set to 0 then the hypervisor will choose the method of shutdown it considers best.
//
// Deprecated: use DomainShutdownFlags instead.
func (l *Libvirt) Shutdown(dom string, flags DomainShutdownFlagValues) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
return l.DomainShutdownFlags(d, flags)
}
// Reboot reboots the domain. Note that the guest OS may ignore the request.
// If flags is set to zero, then the hypervisor will choose the method of shutdown it considers best.
//
// Deprecated: use DomainReboot instead.
func (l *Libvirt) Reboot(dom string, flags DomainRebootFlagValues) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
return l.DomainReboot(d, flags)
}
// Reset resets domain immediately without any guest OS shutdown
//
// Deprecated: use DomainReset instead.
func (l *Libvirt) Reset(dom string) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
return l.DomainReset(d, 0)
}
// BlockLimit contains a name and value pair for a Get/SetBlockIOTune limit. The
// Name field is the name of the limit (to see a list of the limits that can be
// applied, execute the 'blkdeviotune' command on a VM in virsh). Callers can
// use the QEMUBlockIO... constants below for the Name value. The Value field is
// the limit to apply.
type BlockLimit struct {
Name string
Value uint64
}
// SetBlockIOTune changes the per-device block I/O tunables within a guest.
// Parameters are the name of the VM, the name of the disk device to which the
// limits should be applied, and 1 or more BlockLimit structs containing the
// actual limits.
//
// The limits which can be applied here are enumerated in the QEMUBlockIO...
// constants above, and you can also see the full list by executing the
// 'blkdeviotune' command on a VM in virsh.
//
// Example usage:
// SetBlockIOTune("vm-name", "vda", BlockLimit{libvirt.QEMUBlockIOWriteBytesSec, 1000000})
//
// Deprecated: use DomainSetBlockIOTune instead.
func (l *Libvirt) SetBlockIOTune(dom string, disk string, limits ...BlockLimit) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
params := make([]TypedParam, len(limits))
for ix, limit := range limits {
tpval := NewTypedParamValueUllong(limit.Value)
params[ix] = TypedParam{Field: limit.Name, Value: *tpval}
}
return l.DomainSetBlockIOTune(d, disk, params, uint32(DomainAffectLive))
}
// GetBlockIOTune returns a slice containing the current block I/O tunables for
// a disk.
//
// Deprecated: use DomainGetBlockIOTune instead.
func (l *Libvirt) GetBlockIOTune(dom string, disk string) ([]BlockLimit, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
lims, _, err := l.DomainGetBlockIOTune(d, []string{disk}, 32, uint32(TypedParamStringOkay))
if err != nil {
return nil, err
}
var limits []BlockLimit
// now decode each of the returned TypedParams. To do this we read the field
// name and type, then use the type information to decode the value.
for _, lim := range lims {
var l BlockLimit
name := lim.Field
switch lim.Value.I.(type) {
case uint64:
l = BlockLimit{Name: name, Value: lim.Value.I.(uint64)}
}
limits = append(limits, l)
}
return limits, nil
}
// lookup returns a domain as seen by libvirt.
func (l *Libvirt) lookup(name string) (Domain, error) {
return l.DomainLookupByName(name)
}
// getQEMUError checks the provided response for QEMU process errors.
// If an error is found, it is extracted an returned, otherwise nil.
func getQEMUError(r response) error {
pl := bytes.NewReader(r.Payload)
dec := xdr.NewDecoder(pl)
s, _, err := dec.DecodeString()
if err != nil {
return err
}
var e qemuError
if err = json.Unmarshal([]byte(s), &e); err != nil {
return err
}
if e.Error.Description != "" {
return errors.New(e.Error.Description)
}
return nil
}
func (l *Libvirt) waitAndDisconnect() {
// wait for the socket to indicate if/when it's been disconnected
<-l.socket.Disconnected()
// close event streams
l.removeAllStreams()
// Deregister all callbacks to prevent blocking on clients with
// outstanding requests
l.deregisterAll()
select {
case <-l.disconnected:
// l.disconnected is already closed, i.e., Libvirt.ConnectToURI
// was unable to complete all phases of its connection and
// so this hadn't been assigned to an open channel yet (it
// is set to a closed channel in Libvirt.New*)
//
// Just return to avoid closing an already-closed channel.
return
default:
// if we make it here then reading from l.disconnected is blocking,
// which suggests that it is open and must be closed.
}
close(l.disconnected)
}
// NewWithDialer configures a new Libvirt object that can be used to perform
// RPCs via libvirt's socket. The actual connection will not be established
// until Connect is called. The same Libvirt object may be used to re-connect
// multiple times.
func NewWithDialer(dialer socket.Dialer) *Libvirt {
l := &Libvirt{
s: 0,
disconnected: make(chan struct{}),
callbacks: make(map[int32]chan response),
events: make(map[int32]*event.Stream),
}
l.socket = socket.New(dialer, l)
// we start with a closed channel since that indicates no connection
close(l.disconnected)
return l
}
// New configures a new Libvirt RPC connection.
// This function only remains to retain backwards compatability.
// When Libvirt's Connect function is called, the Dial will simply return the
// connection passed in here and start a goroutine listening/reading from it.
// If at any point the Disconnect function is called, any subsequent Connect
// call will simply return an already closed connection.
//
// Deprecated: Please use NewWithDialer.
func New(conn net.Conn) *Libvirt {
return NewWithDialer(dialers.NewAlreadyConnected(conn))
}
// NetworkUpdateCompat is a wrapper over NetworkUpdate which swaps `Command` and `Section` when needed.
// This function must be used instead of NetworkUpdate to be sure that the
// NetworkUpdate call works both with older and newer libvirtd connections.
//
// libvirt on-wire protocol had a bug for a long time where Command and Section
// were reversed. It's been fixed in newer libvirt versions, and backported to
// some older versions. This helper detects what argument order libvirtd expects
// and makes the correct NetworkUpdate call.
func (l *Libvirt) NetworkUpdateCompat(Net Network, Command NetworkUpdateCommand, Section NetworkUpdateSection, ParentIndex int32, XML string, Flags NetworkUpdateFlags) (err error) {
// This is defined in libvirt/src/libvirt_internal.h and thus not available in go-libvirt autogenerated code
const virDrvFeatureNetworkUpdateHasCorrectOrder = 16
hasCorrectOrder, err := l.ConnectSupportsFeature(virDrvFeatureNetworkUpdateHasCorrectOrder)
if err != nil {
return fmt.Errorf("failed to confirm argument order for NetworkUpdate: %w", err)
}
// https://gitlab.com/libvirt/libvirt/-/commit/b0f78d626a18bcecae3a4d165540ab88bfbfc9ee
if hasCorrectOrder == 0 {
return l.NetworkUpdate(Net, uint32(Section), uint32(Command), ParentIndex, XML, Flags)
}
return l.NetworkUpdate(Net, uint32(Command), uint32(Section), ParentIndex, XML, Flags)
}