go-libvirt-plain/libvirt.go
Alexander Polakov 208ef2aff1 Add Shutdown() method (#36)
* Add Shutdown() method
2017-05-04 10:39:45 -05:00

1093 lines
24 KiB
Go

// Copyright 2016 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 is a pure Go implementation of the libvirt RPC protocol.
// For more information on the protocol, see https://libvirt.org/internals/l.html
package libvirt
import (
"bufio"
"bytes"
"encoding/json"
"errors"
"fmt"
"net"
"net/url"
"sync"
"github.com/davecgh/go-xdr/xdr2"
"github.com/digitalocean/go-libvirt/internal/constants"
)
// ErrEventsNotSupported is returned by Events() if event streams
// are unsupported by either QEMU or libvirt.
var ErrEventsNotSupported = errors.New("event monitor is not supported")
// Libvirt implements LibVirt's remote procedure call protocol.
type Libvirt struct {
conn net.Conn
r *bufio.Reader
w *bufio.Writer
// method callbacks
cm sync.Mutex
callbacks map[uint32]chan response
// event listeners
em sync.Mutex
events map[uint32]chan *DomainEvent
// next request serial number
s uint32
}
// Domain represents a domain as seen by libvirt.
type Domain struct {
Name string
UUID [constants.UUIDSize]byte
ID int
}
// DomainEvent represents a libvirt domain event.
type DomainEvent struct {
CallbackID uint32
Domain Domain
Event string
Seconds uint64
Microseconds uint32
Padding uint8
Details []byte
}
// Secret represents a secret managed by the libvirt daemon.
type Secret struct {
UUID [constants.UUIDSize]byte
UsageType SecretUsageType
UsageID string
}
// StoragePool represents a storage pool as seen by libvirt.
type StoragePool struct {
Name string
UUID [constants.UUIDSize]byte
}
// qemuError represents a QEMU process error.
type qemuError struct {
Error struct {
Class string `json:"class"`
Description string `json:"desc"`
} `json:"error"`
}
// DomainXMLFlags specifies options for dumping a domain's XML.
type DomainXMLFlags uint32
const (
// DomainXMLFlagSecure dumps XML with sensitive information included.
DomainXMLFlagSecure DomainXMLFlags = 1 << iota
// DomainXMLFlagInactive dumps XML with inactive domain information.
DomainXMLFlagInactive
// DomainXMLFlagUpdateCPU dumps XML with guest CPU requirements according to the host CPU.
DomainXMLFlagUpdateCPU
// DomainXMLFlagMigratable dumps XML suitable for migration.
DomainXMLFlagMigratable
)
// MigrateFlags specifies options when performing a migration.
type MigrateFlags uint32
const (
// MigrateFlagLive performs a zero-downtime live migration.
MigrateFlagLive MigrateFlags = 1 << iota
// MigrateFlagPeerToPeer creates a direct source to destination control channel.
MigrateFlagPeerToPeer
// MigrateFlagTunneled tunnels migration data over the libvirtd connection.
MigrateFlagTunneled
// MigrateFlagPersistDestination will persist the VM on the destination host.
MigrateFlagPersistDestination
// MigrateFlagUndefineSource undefines the VM on the source host.
MigrateFlagUndefineSource
// MigrateFlagPaused will pause the remote side VM.
MigrateFlagPaused
// MigrateFlagNonSharedDisk migrate non-shared storage with full disk copy.
MigrateFlagNonSharedDisk
// MigrateFlagNonSharedIncremental migrate non-shared storage with incremental copy.
MigrateFlagNonSharedIncremental
// MigrateFlagChangeProtection prevents any changes to the domain configuration through the whole migration process.
MigrateFlagChangeProtection
// MigrateFlagUnsafe will force a migration even when it is considered unsafe.
MigrateFlagUnsafe
// MigrateFlagOffline is used to perform an offline migration.
MigrateFlagOffline
// MigrateFlagCompressed compresses data during migration.
MigrateFlagCompressed
// MigrateFlagAbortOnError will abort a migration on I/O errors encountered during migration.
MigrateFlagAbortOnError
// MigrateFlagAutoConverge forces convergence.
MigrateFlagAutoConverge
// MigrateFlagRDMAPinAll enables RDMA memory pinning.
MigrateFlagRDMAPinAll
)
// UndefineFlags specifies options available when undefining a domain.
type UndefineFlags uint32
const (
// UndefineFlagManagedSave removes all domain managed save data.
UndefineFlagManagedSave UndefineFlags = 1 << iota
// UndefineFlagSnapshotsMetadata removes all domain snapshot metadata.
UndefineFlagSnapshotsMetadata
// UndefineFlagNVRAM removes all domain NVRAM files.
UndefineFlagNVRAM
)
// DomainDefineXMLFlags specifies options available when defining a domain.
type DomainDefineXMLFlags uint32
const (
// DefineValidate validates the XML document against schema
DefineValidate DomainDefineXMLFlags = 1
)
// DestroyFlags specifies options available when destroying a domain.
type DestroyFlags uint32
const (
// DestroyFlagDefault default behavior, forcefully terminate the domain.
DestroyFlagDefault DestroyFlags = 1 << iota
// DestroyFlagGraceful only sends a SIGTERM no SIGKILL.
DestroyFlagGraceful
)
// ShutdownFlags specifies options available when shutting down a domain.
type ShutdownFlags uint32
const (
// ShutdownAcpiPowerBtn - send ACPI event
ShutdownAcpiPowerBtn ShutdownFlags = 1 << iota
// ShutdownGuestAgent - use guest agent
ShutdownGuestAgent
// ShutdownInitctl - use initctl
ShutdownInitctl
// ShutdownSignal - use signal
ShutdownSignal
// ShutdownParavirt - use paravirt guest control
ShutdownParavirt
)
// DomainState specifies state of the domain
type DomainState uint32
const (
// DomainStateNoState No state
DomainStateNoState = iota
// DomainStateRunning The domain is running
DomainStateRunning
// DomainStateBlocked The domain is blocked on resource
DomainStateBlocked
// DomainStatePaused The domain is paused by user
DomainStatePaused
// DomainStateShutdown The domain is being shut down
DomainStateShutdown
// DomainStateShutoff The domain is shut off
DomainStateShutoff
// DomainStateCrashed The domain is crashed
DomainStateCrashed
// DomainStatePMSuspended The domain is suspended by guest power management
DomainStatePMSuspended
// DomainStateLast This value will increase over time as new events are added to the libvirt
// API. It reflects the last state supported by this version of the libvirt API.
DomainStateLast
)
// SecretUsageType specifies the usage for a libvirt secret.
type SecretUsageType uint32
const (
// SecretUsageTypeNone specifies no usage.
SecretUsageTypeNone SecretUsageType = iota
// SecretUsageTypeVolume specifies a volume secret.
SecretUsageTypeVolume
// SecretUsageTypeCeph specifies secrets for ceph devices.
SecretUsageTypeCeph
// SecretUsageTypeISCSI specifies secrets for ISCSI devices.
SecretUsageTypeISCSI
)
// StoragePoolsFlags specifies storage pools to list.
type StoragePoolsFlags uint32
// These flags come in groups; if all bits from a group are 0,
// then that group is not used to filter results.
const (
StoragePoolsFlagInactive = 1 << iota
StoragePoolsFlagActive
StoragePoolsFlagPersistent
StoragePoolsFlagTransient
StoragePoolsFlagAutostart
StoragePoolsFlagNoAutostart
// pools by type
StoragePoolsFlagDir
StoragePoolsFlagFS
StoragePoolsFlagNETFS
StoragePoolsFlagLogical
StoragePoolsFlagDisk
StoragePoolsFlagISCSI
StoragePoolsFlagSCSI
StoragePoolsFlagMPATH
StoragePoolsFlagRBD
StoragePoolsFlagSheepdog
StoragePoolsFlagGluster
StoragePoolsFlagZFS
)
// DomainCreateFlags specify options for starting domains
type DomainCreateFlags uint32
const (
// DomainCreateFlagPaused creates paused domain.
DomainCreateFlagPaused = 1 << iota
// DomainCreateFlagAutoDestroy destoy domain after libvirt connection closed.
DomainCreateFlagAutoDestroy
// DomainCreateFlagBypassCache avoid file system cache pollution.
DomainCreateFlagBypassCache
// DomainCreateFlagStartForceBoot boot, discarding any managed save
DomainCreateFlagStartForceBoot
// DomainCreateFlagStartValidate validate the XML document against schema
DomainCreateFlagStartValidate
)
// Capabilities returns an XML document describing the host's capabilties.
func (l *Libvirt) Capabilities() ([]byte, error) {
resp, err := l.request(constants.ProcConnectGetCapabilties, constants.ProgramRemote, nil)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
caps, _, err := dec.DecodeString()
return []byte(caps), err
}
// Connect establishes communication with the libvirt server.
// The underlying libvirt socket connection must be previously established.
func (l *Libvirt) Connect() error {
return l.connect()
}
// Disconnect shuts down communication with the libvirt server
// and closes the underlying net.Conn.
func (l *Libvirt) Disconnect() error {
// close event streams
for id := range l.events {
if err := l.removeStream(id); err != nil {
return err
}
}
// inform libvirt we're done
if err := l.disconnect(); err != nil {
return err
}
return l.conn.Close()
}
// Domains returns a list of all domains managed by libvirt.
func (l *Libvirt) Domains() ([]Domain, error) {
// these are the flags as passed by `virsh`, defined in:
// src/remote/remote_protocol.x # remote_connect_list_all_domains_args
req := struct {
NeedResults uint32
Flags uint32
}{
NeedResults: 1,
Flags: 3,
}
buf, err := encode(&req)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcConnectListAllDomains, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
result := struct {
Domains []Domain
Count uint32
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
if err != nil {
return nil, err
}
return result.Domains, nil
}
// DomainCreateWithFlags starts specified domain with flags
func (l *Libvirt) DomainCreateWithFlags(dom string, flags DomainCreateFlags) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
req := struct {
Domain Domain
Flags DomainCreateFlags
} {
Domain: *d,
Flags: flags,
}
buf, err := encode(&req)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainCreateWithFlags, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// DomainState returns state of the domain managed by libvirt.
func (l *Libvirt) DomainState(dom string) (DomainState, error) {
d, err := l.lookup(dom)
if err != nil {
return DomainStateNoState, err
}
req := struct {
Domain Domain
Flags uint32
}{
Domain: *d,
Flags: 0,
}
buf, err := encode(&req)
if err != nil {
return DomainStateNoState, err
}
resp, err := l.request(constants.ProcDomainGetState, constants.ProgramRemote, &buf)
if err != nil {
return DomainStateNoState, err
}
r := <-resp
if r.Status != StatusOK {
return DomainStateNoState, decodeError(r.Payload)
}
result := struct {
State uint32
Reason uint32
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
if err != nil {
return DomainStateNoState, err
}
return DomainState(result.State), nil
}
// Events streams domain events.
// 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) Events(dom string) (<-chan DomainEvent, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
payload := struct {
Padding [4]byte
Domain Domain
Event [2]byte
Flags [2]byte
}{
Padding: [4]byte{0x0, 0x0, 0x1, 0x0},
Domain: *d,
Event: [2]byte{0x0, 0x0},
Flags: [2]byte{0x0, 0x0},
}
buf, err := encode(&payload)
if err != nil {
return nil, err
}
resp, err := l.request(constants.QEMUConnectDomainMonitorEventRegister, constants.ProgramQEMU, &buf)
if err != nil {
return nil, err
}
res := <-resp
if res.Status != StatusOK {
err := decodeError(res.Payload)
if err == ErrUnsupported {
return nil, ErrEventsNotSupported
}
return nil, decodeError(res.Payload)
}
dec := xdr.NewDecoder(bytes.NewReader(res.Payload))
cbID, _, err := dec.DecodeUint()
if err != nil {
return nil, err
}
stream := make(chan *DomainEvent)
l.addStream(cbID, stream)
c := make(chan DomainEvent)
go func() {
// process events
for e := range stream {
c <- *e
}
}()
return c, nil
}
// Migrate synchronously migrates the domain specified by dom, e.g.,
// 'prod-lb-01', to the destination hypervisor specified by dest, e.g.,
// 'qemu+tcp://example.com/system'. The flags argument determines the
// type of migration and how it will be performed. For more information
// on available migration flags and their meaning, see MigrateFlag*.
func (l *Libvirt) Migrate(dom string, dest string, flags MigrateFlags) error {
_, err := url.Parse(dest)
if err != nil {
return err
}
d, err := l.lookup(dom)
if err != nil {
return err
}
// Two unknowns remain here , Libvirt specifies RemoteParameters
// and CookieIn. In testing both values are always set to 0 by virsh
// and the source does not provide clear definitions of their purpose.
// For now, using the same zero'd values as done by virsh will be Good Enough.
payload := struct {
Domain Domain
Padding [4]byte
DestinationURI string
RemoteParameters uint32
CookieIn uint32
Flags MigrateFlags
}{
Domain: *d,
Padding: [4]byte{0x0, 0x0, 0x0, 0x1},
DestinationURI: dest,
RemoteParameters: 0,
CookieIn: 0,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcMigratePerformParams, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// MigrateSetMaxSpeed set the maximum migration bandwidth (in MiB/s) for a
// domain which is being migrated to another host. Specifying a negative value
// results in an essentially unlimited value being provided to the hypervisor.
func (l *Libvirt) MigrateSetMaxSpeed(dom string, speed int64) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
payload := struct {
Padding [4]byte
Domain Domain
Bandwidth int64
Flags uint32
}{
Padding: [4]byte{0x0, 0x0, 0x1, 0x0},
Domain: *d,
Bandwidth: speed,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainMigrateSetMaxSpeed, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return 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
}
resp, err := l.request(constants.QEMUDomainMonitor, constants.ProgramQEMU, &buf)
if err != nil {
return nil, err
}
res := <-resp
// check for libvirt errors
if res.Status != StatusOK {
return nil, decodeError(res.Payload)
}
// 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.
func (l *Libvirt) Secrets() ([]Secret, error) {
req := struct {
NeedResults uint32
Flags uint32
}{
NeedResults: 1,
Flags: 0, // unused per libvirt source, callers should pass 0
}
buf, err := encode(&req)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcConnectListAllSecrets, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
result := struct {
Secrets []Secret
Count uint32
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
if err != nil {
return nil, err
}
return result.Secrets, nil
}
// StoragePool returns the storage pool associated with the provided name.
// An error is returned if the requested storage pool is not found.
func (l *Libvirt) StoragePool(name string) (*StoragePool, error) {
req := struct {
Name string
}{
Name: name,
}
buf, err := encode(&req)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcStoragePoolLookupByName, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
result := struct {
Pool StoragePool
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
if err != nil {
return nil, err
}
return &result.Pool, nil
}
// StoragePoolRefresh refreshes the storage pool specified by name.
func (l *Libvirt) StoragePoolRefresh(name string) error {
pool, err := l.StoragePool(name)
if err != nil {
return err
}
req := struct {
Pool StoragePool
Flags uint32
}{
Pool: *pool,
Flags: 0, // unused per libvirt source, callers should pass 0
}
buf, err := encode(&req)
if err != nil {
return err
}
resp, err := l.request(constants.ProcStoragePoolRefresh, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// StoragePools returns a list of defined storage pools. Pools are filtered by
// the provided flags. See StoragePools*.
func (l *Libvirt) StoragePools(flags StoragePoolsFlags) ([]StoragePool, error) {
req := struct {
NeedResults uint32
Flags StoragePoolsFlags
}{
NeedResults: 1,
Flags: flags,
}
buf, err := encode(&req)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcConnectListAllStoragePools, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
result := struct {
Pools []StoragePool
Count uint32
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
if err != nil {
return nil, err
}
return result.Pools, nil
}
// 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 UndefineFlag*.
func (l *Libvirt) Undefine(dom string, flags UndefineFlags) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
payload := struct {
Domain Domain
Flags UndefineFlags
}{
Domain: *d,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainUndefineFlags, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// 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 DestroyFlag*.
func (l *Libvirt) Destroy(dom string, flags DestroyFlags) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
payload := struct {
Domain Domain
Flags DestroyFlags
}{
Domain: *d,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainDestroyFlags, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// XML returns a domain's raw XML definition, akin to `virsh dumpxml <domain>`.
// See DomainXMLFlag* for optional flags.
func (l *Libvirt) XML(dom string, flags DomainXMLFlags) ([]byte, error) {
d, err := l.lookup(dom)
if err != nil {
return nil, err
}
payload := struct {
Domain Domain
Flags DomainXMLFlags
}{
Domain: *d,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcDomainGetXMLDesc, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
pl := bytes.NewReader(r.Payload)
dec := xdr.NewDecoder(pl)
s, _, err := dec.DecodeString()
if err != nil {
return nil, err
}
return []byte(s), nil
}
// DefineXML defines a domain, but does not start it.
func (l *Libvirt) DefineXML(x []byte, flags DomainDefineXMLFlags) error {
payload := struct {
Domain []byte
Flags DomainDefineXMLFlags
}{
Domain: x,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainDefineXMLFlags, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// Version returns the version of the libvirt daemon.
func (l *Libvirt) Version() (string, error) {
resp, err := l.request(constants.ProcConnectGetLibVersion, constants.ProgramRemote, nil)
if err != nil {
return "", err
}
r := <-resp
if r.Status != StatusOK {
return "", decodeError(r.Payload)
}
result := struct {
Version uint64
}{}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
_, err = dec.Decode(&result)
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 := result.Version / 1000000
result.Version %= 1000000
minor := result.Version / 1000
result.Version %= 1000
micro := result.Version
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.
func (l *Libvirt) Shutdown(dom string, flags ShutdownFlags) error {
d, err := l.lookup(dom)
if err != nil {
return err
}
payload := struct {
Domain Domain
Flags ShutdownFlags
}{
Domain: *d,
Flags: flags,
}
buf, err := encode(&payload)
if err != nil {
return err
}
resp, err := l.request(constants.ProcDomainShutdownFlags, constants.ProgramRemote, &buf)
if err != nil {
return err
}
r := <-resp
if r.Status != StatusOK {
return decodeError(r.Payload)
}
return nil
}
// lookup returns a domain as seen by libvirt.
func (l *Libvirt) lookup(name string) (*Domain, error) {
payload := struct {
Name string
}{name}
buf, err := encode(&payload)
if err != nil {
return nil, err
}
resp, err := l.request(constants.ProcDomainLookupByName, constants.ProgramRemote, &buf)
if err != nil {
return nil, err
}
r := <-resp
if r.Status != StatusOK {
return nil, decodeError(r.Payload)
}
dec := xdr.NewDecoder(bytes.NewReader(r.Payload))
var d Domain
_, err = dec.Decode(&d)
if err != nil {
return nil, err
}
return &d, nil
}
// 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
}
// New configures a new Libvirt RPC connection.
func New(conn net.Conn) *Libvirt {
l := &Libvirt{
conn: conn,
s: 0,
r: bufio.NewReader(conn),
w: bufio.NewWriter(conn),
callbacks: make(map[uint32]chan response),
events: make(map[uint32]chan *DomainEvent),
}
go l.listen()
return l
}