harbor/job/statemachine.go
2016-05-30 14:44:03 +08:00

270 lines
8.9 KiB
Go

package job
import (
"fmt"
"sync"
"github.com/vmware/harbor/dao"
"github.com/vmware/harbor/job/config"
"github.com/vmware/harbor/job/replication"
"github.com/vmware/harbor/job/utils"
"github.com/vmware/harbor/models"
uti "github.com/vmware/harbor/utils"
"github.com/vmware/harbor/utils/log"
)
// RepJobParm wraps the parm of a job
type RepJobParm struct {
LocalRegURL string
TargetURL string
TargetUsername string
TargetPassword string
Repository string
Tags []string
Enabled int
Operation string
}
// SM is the state machine to handle job, it handles one job at a time.
type SM struct {
JobID int64
CurrentState string
PreviousState string
//The states that don't have to exist in transition map, such as "Error", "Canceled"
ForcedStates map[string]struct{}
Transitions map[string]map[string]struct{}
Handlers map[string]StateHandler
desiredState string
Logger *log.Logger
Parms *RepJobParm
lock *sync.Mutex
}
// EnterState transit the statemachine from the current state to the state in parameter.
// It returns the next state the statemachine should tranit to.
func (sm *SM) EnterState(s string) (string, error) {
log.Debugf("Job id: %d, transiting from State: %s, to State: %s", sm.JobID, sm.CurrentState, s)
targets, ok := sm.Transitions[sm.CurrentState]
_, exist := targets[s]
_, isForced := sm.ForcedStates[s]
if !exist && !isForced {
return "", fmt.Errorf("Job id: %d, transition from %s to %s does not exist!", sm.JobID, sm.CurrentState, s)
}
exitHandler, ok := sm.Handlers[sm.CurrentState]
if ok {
if err := exitHandler.Exit(); err != nil {
return "", err
}
} else {
log.Debugf("Job id: %d, no handler found for state:%s, skip", sm.JobID, sm.CurrentState)
}
enterHandler, ok := sm.Handlers[s]
var next = models.JobContinue
var err error
if ok {
if next, err = enterHandler.Enter(); err != nil {
return "", err
}
} else {
log.Debugf("Job id: %d, no handler found for state:%s, skip", sm.JobID, s)
}
sm.PreviousState = sm.CurrentState
sm.CurrentState = s
log.Debugf("Job id: %d, transition succeeded, current state: %s", sm.JobID, s)
return next, nil
}
// Start kicks off the statemachine to transit from current state to s, and moves on
// It will search the transit map if the next state is "_continue", and
// will enter error state if there's more than one possible path when next state is "_continue"
func (sm *SM) Start(s string) {
n, err := sm.EnterState(s)
log.Debugf("Job id: %d, next state from handler: %s", sm.JobID, n)
for len(n) > 0 && err == nil {
if d := sm.getDesiredState(); len(d) > 0 {
log.Debugf("Job id: %d. Desired state: %s, will ignore the next state from handler", sm.JobID, d)
n = d
sm.setDesiredState("")
continue
}
if n == models.JobContinue && len(sm.Transitions[sm.CurrentState]) == 1 {
for n = range sm.Transitions[sm.CurrentState] {
break
}
log.Debugf("Job id: %d, Continue to state: %s", sm.JobID, n)
continue
}
if n == models.JobContinue && len(sm.Transitions[sm.CurrentState]) != 1 {
log.Errorf("Job id: %d, next state is continue but there are %d possible next states in transition table", sm.JobID, len(sm.Transitions[sm.CurrentState]))
err = fmt.Errorf("Unable to continue")
break
}
n, err = sm.EnterState(n)
log.Debugf("Job id: %d, next state from handler: %s", sm.JobID, n)
}
if err != nil {
log.Warningf("Job id: %d, the statemachin will enter error state due to error: %v", sm.JobID, err)
sm.EnterState(models.JobError)
}
}
// AddTransition add a transition to the transition table of state machine, the handler is the handler of target state "to"
func (sm *SM) AddTransition(from string, to string, h StateHandler) {
_, ok := sm.Transitions[from]
if !ok {
sm.Transitions[from] = make(map[string]struct{})
}
sm.Transitions[from][to] = struct{}{}
sm.Handlers[to] = h
}
// RemoveTransition removes a transition from transition table of the state machine
func (sm *SM) RemoveTransition(from string, to string) {
_, ok := sm.Transitions[from]
if !ok {
return
}
delete(sm.Transitions[from], to)
}
// Stop will set the desired state as "stopped" such that when next tranisition happen the state machine will stop handling the current job
// and the worker can release itself to the workerpool.
func (sm *SM) Stop(id int64) {
log.Debugf("Trying to stop the job: %d", id)
sm.lock.Lock()
defer sm.lock.Unlock()
//need to check if the sm switched to other job
if id == sm.JobID {
sm.desiredState = models.JobStopped
log.Debugf("Desired state of job %d is set to stopped", id)
} else {
log.Debugf("State machine has switched to job %d, so the action to stop job %d will be ignored", sm.JobID, id)
}
}
func (sm *SM) getDesiredState() string {
sm.lock.Lock()
defer sm.lock.Unlock()
return sm.desiredState
}
func (sm *SM) setDesiredState(s string) {
sm.lock.Lock()
defer sm.lock.Unlock()
sm.desiredState = s
}
// Init initialzie the state machine, it will be called once in the lifecycle of state machine.
func (sm *SM) Init() {
sm.lock = &sync.Mutex{}
sm.Handlers = make(map[string]StateHandler)
sm.Transitions = make(map[string]map[string]struct{})
sm.ForcedStates = map[string]struct{}{
models.JobError: struct{}{},
models.JobStopped: struct{}{},
models.JobCanceled: struct{}{},
}
}
// Reset resets the state machine so it will start handling another job.
func (sm *SM) Reset(jid int64) error {
//To ensure the new jobID is visible to the thread to stop the SM
sm.lock.Lock()
sm.JobID = jid
sm.desiredState = ""
sm.lock.Unlock()
//init parms
job, err := dao.GetRepJob(sm.JobID)
if err != nil {
return fmt.Errorf("Failed to get job, error: %v", err)
}
if job == nil {
return fmt.Errorf("The job doesn't exist in DB, job id: %d", sm.JobID)
}
policy, err := dao.GetRepPolicy(job.PolicyID)
if err != nil {
return fmt.Errorf("Failed to get policy, error: %v", err)
}
if policy == nil {
return fmt.Errorf("The policy doesn't exist in DB, policy id:%d", job.PolicyID)
}
sm.Parms = &RepJobParm{
LocalRegURL: config.LocalHarborURL(),
Repository: job.Repository,
Tags: job.TagList,
Enabled: policy.Enabled,
Operation: job.Operation,
}
if policy.Enabled == 0 {
//worker will cancel this job
return nil
}
target, err := dao.GetRepTarget(policy.TargetID)
if err != nil {
return fmt.Errorf("Failed to get target, error: %v", err)
}
if target == nil {
return fmt.Errorf("The target doesn't exist in DB, target id: %d", policy.TargetID)
}
sm.Parms.TargetURL = target.URL
sm.Parms.TargetUsername = target.Username
pwd := target.Password
if len(pwd) != 0 {
pwd, err = uti.ReversibleDecrypt(pwd)
if err != nil {
return fmt.Errorf("failed to decrypt password: %v", err)
}
}
sm.Parms.TargetPassword = pwd
//init states handlers
sm.Logger = utils.NewLogger(sm.JobID)
sm.Handlers = make(map[string]StateHandler)
sm.Transitions = make(map[string]map[string]struct{})
sm.CurrentState = models.JobPending
sm.AddTransition(models.JobPending, models.JobRunning, StatusUpdater{DummyHandler{JobID: sm.JobID}, models.JobRunning})
sm.Handlers[models.JobError] = StatusUpdater{DummyHandler{JobID: sm.JobID}, models.JobError}
sm.Handlers[models.JobStopped] = StatusUpdater{DummyHandler{JobID: sm.JobID}, models.JobStopped}
switch sm.Parms.Operation {
case models.RepOpTransfer:
err = addImgTransferTransition(sm)
case models.RepOpDelete:
err = addImgDeleteTransition(sm)
default:
err = fmt.Errorf("unsupported operation: %s", sm.Parms.Operation)
}
return err
}
func addImgTransferTransition(sm *SM) error {
base, err := replication.InitBaseHandler(sm.Parms.Repository, sm.Parms.LocalRegURL, config.UISecret(),
sm.Parms.TargetURL, sm.Parms.TargetUsername, sm.Parms.TargetPassword,
sm.Parms.Tags, sm.Logger)
if err != nil {
return err
}
sm.AddTransition(models.JobRunning, replication.StateCheck, &replication.Checker{BaseHandler: base})
sm.AddTransition(replication.StateCheck, replication.StatePullManifest, &replication.ManifestPuller{BaseHandler: base})
sm.AddTransition(replication.StatePullManifest, replication.StateTransferBlob, &replication.BlobTransfer{BaseHandler: base})
sm.AddTransition(replication.StatePullManifest, models.JobFinished, &StatusUpdater{DummyHandler{JobID: sm.JobID}, models.JobFinished})
sm.AddTransition(replication.StateTransferBlob, replication.StatePushManifest, &replication.ManifestPusher{BaseHandler: base})
sm.AddTransition(replication.StatePushManifest, replication.StatePullManifest, &replication.ManifestPuller{BaseHandler: base})
return nil
}
func addImgDeleteTransition(sm *SM) error {
deleter := replication.NewDeleter(sm.Parms.Repository, sm.Parms.Tags, sm.Parms.TargetURL,
sm.Parms.TargetUsername, sm.Parms.TargetPassword, sm.Logger)
sm.AddTransition(models.JobRunning, replication.StateDelete, deleter)
sm.AddTransition(replication.StateDelete, models.JobFinished, &StatusUpdater{DummyHandler{JobID: sm.JobID}, models.JobFinished})
return nil
}