main: add new --store argument to image-builder build

This commit adds a new `--store` flag to the `image-builder build`
command. This is used to specify a osbuild store directory to
store the intermediate build tree for faster rebuilding. It is
also useful for the container version of `image-builder-cli` to
allow mapping the users store into the container.

cmd/image-builder/build.go

@@ -8,8 +8,7 @@ import (
 	"github.com/osbuild/images/pkg/osbuild"
 )
 
-func buildImage(res *imagefilter.Result, osbuildManifest []byte) error {
+func buildImage(res *imagefilter.Result, osbuildManifest []byte, osbuildStoreDir string) error {
-	osbuildStoreDir := ".store"
 	// XXX: support output dir via commandline
 	// XXX2: support output filename via commandline (c.f.
 	//   https://github.com/osbuild/images/pull/1039)

cmd/image-builder/main.go

@@ -88,8 +88,12 @@ func cmdManifest(cmd *cobra.Command, args []string) error {
 }
 
 func cmdBuild(cmd *cobra.Command, args []string) error {
-	var mf bytes.Buffer
+	storeDir, err := cmd.Flags().GetString("store")
+	if err != nil {
+		return err
+	}
 
+	var mf bytes.Buffer
 	// XXX: check env here, i.e. if user is root and osbuild is installed
 	res, err := cmdManifestWrapper(cmd, args, &mf, func(archStr string) error {
 		if archStr != arch.Current().String() {
@@ -101,7 +105,7 @@ func cmdBuild(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	return buildImage(res, mf.Bytes())
+	return buildImage(res, mf.Bytes(), storeDir)
 }
 
 func run() error {
@@ -154,6 +158,7 @@ operating sytsems like centos and RHEL with easy customizations support.`,
 		Args:         cobra.RangeArgs(1, 2),
 	}
 	buildCmd.Flags().AddFlagSet(manifestCmd.Flags())
+	buildCmd.Flags().String("store", ".store", `osbuild store directory to cache intermediata build artifacts"`)
 	rootCmd.AddCommand(buildCmd)
 
 	return rootCmd.Execute()

cmd/image-builder/main_test.go

@@ -239,11 +239,13 @@ func TestBuildIntegrationHappy(t *testing.T) {
 	restore := main.MockNewRepoRegistry(testrepos.New)
 	defer restore()
 
+	tmpdir := t.TempDir()
 	restore = main.MockOsArgs([]string{
 		"build",
 		"qcow2",
 		makeTestBlueprint(t, testBlueprint),
 		"--distro", "centos-9",
+		"--store", tmpdir,
 	})
 	defer restore()
 
@@ -256,8 +258,12 @@ func TestBuildIntegrationHappy(t *testing.T) {
 
 	// ensure osbuild was run exactly one
 	assert.Equal(t, 1, len(fakeOsbuildCmd.Calls()))
-	// and we passed the output dir
 	osbuildCall := fakeOsbuildCmd.Calls()[0]
+	// --store is passed correctly to osbuild
+	storePos := slices.Index(osbuildCall, "--store")
+	assert.True(t, storePos > -1)
+	assert.Equal(t, tmpdir, osbuildCall[storePos+1])
+	// and we passed the output dir
 	outputDirPos := slices.Index(osbuildCall, "--output-directory")
 	assert.True(t, outputDirPos > -1)
 	assert.Equal(t, "centos-9-qcow2-x86_64", osbuildCall[outputDirPos+1])