CI: add the grabpl build-backend command into the repo (#52673)

* Move the grabpl build-backend command and clean it up a bit

pkg/build/cmd/argcount_wrapper.go

@@ -0,0 +1,16 @@
+package main
+
+import "github.com/urfave/cli/v2"
+
+func ArgCountWrapper(max int, action cli.ActionFunc) cli.ActionFunc {
+	return func(ctx *cli.Context) error {
+		if ctx.NArg() > max {
+			if err := cli.ShowSubcommandHelp(ctx); err != nil {
+				return cli.Exit(err.Error(), 1)
+			}
+			return cli.Exit("", 1)
+		}
+
+		return action(ctx)
+	}
+}

pkg/build/cmd/buildbackend.go

@@ -0,0 +1,78 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"path/filepath"
+	"strings"
+
+	"github.com/urfave/cli/v2"
+
+	"github.com/grafana/grafana/pkg/build/compilers"
+	"github.com/grafana/grafana/pkg/build/config"
+	"github.com/grafana/grafana/pkg/build/errutil"
+	"github.com/grafana/grafana/pkg/build/grafana"
+	"github.com/grafana/grafana/pkg/build/syncutil"
+)
+
+func BuildBackend(ctx *cli.Context) error {
+	metadata, err := config.GetMetadata(filepath.Join("dist", "version.json"))
+	if err != nil {
+		return err
+	}
+
+	var version string
+
+	// ./ci build-backend v1.0.0
+	if ctx.NArg() == 1 {
+		version = strings.TrimPrefix(ctx.Args().Get(0), "v")
+	} else {
+		version = metadata.GrafanaVersion
+	}
+
+	var (
+		edition = config.Edition(ctx.String("edition"))
+		cfg     = config.Config{
+			NumWorkers: ctx.Int("jobs"),
+		}
+	)
+
+	mode, err := config.GetVersion(metadata.ReleaseMode)
+	if err != nil {
+		return fmt.Errorf("could not get version / package info for mode '%s': %w", metadata.ReleaseMode, err)
+	}
+
+	const grafanaDir = "."
+
+	log.Printf("Building Grafana back-end, version %q, %s edition, variants [%v]",
+		version, edition, mode.Variants)
+
+	p := syncutil.NewWorkerPool(cfg.NumWorkers)
+	defer p.Close()
+
+	if err := compilers.Install(); err != nil {
+		return cli.Exit(err.Error(), 1)
+	}
+
+	g, _ := errutil.GroupWithContext(ctx.Context)
+	for _, variant := range mode.Variants {
+		variant := variant
+
+		opts := grafana.BuildVariantOpts{
+			Variant:    variant,
+			Edition:    edition,
+			Version:    version,
+			GrafanaDir: grafanaDir,
+		}
+
+		p.Schedule(g.Wrap(func() error {
+			return grafana.BuildVariant(ctx.Context, opts)
+		}))
+	}
+	if err := g.Wait(); err != nil {
+		return cli.Exit(err.Error(), 1)
+	}
+
+	log.Println("Successfully built back-end binaries!")
+	return nil
+}

pkg/build/cmd/flags.go

@@ -0,0 +1,23 @@
+package main
+
+import "github.com/urfave/cli/v2"
+
+var (
+	jobsFlag = cli.IntFlag{
+		Name:  "jobs",
+		Usage: "Number of parallel jobs",
+	}
+	buildIDFlag = cli.StringFlag{
+		Name:  "build-id",
+		Usage: "Optionally supply a build ID to be part of the version",
+	}
+	editionFlag = cli.StringFlag{
+		Name:  "edition",
+		Usage: "The edition of Grafana to build (oss or enterprise)",
+		Value: "oss",
+	}
+	variantsFlag = cli.StringFlag{
+		Name:  "variants",
+		Usage: "Comma-separated list of variants to build",
+	}
+)

pkg/build/cmd/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/urfave/cli/v2"
+)
+
+func main() {
+	app := cli.NewApp()
+
+	app.Commands = cli.Commands{
+		{
+			Name:      "build-backend",
+			Usage:     "Build one or more variants of back-end binaries",
+			ArgsUsage: "[version]",
+			Action:    ArgCountWrapper(1, BuildBackend),
+			Flags: []cli.Flag{
+				&jobsFlag,
+				&variantsFlag,
+				&editionFlag,
+				&buildIDFlag,
+			},
+		},
+	}
+
+	if err := app.Run(os.Args); err != nil {
+		log.Fatalln(err)
+	}
+}