manifest: ensure /var/roothome is available when needed

Currently creating a customization for the root user does not work
because `/var/roothome` may not be avaialble in the image. This
commit ensures it is created if needed just like we do for `/var/home`.

Closes osbuild/bootc-image-builder#143

pkg/manifest/raw_bootc.go

@@ -85,6 +85,39 @@ func (p *RawBootcImage) serializeEnd() {
 	p.containerSpecs = nil
 }
 
+func buildHomedirPaths(users []users.User) []osbuild.MkdirStagePath {
+	var containsRootUser, containsNormalUser bool
+
+	for _, user := range users {
+		if user.Name == "root" {
+			containsRootUser = true
+		} else {
+			containsNormalUser = true
+		}
+	}
+
+	rootHomePath := osbuild.MkdirStagePath{
+		Path:    "/var/roothome",
+		Mode:    common.ToPtr(os.FileMode(0700)),
+		ExistOk: true,
+	}
+	userHomePath := osbuild.MkdirStagePath{
+		Path:    "/var/home",
+		Mode:    common.ToPtr(os.FileMode(0755)),
+		ExistOk: true,
+	}
+	switch {
+	case containsRootUser && containsNormalUser:
+		return []osbuild.MkdirStagePath{rootHomePath, userHomePath}
+	case containsRootUser:
+		return []osbuild.MkdirStagePath{rootHomePath}
+	case containsNormalUser:
+		return []osbuild.MkdirStagePath{userHomePath}
+	default:
+		return nil
+	}
+}
+
 func (p *RawBootcImage) serialize() osbuild.Pipeline {
 	pipeline := p.Base.serialize()
 
@@ -148,16 +181,12 @@ func (p *RawBootcImage) serialize() osbuild.Pipeline {
 		groupsStage.Devices = devices
 		pipeline.AddStage(groupsStage)
 	}
+
 	if len(p.Users) > 0 {
-		// ensure /var/home is available
+		// ensure home root dir (currently /var/home, /var/roothome) is
+		// available
 		mkdirStage := osbuild.NewMkdirStage(&osbuild.MkdirStageOptions{
-			Paths: []osbuild.MkdirStagePath{
-				{
-					Path:    "/var/home",
-					Mode:    common.ToPtr(os.FileMode(0755)),
-					ExistOk: true,
-				},
-			},
+			Paths: buildHomedirPaths(p.Users),
 		})
 		mkdirStage.Mounts = mounts
 		mkdirStage.Devices = devices

pkg/manifest/raw_bootc_test.go

@@ -1,6 +1,7 @@
 package manifest_test
 
 import (
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -132,6 +133,46 @@ func TestRawBootcImageSerializeCreateUsersOptions(t *testing.T) {
 	}
 }
 
+func TestRawBootcImageSerializeMkdirOptions(t *testing.T) {
+	rawBootcPipeline := makeFakeRawBootcPipeline()
+
+	for _, tc := range []struct {
+		users              []users.User
+		expectedMkdirPaths []osbuild.MkdirStagePath
+	}{
+		{nil, nil},
+		{
+			[]users.User{{Name: "root"}}, []osbuild.MkdirStagePath{
+				{Path: "/var/roothome", Mode: common.ToPtr(os.FileMode(0700)), ExistOk: true},
+			},
+		},
+		{
+			[]users.User{{Name: "foo"}}, []osbuild.MkdirStagePath{
+				{Path: "/var/home", Mode: common.ToPtr(os.FileMode(0755)), ExistOk: true},
+			},
+		},
+		{
+			[]users.User{{Name: "root"}, {Name: "foo"}}, []osbuild.MkdirStagePath{
+				{Path: "/var/roothome", Mode: common.ToPtr(os.FileMode(0700)), ExistOk: true},
+				{Path: "/var/home", Mode: common.ToPtr(os.FileMode(0755)), ExistOk: true},
+			},
+		},
+	} {
+		rawBootcPipeline.Users = tc.users
+
+		pipeline := rawBootcPipeline.Serialize()
+		mkdirStage := manifest.FindStage("org.osbuild.mkdir", pipeline.Stages)
+		if len(tc.expectedMkdirPaths) > 0 {
+			// ensure options got passed
+			require.NotNil(t, mkdirStage)
+			mkdirOptions := mkdirStage.Options.(*osbuild.MkdirStageOptions)
+			assert.Equal(t, tc.expectedMkdirPaths, mkdirOptions.Paths)
+		} else {
+			require.Nil(t, mkdirStage)
+		}
+	}
+}
+
 func TestRawBootcImageSerializeCreateGroupOptions(t *testing.T) {
 	rawBootcPipeline := makeFakeRawBootcPipeline()