heartbeat support

cmd/everssl/main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/mysteriumnetwork/everssl/reporter"
 	"github.com/mysteriumnetwork/everssl/validator"
 	"github.com/mysteriumnetwork/everssl/validator/result"
+	"github.com/mysteriumnetwork/everssl/heartbeat"
 )
 
 var version = "undefined"
@@ -38,6 +39,8 @@ var (
 	ignoreExpirationErrors   = flag.Bool("ignore-expiration-errors", false, "ignore expiration errors")
 
 	pagerDutyKey = flag.String("pagerduty-key", "", "PagerDuty Events V2 integration key")
+
+	heartbeatURL = flag.String("heartbeat-url", "", "heartbeat URL, URL to GET after successful finish")
 )
 
 func run() int {
@@ -66,6 +69,13 @@ func run() int {
 		}
 	}
 
+	if *heartbeatURL == "" {
+		envToken := os.Getenv("HEARTBEAT_URL")
+		if envToken != "" {
+			*heartbeatURL = envToken
+		}
+	}
+
 	if *zoneName == "" {
 		log.Fatal("zone is not specified")
 	}
@@ -144,6 +154,14 @@ func run() int {
 		log.Fatal(err)
 	}
 
+	if *heartbeatURL != "" {
+		var beat heartbeat.Heartbeat = heartbeat.NewURLHeartbeat(*heartbeatURL)
+		err = beat.Beat(ctx)
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
 	return 0
 }
 

heartbeat/heartbeat.go

@@ -0,0 +1,9 @@
+package heartbeat
+
+import (
+	"context"
+)
+
+type Heartbeat interface {
+	Beat(context.Context) error
+}

heartbeat/url.go

@@ -0,0 +1,46 @@
+package heartbeat
+
+import (
+	"context"
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+const discardLimit int64 = 128 * 1024
+
+type URLHeartbeat struct {
+	url string
+}
+
+func NewURLHeartbeat(url string) *URLHeartbeat {
+	return &URLHeartbeat{
+		url: url,
+	}
+}
+
+func (b *URLHeartbeat) Beat(ctx context.Context) error {
+	req, err := http.NewRequestWithContext(ctx, "GET", b.url, nil)
+	if err != nil {
+		return err
+	}
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		return err
+	}
+	defer cleanupBody(resp.Body)
+
+	return nil
+}
+
+// Does cleanup of HTTP response in order to make it reusable by keep-alive
+// logic of HTTP client
+func cleanupBody(body io.ReadCloser) {
+	io.Copy(ioutil.Discard, &io.LimitedReader{
+		R: body,
+		N: discardLimit,
+	})
+	body.Close()
+}