forked from canonical/lxd
/
operations.go
675 lines (548 loc) · 15.1 KB
/
operations.go
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package main
import (
"fmt"
"net/http"
"runtime"
"strings"
"sync"
"time"
"github.com/gorilla/mux"
"github.com/gorilla/websocket"
"github.com/pborman/uuid"
"github.com/pkg/errors"
"github.com/lxc/lxd/lxd/cluster"
"github.com/lxc/lxd/lxd/db"
"github.com/lxc/lxd/lxd/util"
"github.com/lxc/lxd/shared"
"github.com/lxc/lxd/shared/api"
"github.com/lxc/lxd/shared/cancel"
"github.com/lxc/lxd/shared/logger"
"github.com/lxc/lxd/shared/version"
)
var operationsLock sync.Mutex
var operations map[string]*operation = make(map[string]*operation)
type operationClass int
const (
operationClassTask operationClass = 1
operationClassWebsocket operationClass = 2
operationClassToken operationClass = 3
)
func (t operationClass) String() string {
return map[operationClass]string{
operationClassTask: "task",
operationClassWebsocket: "websocket",
operationClassToken: "token",
}[t]
}
type operation struct {
id string
class operationClass
createdAt time.Time
updatedAt time.Time
status api.StatusCode
url string
resources map[string][]string
metadata map[string]interface{}
err string
readonly bool
canceler *cancel.Canceler
description string
// Those functions are called at various points in the operation lifecycle
onRun func(*operation) error
onCancel func(*operation) error
onConnect func(*operation, *http.Request, http.ResponseWriter) error
// Channels used for error reporting and state tracking of background actions
chanDone chan error
// Locking for concurent access to the operation
lock sync.Mutex
cluster *db.Cluster
}
func (op *operation) done() {
if op.readonly {
return
}
op.lock.Lock()
op.readonly = true
op.onRun = nil
op.onCancel = nil
op.onConnect = nil
close(op.chanDone)
op.lock.Unlock()
time.AfterFunc(time.Second*5, func() {
operationsLock.Lock()
_, ok := operations[op.id]
if !ok {
operationsLock.Unlock()
return
}
delete(operations, op.id)
operationsLock.Unlock()
err := op.cluster.Transaction(func(tx *db.ClusterTx) error {
return tx.OperationRemove(op.id)
})
if err != nil {
logger.Warnf("Failed to delete operation %s: %s", op.id, err)
}
/*
* When we create a new lxc.Container, it adds a finalizer (via
* SetFinalizer) that frees the struct. However, it sometimes
* takes the go GC a while to actually free the struct,
* presumably since it is a small amount of memory.
* Unfortunately, the struct also keeps the log fd open, so if
* we leave too many of these around, we end up running out of
* fds. So, let's explicitly do a GC to collect these at the
* end of each request.
*/
runtime.GC()
})
}
func (op *operation) Run() (chan error, error) {
if op.status != api.Pending {
return nil, fmt.Errorf("Only pending operations can be started")
}
chanRun := make(chan error, 1)
op.lock.Lock()
op.status = api.Running
if op.onRun != nil {
go func(op *operation, chanRun chan error) {
err := op.onRun(op)
if err != nil {
op.lock.Lock()
op.status = api.Failure
op.err = SmartError(err).String()
op.lock.Unlock()
op.done()
chanRun <- err
logger.Debugf("Failure for %s operation: %s: %s", op.class.String(), op.id, err)
_, md, _ := op.Render()
eventSend("operation", md)
return
}
op.lock.Lock()
op.status = api.Success
op.lock.Unlock()
op.done()
chanRun <- nil
op.lock.Lock()
logger.Debugf("Success for %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
op.lock.Unlock()
}(op, chanRun)
}
op.lock.Unlock()
logger.Debugf("Started %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
return chanRun, nil
}
func (op *operation) Cancel() (chan error, error) {
if op.status != api.Running {
return nil, fmt.Errorf("Only running operations can be cancelled")
}
if !op.mayCancel() {
return nil, fmt.Errorf("This operation can't be cancelled")
}
chanCancel := make(chan error, 1)
op.lock.Lock()
oldStatus := op.status
op.status = api.Cancelling
op.lock.Unlock()
if op.onCancel != nil {
go func(op *operation, oldStatus api.StatusCode, chanCancel chan error) {
err := op.onCancel(op)
if err != nil {
op.lock.Lock()
op.status = oldStatus
op.lock.Unlock()
chanCancel <- err
logger.Debugf("Failed to cancel %s operation: %s: %s", op.class.String(), op.id, err)
_, md, _ := op.Render()
eventSend("operation", md)
return
}
op.lock.Lock()
op.status = api.Cancelled
op.lock.Unlock()
op.done()
chanCancel <- nil
logger.Debugf("Cancelled %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
}(op, oldStatus, chanCancel)
}
logger.Debugf("Cancelling %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
if op.canceler != nil {
err := op.canceler.Cancel()
if err != nil {
return nil, err
}
}
if op.onCancel == nil {
op.lock.Lock()
op.status = api.Cancelled
op.lock.Unlock()
op.done()
chanCancel <- nil
}
logger.Debugf("Cancelled %s operation: %s", op.class.String(), op.id)
_, md, _ = op.Render()
eventSend("operation", md)
return chanCancel, nil
}
func (op *operation) Connect(r *http.Request, w http.ResponseWriter) (chan error, error) {
if op.class != operationClassWebsocket {
return nil, fmt.Errorf("Only websocket operations can be connected")
}
if op.status != api.Running {
return nil, fmt.Errorf("Only running operations can be connected")
}
chanConnect := make(chan error, 1)
op.lock.Lock()
go func(op *operation, chanConnect chan error) {
err := op.onConnect(op, r, w)
if err != nil {
chanConnect <- err
logger.Debugf("Failed to handle %s operation: %s: %s", op.class.String(), op.id, err)
return
}
chanConnect <- nil
logger.Debugf("Handled %s operation: %s", op.class.String(), op.id)
}(op, chanConnect)
op.lock.Unlock()
logger.Debugf("Connected %s operation: %s", op.class.String(), op.id)
return chanConnect, nil
}
func (op *operation) mayCancel() bool {
if op.class == operationClassToken {
return true
}
if op.onCancel != nil {
return true
}
if op.canceler != nil && op.canceler.Cancelable() {
return true
}
return false
}
func (op *operation) Render() (string, *api.Operation, error) {
// Setup the resource URLs
resources := op.resources
if resources != nil {
tmpResources := make(map[string][]string)
for key, value := range resources {
var values []string
for _, c := range value {
values = append(values, fmt.Sprintf("/%s/%s/%s", version.APIVersion, key, c))
}
tmpResources[key] = values
}
resources = tmpResources
}
return op.url, &api.Operation{
ID: op.id,
Class: op.class.String(),
Description: op.description,
CreatedAt: op.createdAt,
UpdatedAt: op.updatedAt,
Status: op.status.String(),
StatusCode: op.status,
Resources: resources,
Metadata: op.metadata,
MayCancel: op.mayCancel(),
Err: op.err,
}, nil
}
func (op *operation) WaitFinal(timeout int) (bool, error) {
// Check current state
if op.status.IsFinal() {
return true, nil
}
// Wait indefinitely
if timeout == -1 {
<-op.chanDone
return true, nil
}
// Wait until timeout
if timeout > 0 {
timer := time.NewTimer(time.Duration(timeout) * time.Second)
select {
case <-op.chanDone:
return false, nil
case <-timer.C:
return false, nil
}
}
return false, nil
}
func (op *operation) UpdateResources(opResources map[string][]string) error {
if op.status != api.Pending && op.status != api.Running {
return fmt.Errorf("Only pending or running operations can be updated")
}
if op.readonly {
return fmt.Errorf("Read-only operations can't be updated")
}
op.lock.Lock()
op.updatedAt = time.Now()
op.resources = opResources
op.lock.Unlock()
logger.Debugf("Updated resources for %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
return nil
}
func (op *operation) UpdateMetadata(opMetadata interface{}) error {
if op.status != api.Pending && op.status != api.Running {
return fmt.Errorf("Only pending or running operations can be updated")
}
if op.readonly {
return fmt.Errorf("Read-only operations can't be updated")
}
newMetadata, err := shared.ParseMetadata(opMetadata)
if err != nil {
return err
}
op.lock.Lock()
op.updatedAt = time.Now()
op.metadata = newMetadata
op.lock.Unlock()
logger.Debugf("Updated metadata for %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
return nil
}
func operationCreate(cluster *db.Cluster, opClass operationClass, description string, opResources map[string][]string, opMetadata interface{}, onRun func(*operation) error, onCancel func(*operation) error, onConnect func(*operation, *http.Request, http.ResponseWriter) error) (*operation, error) {
// Main attributes
op := operation{}
op.id = uuid.NewRandom().String()
op.description = description
op.class = opClass
op.createdAt = time.Now()
op.updatedAt = op.createdAt
op.status = api.Pending
op.url = fmt.Sprintf("/%s/operations/%s", version.APIVersion, op.id)
op.resources = opResources
op.chanDone = make(chan error)
op.cluster = cluster
newMetadata, err := shared.ParseMetadata(opMetadata)
if err != nil {
return nil, err
}
op.metadata = newMetadata
// Callback functions
op.onRun = onRun
op.onCancel = onCancel
op.onConnect = onConnect
// Sanity check
if op.class != operationClassWebsocket && op.onConnect != nil {
return nil, fmt.Errorf("Only websocket operations can have a Connect hook")
}
if op.class == operationClassWebsocket && op.onConnect == nil {
return nil, fmt.Errorf("Websocket operations must have a Connect hook")
}
if op.class == operationClassToken && op.onRun != nil {
return nil, fmt.Errorf("Token operations can't have a Run hook")
}
if op.class == operationClassToken && op.onCancel != nil {
return nil, fmt.Errorf("Token operations can't have a Cancel hook")
}
operationsLock.Lock()
operations[op.id] = &op
operationsLock.Unlock()
err = op.cluster.Transaction(func(tx *db.ClusterTx) error {
_, err := tx.OperationAdd(op.id)
return err
})
if err != nil {
return nil, errors.Wrapf(err, "failed to add operation %s to database", op.id)
}
logger.Debugf("New %s operation: %s", op.class.String(), op.id)
_, md, _ := op.Render()
eventSend("operation", md)
return &op, nil
}
func operationGet(id string) (*operation, error) {
operationsLock.Lock()
op, ok := operations[id]
operationsLock.Unlock()
if !ok {
return nil, fmt.Errorf("Operation '%s' doesn't exist", id)
}
return op, nil
}
// API functions
func operationAPIGet(d *Daemon, r *http.Request) Response {
id := mux.Vars(r)["id"]
var body *api.Operation
// First check the local cache, then the cluster database table.
op, err := operationGet(id)
if err == nil {
_, body, err = op.Render()
if err != nil {
return SmartError(err)
}
} else {
var address string
err = d.cluster.Transaction(func(tx *db.ClusterTx) error {
operation, err := tx.OperationByUUID(id)
if err != nil {
return err
}
address = operation.NodeAddress
return nil
})
if err != nil {
return SmartError(err)
}
cert := d.endpoints.NetworkCert()
client, err := cluster.Connect(address, cert, false)
if err != nil {
return SmartError(err)
}
body, _, err = client.GetOperation(id)
if err != nil {
return SmartError(err)
}
}
return SyncResponse(true, body)
}
func operationAPIDelete(d *Daemon, r *http.Request) Response {
id := mux.Vars(r)["id"]
op, err := operationGet(id)
if err != nil {
return NotFound
}
_, err = op.Cancel()
if err != nil {
return BadRequest(err)
}
return EmptySyncResponse
}
var operationCmd = Command{name: "operations/{id}", get: operationAPIGet, delete: operationAPIDelete}
func operationsAPIGet(d *Daemon, r *http.Request) Response {
var md shared.Jmap
recursion := util.IsRecursionRequest(r)
md = shared.Jmap{}
operationsLock.Lock()
ops := operations
operationsLock.Unlock()
for _, v := range ops {
status := strings.ToLower(v.status.String())
_, ok := md[status]
if !ok {
if recursion {
md[status] = make([]*api.Operation, 0)
} else {
md[status] = make([]string, 0)
}
}
if !recursion {
md[status] = append(md[status].([]string), v.url)
continue
}
_, body, err := v.Render()
if err != nil {
continue
}
md[status] = append(md[status].([]*api.Operation), body)
}
return SyncResponse(true, md)
}
var operationsCmd = Command{name: "operations", get: operationsAPIGet}
func operationAPIWaitGet(d *Daemon, r *http.Request) Response {
timeout, err := shared.AtoiEmptyDefault(r.FormValue("timeout"), -1)
if err != nil {
return InternalError(err)
}
id := mux.Vars(r)["id"]
op, err := operationGet(id)
if err != nil {
return NotFound
}
_, err = op.WaitFinal(timeout)
if err != nil {
return InternalError(err)
}
_, body, err := op.Render()
if err != nil {
return SmartError(err)
}
return SyncResponse(true, body)
}
var operationWait = Command{name: "operations/{id}/wait", get: operationAPIWaitGet}
type operationWebSocket struct {
req *http.Request
op *operation
}
func (r *operationWebSocket) Render(w http.ResponseWriter) error {
chanErr, err := r.op.Connect(r.req, w)
if err != nil {
return err
}
err = <-chanErr
return err
}
func (r *operationWebSocket) String() string {
_, md, err := r.op.Render()
if err != nil {
return fmt.Sprintf("error: %s", err)
}
return md.ID
}
type forwardedOperationWebSocket struct {
req *http.Request
id string
source *websocket.Conn // Connection to the node were the operation is running
}
func (r *forwardedOperationWebSocket) Render(w http.ResponseWriter) error {
target, err := shared.WebsocketUpgrader.Upgrade(w, r.req, nil)
if err != nil {
return err
}
<-shared.WebsocketProxy(r.source, target)
return nil
}
func (r *forwardedOperationWebSocket) String() string {
return r.id
}
func operationAPIWebsocketGet(d *Daemon, r *http.Request) Response {
id := mux.Vars(r)["id"]
// First check if the websocket is for a local operation from this
// node.
op, err := operationGet(id)
if err == nil {
return &operationWebSocket{r, op}
}
// Secondly check if the websocket is from an operation on another
// node, and, if so, proxy it.
secret := r.FormValue("secret")
if secret == "" {
return BadRequest(fmt.Errorf("missing secret"))
}
var address string
err = d.cluster.Transaction(func(tx *db.ClusterTx) error {
operation, err := tx.OperationByUUID(id)
if err != nil {
return err
}
address = operation.NodeAddress
return nil
})
if err != nil {
return SmartError(err)
}
cert := d.endpoints.NetworkCert()
client, err := cluster.Connect(address, cert, false)
if err != nil {
return SmartError(err)
}
logger.Debugf("Forward operation websocket from node %s", address)
source, err := client.GetOperationWebsocket(id, secret)
if err != nil {
return SmartError(err)
}
return &forwardedOperationWebSocket{req: r, id: id, source: source}
}
var operationWebsocket = Command{name: "operations/{id}/websocket", untrustedGet: true, get: operationAPIWebsocketGet}