package cmd import ( "context" "fmt" "github.com/spf13/cobra" "log" "os" "os/signal" "syscall" ) // daemonCmd represents the daemon command var daemonCmd = &cobra.Command{ Use: "daemon", Short: "start daemon", Run: doDaemon, } func init() { RootCmd.AddCommand(daemonCmd) } type jobLogger struct { MainLog Logger JobName string } func (l jobLogger) Printf(format string, v ...interface{}) { l.MainLog.Printf(fmt.Sprintf("[%s]: %s", l.JobName, format), v...) } type Job interface { JobName() string JobStart(ctxt context.Context) } func doDaemon(cmd *cobra.Command, args []string) { log := log.New(os.Stderr, "", log.LUTC|log.Ldate|log.Ltime) ctx := context.Background() ctx = context.WithValue(ctx, contextKeyLog, log) conf, err := ParseConfig(ctx, rootArgs.configFile) if err != nil { log.Printf("error parsing config: %s", err) os.Exit(1) } d := NewDaemon(conf) d.Loop(ctx) } type contextKey string const ( contextKeyLog contextKey = contextKey("log") ) type Daemon struct { conf *Config } func NewDaemon(initialConf *Config) *Daemon { return &Daemon{initialConf} } func (d *Daemon) Loop(ctx context.Context) { log := ctx.Value(contextKeyLog).(Logger) ctx, cancel := context.WithCancel(ctx) sigChan := make(chan os.Signal, 1) finishs := make(chan Job) signal.Notify(sigChan, syscall.SIGINT, syscall.SIGTERM) log.Printf("starting jobs from config") i := 0 for _, job := range d.conf.Jobs { log.Printf("starting job %s", job.JobName()) logger := jobLogger{log, job.JobName()} i++ jobCtx := context.WithValue(ctx, contextKeyLog, logger) go func(j Job) { j.JobStart(jobCtx) finishs <- j }(job) } finishCount := 0 outer: for { select { case j := <-finishs: log.Printf("job finished: %s", j.JobName()) finishCount++ if finishCount == len(d.conf.Jobs) { log.Printf("all jobs finished") break outer } case sig := <-sigChan: log.Printf("received signal: %s", sig) log.Printf("cancelling all jobs") cancel() } } signal.Stop(sigChan) log.Printf("exiting") }