CI: move grabpl shellcheck from grabpl to grafana (#53076)

* add grabpl shellcheck

* grabpl shellcheck -> ./bin/build shellcheck

pkg/build/cmd/main.go

@@ -24,6 +24,10 @@ func main() {
 			},
 		},
 		{
+			Name:   "shellcheck",
+			Usage:  "Run shellcheck on shell scripts",
+			Action: Shellcheck,
+		}, {
 			Name:   "build-plugins",
 			Usage:  "Build internal plug-ins",
 			Action: ArgCountWrapper(1, BuildInternalPlugins),

pkg/build/cmd/shellcheck.go

@@ -0,0 +1,42 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+
+	"github.com/urfave/cli/v2"
+)
+
+func Shellcheck(c *cli.Context) error {
+	log.Println("Running shellcheck...")
+
+	fpaths := []string{}
+	if err := filepath.Walk("scripts", func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if strings.HasSuffix(path, ".sh") {
+			fpaths = append(fpaths, path)
+		}
+
+		return nil
+	}); err != nil {
+		return fmt.Errorf("couldn't traverse scripts/: %w", err)
+	}
+
+	log.Printf("Running shellcheck on %s", strings.Join(fpaths, ","))
+	args := append([]string{"-e", "SC1071", "-e", "SC2162"}, fpaths...)
+	//nolint:gosec
+	cmd := exec.Command("shellcheck", args...)
+	if output, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("shellcheck failed: %s", output)
+	}
+
+	log.Println("Successfully ran shellcheck!")
+	return nil
+}