started on framework for running recurring checks

check/check_ping.go

@@ -65,7 +65,7 @@ func (c *CheckPing) Check(debuglvl int) error {
 		}
 	}
 
-	if debuglvl > 0 {
+	if debuglvl > 1 {
 		fmt.Printf("Packet loss: %.f%%\n", stats.PacketLoss)
 		fmt.Printf("Max RTT: %s\n", stats.MaxRtt.String())
 		fmt.Printf("Max Configured RTT: %s\n", c.MaxRTT.String())

config/config.go

@@ -3,6 +3,8 @@ package config
 import (
 	"alrm/alarm"
 	"fmt"
+	"runtime"
+	"strconv"
 	"time"
 )
 
@@ -10,12 +12,15 @@ type Config struct {
 	Groups   map[string]*Group
 	Alarms   map[string]alarm.Alarm
 	Interval time.Duration
+	Threads  int
 }
 
 func NewConfig() *Config {
 	return &Config{
 		// Default check interval, 30 seconds
 		Interval: time.Second * 30,
+		// Default number of threads, use local CPU count
+		Threads: runtime.NumCPU(),
 	}
 }
 
@@ -61,6 +66,16 @@ func (c *Config) SetInterval(val string) error {
 	return nil
 }
 
+func (c *Config) SetThreads(val string) error {
+	threads, err := strconv.Atoi(val)
+	if err != nil {
+		return err
+	}
+
+	c.Threads = threads
+	return nil
+}
+
 func ReadConfig(fn string, debuglvl int) (*Config, error) {
 	parser := &Parser{DebugLevel: debuglvl}
 	config, err := parser.Parse(fn)

config/parser.go

@@ -63,6 +63,14 @@ func (p *Parser) Parse(fn string) (*Config, error) {
 			switch key {
 			case "interval":
 				err := config.SetInterval(value)
+				if err != nil {
+					return nil, fmt.Errorf(
+						"invalid duration for interval in %s, line %d: \"%s\"",
+						fn, tok.Line(), value,
+					)
+				}
+			case "threads":
+				err := config.SetThreads(value)
 				if err != nil {
 					return nil, fmt.Errorf(
 						"invalid number for interval in %s, line %d: \"%s\"",

main.go

@@ -109,6 +109,19 @@ func main() {
 		}
 		fmt.Printf("check successful\n")
 
+	case "server":
+		cfg, err := config.ReadConfig(*cfgPath, *debuglvl)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s\n", err.Error())
+			os.Exit(1)
+		}
+
+		err = startServer(cfg, *debuglvl)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "%s\n", err.Error())
+			os.Exit(1)
+		}
+
 	case "help", "":
 		printUsage()
 
@@ -127,4 +140,5 @@ func printUsage() {
 	fmt.Printf("  verify configuration:     %s [args] config\n", os.Args[0])
 	fmt.Printf("  run a check manually:     %s [args] check <host/group>\n", os.Args[0])
 	fmt.Printf("  test an alarm:            %s [args] alarm <name>\n", os.Args[0])
+	fmt.Printf("  start server (forground): %s [args] server\n", os.Args[0])
 }

server.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"alrm/check"
+	"alrm/config"
+	"fmt"
+	"time"
+)
+
+func startServer(cfg *config.Config, debuglvl int) error {
+	ch := make(chan check.Check, cfg.Threads)
+	for i := 0; i < cfg.Threads; i++ {
+		go worker(ch, debuglvl)
+	}
+
+	t := time.NewTicker(cfg.Interval)
+	defer t.Stop()
+	for {
+		select {
+		case r := <-t.C:
+			if debuglvl > 0 {
+				fmt.Printf("Interval check at %s\n", r)
+			}
+			for _, g := range cfg.Groups {
+				for _, h := range g.Hosts {
+					for _, c := range h.Checks {
+						ch <- c
+					}
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func worker(ch chan check.Check, debuglvl int) {
+	for {
+		chk := <-ch
+		err := chk.Check(debuglvl)
+		if err != nil {
+			fmt.Printf("Check error: %s\n", err)
+		}
+	}
+}