can execute checks concurrently

1 files changed, 41 insertions, 9 deletions

diff --git a/main.go b/main.go
index 5227a1b..6d661d7 100644
--- a/main.go
+++ b/main.go
@@ -4,6 +4,8 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"log"
+	"sync"
 	"time"
 )
 
@@ -21,20 +23,50 @@ func main() {
 		notifyError(config, err)
 	}
 
-	for name, check := range config.Checks {
-		ctx, cancel := context.WithTimeout(context.Background(),
-			time.Duration(config.CheckTimeoutS)*time.Second)
-		defer cancel()
+	type entry struct {
+		name  string
+		check check
+	}
 
-		output, status := check.execute(ctx)
-		stateChanged := state.update(name, status)
+	limiterCh := make(chan struct{}, config.CheckConcurrency)
+	checkCh := make(chan entry)
 
-		if status != ok || stateChanged {
-			subject := fmt.Sprintf("GOGIOS %s: %s", codeToString(status), name)
-			notify(config, subject, output)
+	go func() {
+		for name, check := range config.Checks {
+			checkCh <- entry{name, check}
 		}
+		close(checkCh)
+	}()
+
+	var wg sync.WaitGroup
+	wg.Add(len(config.Checks))
+
+	for entry := range checkCh {
+		go func(name string, check check) {
+			limiterCh <- struct{}{}
+			defer func() {
+				<-limiterCh
+				wg.Done()
+			}()
+
+			ctx, cancel := context.WithTimeout(context.Background(),
+				time.Duration(config.CheckTimeoutS)*time.Second)
+			defer cancel()
+
+			output, status := check.execute(ctx)
+			stateChanged := state.update(name, status)
+
+			if status != ok || stateChanged {
+				subject := fmt.Sprintf("GOGIOS %s: %s", codeToString(status), name)
+				notify(config, subject, output)
+			}
+
+		}(entry.name, entry.check)
 	}
 
+	wg.Wait()
+	log.Println("All checks completed!")
+
 	if err := state.persist(); err != nil {
 		notifyError(config, err)
 	}