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/golangutils/build.go

@@ -0,0 +1,124 @@
+package golangutils
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os/exec"
+	"strings"
+
+	"github.com/grafana/grafana/pkg/build/config"
+)
+
+type BuildOpts struct {
+	// Package refers to the path to the `main` package containing `func main`
+	Package string
+
+	// Output is used as the -o argument in the go build command
+	Output string
+
+	// Workdir should define some place in the module where the package path resolves.
+	// Go commands need to be ran inside a the Go module directory.
+	Workdir string
+
+	GoOS   config.OS
+	GoArch config.Architecture
+	GoArm  string
+	Go386  string
+	CC     string
+	LibC   string
+
+	CGoEnabled bool
+	CGoCFlags  string
+
+	// LdFlags are joined by a space character and provided to the -ldflags argument.
+	// A valid element here would be `-X 'main.version=1.0.0'`.
+	LdFlags []string
+
+	Stdout io.ReadWriter
+	Stderr io.ReadWriter
+	Stdin  io.ReadWriter
+
+	// ExtraEnv allows consumers to provide extra env args that are not defined above.
+	// A single element should be formatted using like so: {NAME}={VALUE}. Example: GOOS=linux.
+	ExtraEnv []string
+
+	// ExtraArgs allows consumers to provide extra arguments that are not defined above.
+	// Flag names and values should be two separate elements.
+	// These flags will be appended to the command arguments before the package path in "go build".
+	ExtraArgs []string
+}
+
+// Env constructs a list of key/value pairs for setting a build command's environment.
+// Should we consider using something to unmarshal the struct to env?
+func (opts BuildOpts) Env() []string {
+	env := []string{}
+	if opts.CGoEnabled {
+		env = append(env, "CGO_ENABLED=1")
+	}
+
+	if opts.GoOS != "" {
+		env = append(env, fmt.Sprintf("GOOS=%s", opts.GoOS))
+	}
+
+	if opts.GoArch != "" {
+		env = append(env, fmt.Sprintf("GOARCH=%s", opts.GoArch))
+	}
+
+	if opts.CC != "" {
+		env = append(env, fmt.Sprintf("CC=%s", opts.CC))
+	}
+
+	if opts.CGoCFlags != "" {
+		env = append(env, fmt.Sprintf("CGO_CFLAGS=%s", opts.CGoCFlags))
+	}
+
+	if opts.GoArm != "" {
+		env = append(env, fmt.Sprintf("GOARM=%s", opts.GoArm))
+	}
+
+	if opts.ExtraEnv != nil {
+		return append(opts.ExtraEnv, env...)
+	}
+
+	return env
+}
+
+// Args constructs a list of flags and values for use with the exec.Command type when running "go build".
+func (opts BuildOpts) Args() []string {
+	args := []string{}
+
+	if opts.LdFlags != nil {
+		args = append(args, "-ldflags", strings.Join(opts.LdFlags, " "))
+	}
+
+	if opts.Output != "" {
+		args = append(args, "-o", opts.Output)
+	}
+
+	if opts.ExtraArgs != nil {
+		args = append(args, opts.ExtraArgs...)
+	}
+
+	args = append(args, opts.Package)
+
+	return args
+}
+
+// Build runs the go build process in the current shell given the opts.
+// This function will panic if no Stdout/Stderr/Stdin is provided in the opts.
+func RunBuild(ctx context.Context, opts BuildOpts) error {
+	env := opts.Env()
+	args := append([]string{"build"}, opts.Args()...)
+	// Ignore gosec G304 as this function is only used in the build process.
+	//nolint:gosec
+	cmd := exec.CommandContext(ctx, "go", args...)
+	cmd.Env = env
+
+	cmd.Stdout = opts.Stdout
+	cmd.Stderr = opts.Stderr
+	cmd.Stdin = opts.Stdin
+	cmd.Dir = opts.Workdir
+
+	return cmd.Run()
+}

pkg/build/golangutils/doc.go

@@ -0,0 +1,2 @@
+// Package golangutils holds utility functions, wrappers, and types for building Go binaries for Grafana.
+package golangutils