CI: move grabpl e2e tests from grabpl to grafana (#53075)

* move grabpl e2e tests

pkg/build/e2eutil/grafana_server.go

@@ -0,0 +1,63 @@
+package e2eutil
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"time"
+)
+
+const timeout = 60
+
+type GrafanaServer struct {
+	Port int
+	Host string
+}
+
+func Server(host string, port int) *GrafanaServer {
+	return &GrafanaServer{
+		Host: host,
+		Port: port,
+	}
+}
+
+func (g *GrafanaServer) Wait() {
+	ticker := time.NewTicker(1 * time.Second)
+	defer ticker.Stop()
+
+	timeoutExceeded := time.After(timeout * time.Second)
+
+	for {
+		select {
+		case <-timeoutExceeded:
+			log.Printf("grafana server failed to start after %d second(s) timeout", timeout)
+			os.Exit(1)
+
+		case <-ticker.C:
+			url := fmt.Sprintf("http://%s:%d", g.Host, g.Port)
+			//nolint:gosec
+			resp, err := http.Get(url)
+			if err == nil {
+				body, err := io.ReadAll(resp.Body)
+				if err != nil {
+					log.Printf("failed to read response body: %q", err)
+					return
+				}
+				log.Println("connected to grafana-server!")
+				if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+					log.Printf("status code: %d, body: %s, exiting...", resp.StatusCode, string(body))
+					os.Exit(1)
+				}
+				err = resp.Body.Close()
+				if err != nil {
+					log.Printf("error closing response body, body: %s", string(body))
+					return
+				}
+				return
+			}
+			log.Printf("failed attempt to connect to grafana-server on url %s, retrying...", url)
+		}
+	}
+}