CI: move grabpl build-frontend from grabpl to grafana (#53073)

* move grabpl build-frontend

pkg/build/frontend/build.go

@@ -0,0 +1,42 @@
+package frontend
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/grafana/grafana/pkg/build/config"
+	"github.com/grafana/grafana/pkg/build/errutil"
+	"github.com/grafana/grafana/pkg/build/syncutil"
+)
+
+// Build builds the Grafana front-end
+func Build(edition config.Edition, grafanaDir string, p syncutil.WorkerPool, g *errutil.Group) error {
+	log.Printf("Building %s frontend in %q", edition, grafanaDir)
+	grafanaDir, err := filepath.Abs(grafanaDir)
+	if err != nil {
+		return err
+	}
+
+	for _, dpath := range []string{"tmp", "public_gen", "public/build"} {
+		dpath = filepath.Join(grafanaDir, dpath)
+		if err := os.RemoveAll(dpath); err != nil {
+			return fmt.Errorf("failed to remove %q: %w", dpath, err)
+		}
+	}
+
+	p.Schedule(g.Wrap(func() error {
+		cmd := exec.Command("yarn", "run", "build")
+		cmd.Dir = grafanaDir
+		if output, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("failed to build %s frontend with webpack: %s", edition, output)
+		}
+
+		log.Printf("Finished building %s frontend", edition)
+		return nil
+	}))
+
+	return nil
+}

pkg/build/frontend/config.go

@@ -0,0 +1,30 @@
+package frontend
+
+import (
+	"github.com/grafana/grafana/pkg/build/config"
+	"github.com/urfave/cli/v2"
+)
+
+const GrafanaDir = "."
+
+func GetConfig(c *cli.Context, version string) (config.Config, config.Edition, error) {
+	cfg := config.Config{
+		NumWorkers:     c.Int("jobs"),
+		GitHubToken:    c.String("github-token"),
+		PackageVersion: version,
+	}
+
+	mode := config.Edition(c.String("edition"))
+
+	if version == "" {
+		buildID := c.String("build-id")
+		var err error
+		version, err = config.GetGrafanaVersion(buildID, GrafanaDir)
+		cfg.PackageVersion = version
+		if err != nil {
+			return config.Config{}, config.EditionOSS, cli.Exit(err.Error(), 1)
+		}
+	}
+
+	return cfg, mode, nil
+}