CI: move grabpl build-plugins from grabpl to grafana (#53071)

* add grabpl command to build internal plugins

* grabpl build-plugins -> ./bin/build build-plugins

pkg/build/config/version.go

@@ -5,8 +5,12 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
 )
 
 type Metadata struct {
@@ -83,5 +87,77 @@ func GetVersion(mode VersionMode) (*Version, error) {
 		return &v, nil
 	}
 
-	return nil, fmt.Errorf("mode not found in version list")
+	return nil, fmt.Errorf("mode '%s' not found in version list", mode)
+}
+
+func shortenBuildID(buildID string) string {
+	buildID = strings.ReplaceAll(buildID, "-", "")
+	if len(buildID) < 9 {
+		return buildID
+	}
+
+	return buildID[0:8]
+}
+
+// GetGrafanaVersion gets the Grafana version from the package.json
+func GetGrafanaVersion(buildID, grafanaDir string) (string, error) {
+	pkgJSONPath := filepath.Join(grafanaDir, "package.json")
+	//nolint:gosec
+	pkgJSONB, err := ioutil.ReadFile(pkgJSONPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to read %q: %w", pkgJSONPath, err)
+	}
+	pkgObj := map[string]interface{}{}
+	if err := json.Unmarshal(pkgJSONB, &pkgObj); err != nil {
+		return "", fmt.Errorf("failed decoding %q: %w", pkgJSONPath, err)
+	}
+
+	version := pkgObj["version"].(string)
+	if version == "" {
+		return "", fmt.Errorf("failed to read version from %q", pkgJSONPath)
+	}
+	if buildID != "" {
+		buildID = shortenBuildID(buildID)
+		verComponents := strings.Split(version, "-")
+		version = verComponents[0]
+		if len(verComponents) > 1 {
+			buildID = fmt.Sprintf("%s%s", buildID, verComponents[1])
+		}
+		version = fmt.Sprintf("%s-%s", version, buildID)
+	}
+
+	return version, nil
+}
+
+func CheckDroneTargetBranch() (VersionMode, error) {
+	reRlsBranch := regexp.MustCompile(`^v\d+\.\d+\.x$`)
+	target := os.Getenv("DRONE_TARGET_BRANCH")
+	if target == "" {
+		return "", fmt.Errorf("failed to get DRONE_TARGET_BRANCH environmental variable")
+	} else if target == string(MainMode) {
+		return MainMode, nil
+	}
+	if reRlsBranch.MatchString(target) {
+		return ReleaseBranchMode, nil
+	}
+	return "", fmt.Errorf("unrecognized target branch: %s", target)
+}
+
+func CheckSemverSuffix() (VersionMode, error) {
+	reBetaRls := regexp.MustCompile(`beta.*`)
+	reTestRls := regexp.MustCompile(`test.*`)
+	tagSuffix, ok := os.LookupEnv("DRONE_SEMVER_PRERELEASE")
+	if !ok || tagSuffix == "" {
+		fmt.Println("DRONE_SEMVER_PRERELEASE doesn't exist for a tag, this is a release event...")
+		return ReleaseMode, nil
+	}
+	switch {
+	case reBetaRls.MatchString(tagSuffix):
+		return BetaReleaseMode, nil
+	case reTestRls.MatchString(tagSuffix):
+		return TestReleaseMode, nil
+	default:
+		fmt.Printf("DRONE_SEMVER_PRERELEASE is custom string, release event with %s suffix\n", tagSuffix)
+		return ReleaseMode, nil
+	}
 }