feature(worker): ability to hot reload mirror job configrations, close #18

worker/base_provider.go

@@ -0,0 +1,158 @@
+package worker
+
+import (
+	"os"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// baseProvider is the base mixin of providers
+
+type baseProvider struct {
+	sync.Mutex
+
+	ctx      *Context
+	name     string
+	interval time.Duration
+	isMaster bool
+
+	cmd       *cmdJob
+	isRunning atomic.Value
+
+	logFile *os.File
+
+	cgroup *cgroupHook
+	hooks  []jobHook
+}
+
+func (p *baseProvider) Name() string {
+	return p.name
+}
+
+func (p *baseProvider) EnterContext() *Context {
+	p.ctx = p.ctx.Enter()
+	return p.ctx
+}
+
+func (p *baseProvider) ExitContext() *Context {
+	p.ctx, _ = p.ctx.Exit()
+	return p.ctx
+}
+
+func (p *baseProvider) Context() *Context {
+	return p.ctx
+}
+
+func (p *baseProvider) Interval() time.Duration {
+	// logger.Debug("interval for %s: %v", p.Name(), p.interval)
+	return p.interval
+}
+
+func (p *baseProvider) IsMaster() bool {
+	return p.isMaster
+}
+
+func (p *baseProvider) WorkingDir() string {
+	if v, ok := p.ctx.Get(_WorkingDirKey); ok {
+		if s, ok := v.(string); ok {
+			return s
+		}
+	}
+	panic("working dir is impossible to be non-exist")
+}
+
+func (p *baseProvider) LogDir() string {
+	if v, ok := p.ctx.Get(_LogDirKey); ok {
+		if s, ok := v.(string); ok {
+			return s
+		}
+	}
+	panic("log dir is impossible to be unavailable")
+}
+
+func (p *baseProvider) LogFile() string {
+	if v, ok := p.ctx.Get(_LogFileKey); ok {
+		if s, ok := v.(string); ok {
+			return s
+		}
+	}
+	panic("log dir is impossible to be unavailable")
+}
+
+func (p *baseProvider) AddHook(hook jobHook) {
+	if cg, ok := hook.(*cgroupHook); ok {
+		p.cgroup = cg
+	}
+	p.hooks = append(p.hooks, hook)
+}
+
+func (p *baseProvider) Hooks() []jobHook {
+	return p.hooks
+}
+
+func (p *baseProvider) Cgroup() *cgroupHook {
+	return p.cgroup
+}
+
+func (p *baseProvider) prepareLogFile() error {
+	if p.LogFile() == "/dev/null" {
+		p.cmd.SetLogFile(nil)
+		return nil
+	}
+	if p.logFile == nil {
+		logFile, err := os.OpenFile(p.LogFile(), os.O_WRONLY|os.O_CREATE, 0644)
+		if err != nil {
+			logger.Errorf("Error opening logfile %s: %s", p.LogFile(), err.Error())
+			return err
+		}
+		p.logFile = logFile
+	}
+	p.cmd.SetLogFile(p.logFile)
+	return nil
+}
+
+func (p *baseProvider) Run() error {
+	panic("Not Implemented")
+}
+
+func (p *baseProvider) Start() error {
+	panic("Not Implemented")
+}
+
+func (p *baseProvider) IsRunning() bool {
+	isRunning, _ := p.isRunning.Load().(bool)
+	return isRunning
+}
+
+func (p *baseProvider) Wait() error {
+	defer func() {
+		p.Lock()
+		p.isRunning.Store(false)
+		if p.logFile != nil {
+			p.logFile.Close()
+			p.logFile = nil
+		}
+		p.Unlock()
+	}()
+	return p.cmd.Wait()
+}
+
+func (p *baseProvider) Terminate() error {
+	logger.Debugf("terminating provider: %s", p.Name())
+	if !p.IsRunning() {
+		return nil
+	}
+
+	p.Lock()
+	if p.logFile != nil {
+		p.logFile.Close()
+		p.logFile = nil
+	}
+	p.Unlock()
+
+	err := p.cmd.Terminate()
+	p.isRunning.Store(false)
+
+	return err
+}