distro/rhel84: use a random uuid for XFS partition

Imagine this situation: You have a RHEL system booted from an image produced
by osbuild-composer. On this system, you want to use osbuild-composer to
create another image of RHEL.

However, there's currently something funny with partitions:

All RHEL images built by osbuild-composer contain a root xfs partition. The
interesting bit is that they all share the same xfs partition UUID. This might
sound like a good thing for reproducibility but it has a quirk.

The issue appears when osbuild runs the qemu assembler: it needs to mount all
partitions of the future image to copy the OS tree into it.

Imagine that osbuild-composer is running on a system booted from an imaged
produced by osbuild-composer. This means that its root xfs partition has this
uuid:

efe8afea-c0a8-45dc-8e6e-499279f6fa5d

When osbuild-composer builds an image on this system, it runs osbuild that
runs the qemu assembler at some point. As I said previously, it will mount
all partitions of the future image. That means that it will also try to
mount the root xfs partition with this uuid:

efe8afea-c0a8-45dc-8e6e-499279f6fa5d

Do you remember this one? Yeah, it's the same one as before. However, the xfs
kernel driver doesn't like that. It contains a global table[1] of all xfs
partitions that forbids to mount 2 xfs partitions with the same uuid.

I mean... uuids are meant to be unique, right?

This commit changes the way we build RHEL 8.4 images: Each one now has a
unique uuid. It's now literally a unique universally unique identifier. haha

[1]: https://github.com/torvalds/linux/blob/a349e4c659609fd20e4beea89e5c4a4038e33a95/fs/xfs/xfs_mount.c#L51

cmd/osbuild-pipeline/main.go

@@ -44,6 +44,8 @@ type rpmMD struct {
 func main() {
 	var rpmmdArg bool
 	flag.BoolVar(&rpmmdArg, "rpmmd", false, "output rpmmd struct instead of pipeline manifest")
+	var seedArg int64
+	flag.Int64Var(&seedArg, "seed", 0, "seed for generating manifests (default: 0)")
 	flag.Parse()
 
 	// Path to composeRequet or '-' for stdin
@@ -152,7 +154,8 @@ func main() {
 			},
 			repos,
 			packageSpecs,
-			buildPackageSpecs)
+			buildPackageSpecs,
+			seedArg)
 		if err != nil {
 			panic(err.Error())
 		}

cmd/osbuild-store-dump/main.go

@@ -26,7 +26,7 @@ func getManifest(bp blueprint.Blueprint, t distro.ImageType, a distro.Arch, d di
 	if err != nil {
 		panic(err)
 	}
-	manifest, err := t.Manifest(bp.Customizations, distro.ImageOptions{}, repos, pkgs, buildPkgs)
+	manifest, err := t.Manifest(bp.Customizations, distro.ImageOptions{}, repos, pkgs, buildPkgs, 0)
 	if err != nil {
 		panic(err)
 	}

internal/cloudapi/server.go

@@ -5,6 +5,7 @@ package cloudapi
 import (
 	"encoding/json"
 	"fmt"
+	"math/rand"
 	"net/http"
 
 	"github.com/go-chi/chi"
@@ -81,6 +82,9 @@ func (server *Server) Compose(w http.ResponseWriter, r *http.Request) {
 	imageRequests := make([]imageRequest, len(request.ImageRequests))
 	var targets []*target.Target
 
+	// use the same seed for all images so we get the same IDs
+	manifestSeed := rand.Int63()
+
 	for i, ir := range request.ImageRequests {
 		arch, err := distribution.GetArch(ir.Architecture)
 		if err != nil {
@@ -139,7 +143,7 @@ func (server *Server) Compose(w http.ResponseWriter, r *http.Request) {
 			}
 		}
 
-		manifest, err := imageType.Manifest(nil, imageOptions, repositories, packages, buildPackages)
+		manifest, err := imageType.Manifest(nil, imageOptions, repositories, packages, buildPackages, manifestSeed)
 		if err != nil {
 			http.Error(w, fmt.Sprintf("Failed to get manifest for for %s/%s/%s: %s", ir.ImageType, ir.Architecture, request.Distribution, err), http.StatusBadRequest)
 			return

internal/distro/distro.go

@@ -79,7 +79,7 @@ type ImageType interface {
 	// Returns an osbuild manifest, containing the sources and pipeline necessary
 	// to build an image, given output format with all packages and customizations
 	// specified in the given blueprint.
-	Manifest(b *blueprint.Customizations, options ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec) (Manifest, error)
+	Manifest(b *blueprint.Customizations, options ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec, seed int64) (Manifest, error)
 }
 
 // The ImageOptions specify options for a specific image build

internal/distro/distro_test_common/distro_test_common.go

@@ -16,6 +16,8 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+const RandomTestSeed = 0
+
 func TestDistro_Manifest(t *testing.T, pipelinePath string, prefix string, distros ...distro.Distro) {
 	assert := assert.New(t)
 	fileNames, err := filepath.Glob(filepath.Join(pipelinePath, prefix))
@@ -89,7 +91,8 @@ func TestDistro_Manifest(t *testing.T, pipelinePath string, prefix string, distr
 				},
 				repos,
 				tt.RpmMD.Packages,
-				tt.RpmMD.BuildPackages)
+				tt.RpmMD.BuildPackages,
+				RandomTestSeed)
 
 			if (err == nil && tt.Manifest == nil) || (err != nil && tt.Manifest != nil) {
 				t.Errorf("distro.Manifest() error = %v", err)

internal/distro/fedora32/distro.go

@@ -183,7 +183,8 @@ func (t *imageType) Manifest(c *blueprint.Customizations,
 	options distro.ImageOptions,
 	repos []rpmmd.RepoConfig,
 	packageSpecs,
-	buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
+	buildPackageSpecs []rpmmd.PackageSpec,
+	seed int64) (distro.Manifest, error) {
 	pipeline, err := t.pipeline(c, options, repos, packageSpecs, buildPackageSpecs)
 	if err != nil {
 		return distro.Manifest{}, err

internal/distro/fedora33/distro.go

@@ -183,7 +183,8 @@ func (t *imageType) Manifest(c *blueprint.Customizations,
 	options distro.ImageOptions,
 	repos []rpmmd.RepoConfig,
 	packageSpecs,
-	buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
+	buildPackageSpecs []rpmmd.PackageSpec,
+	seed int64) (distro.Manifest, error) {
 	pipeline, err := t.pipeline(c, options, repos, packageSpecs, buildPackageSpecs)
 	if err != nil {
 		return distro.Manifest{}, err

internal/distro/fedoratest/distro.go

@@ -95,7 +95,8 @@ func (t *imageType) Manifest(c *blueprint.Customizations,
 	options distro.ImageOptions,
 	repos []rpmmd.RepoConfig,
 	packageSpecs,
-	buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
+	buildPackageSpecs []rpmmd.PackageSpec,
+	seed int64) (distro.Manifest, error) {
 
 	return json.Marshal(
 		osbuild.Manifest{

internal/distro/rhel8/distro.go

@@ -185,7 +185,8 @@ func (t *imageType) Manifest(c *blueprint.Customizations,
 	options distro.ImageOptions,
 	repos []rpmmd.RepoConfig,
 	packageSpecs,
-	buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
+	buildPackageSpecs []rpmmd.PackageSpec,
+	seed int64) (distro.Manifest, error) {
 	pipeline, err := t.pipeline(c, options, repos, packageSpecs, buildPackageSpecs)
 	if err != nil {
 		return distro.Manifest{}, err

internal/distro/rhel84/distro.go

@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
+	"math/rand"
 	"sort"
 
 	"github.com/osbuild/osbuild-composer/internal/disk"
@@ -50,7 +52,7 @@ type imageType struct {
 	bootable                bool
 	rpmOstree               bool
 	defaultSize             uint64
-	partitionTableGenerator func(imageOptions distro.ImageOptions, arch distro.Arch) disk.PartitionTable
+	partitionTableGenerator func(imageOptions distro.ImageOptions, arch distro.Arch, rng *rand.Rand) disk.PartitionTable
 	assembler               func(pt *disk.PartitionTable, options distro.ImageOptions, arch distro.Arch) *osbuild.Assembler
 }
 
@@ -188,8 +190,11 @@ func (t *imageType) Manifest(c *blueprint.Customizations,
 	options distro.ImageOptions,
 	repos []rpmmd.RepoConfig,
 	packageSpecs,
-	buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
-	pipeline, err := t.pipeline(c, options, repos, packageSpecs, buildPackageSpecs)
+	buildPackageSpecs []rpmmd.PackageSpec,
+	seed int64) (distro.Manifest, error) {
+	source := rand.NewSource(seed)
+	rng := rand.New(source)
+	pipeline, err := t.pipeline(c, options, repos, packageSpecs, buildPackageSpecs, rng)
 	if err != nil {
 		return distro.Manifest{}, err
 	}
@@ -230,10 +235,10 @@ func sources(packages []rpmmd.PackageSpec) *osbuild.Sources {
 	}
 }
 
-func (t *imageType) pipeline(c *blueprint.Customizations, options distro.ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec) (*osbuild.Pipeline, error) {
+func (t *imageType) pipeline(c *blueprint.Customizations, options distro.ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec, rng *rand.Rand) (*osbuild.Pipeline, error) {
 	var pt *disk.PartitionTable
 	if t.partitionTableGenerator != nil {
-		table := t.partitionTableGenerator(options, t.arch)
+		table := t.partitionTableGenerator(options, t.arch, rng)
 		pt = &table
 	}
 
@@ -497,7 +502,7 @@ func (t *imageType) selinuxStageOptions() *osbuild.SELinuxStageOptions {
 	}
 }
 
-func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch) disk.PartitionTable {
+func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch, rng *rand.Rand) disk.PartitionTable {
 	if arch.Name() == "x86_64" {
 		return disk.PartitionTable{
 			Size: imageOptions.Size,
@@ -531,7 +536,7 @@ func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch) d
 					UUID:  "6264D520-3FB9-423F-8AB8-7A0A8E3D3562",
 					Filesystem: &disk.Filesystem{
 						Type:         "xfs",
-						UUID:         "efe8afea-c0a8-45dc-8e6e-499279f6fa5d",
+						UUID:         uuid.Must(newRandomUUIDFromReader(rng)).String(),
 						Label:        "root",
 						Mountpoint:   "/",
 						FSTabOptions: "defaults",
@@ -567,7 +572,7 @@ func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch) d
 					UUID:  "6264D520-3FB9-423F-8AB8-7A0A8E3D3562",
 					Filesystem: &disk.Filesystem{
 						Type:         "xfs",
-						UUID:         "efe8afea-c0a8-45dc-8e6e-499279f6fa5d",
+						UUID:         uuid.Must(newRandomUUIDFromReader(rng)).String(),
 						Label:        "root",
 						Mountpoint:   "/",
 						FSTabOptions: "defaults",
@@ -592,7 +597,7 @@ func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch) d
 					Start: 10240,
 					Filesystem: &disk.Filesystem{
 						Type:         "xfs",
-						UUID:         "efe8afea-c0a8-45dc-8e6e-499279f6fa5d",
+						UUID:         uuid.Must(newRandomUUIDFromReader(rng)).String(),
 						Mountpoint:   "/",
 						FSTabOptions: "defaults",
 						FSTabFreq:    0,
@@ -612,7 +617,7 @@ func defaultPartitionTable(imageOptions distro.ImageOptions, arch distro.Arch) d
 					Bootable: true,
 					Filesystem: &disk.Filesystem{
 						Type:         "xfs",
-						UUID:         "efe8afea-c0a8-45dc-8e6e-499279f6fa5d",
+						UUID:         uuid.Must(newRandomUUIDFromReader(rng)).String(),
 						Mountpoint:   "/",
 						FSTabOptions: "defaults",
 						FSTabFreq:    0,
@@ -673,6 +678,17 @@ func ostreeCommitAssembler(options distro.ImageOptions, arch distro.Arch) *osbui
 	)
 }
 
+func newRandomUUIDFromReader(r io.Reader) (uuid.UUID, error) {
+	var id uuid.UUID
+	_, err := io.ReadFull(r, id[:])
+	if err != nil {
+		return uuid.Nil, err
+	}
+	id[6] = (id[6] & 0x0f) | 0x40 // Version 4
+	id[8] = (id[8] & 0x3f) | 0x80 // Variant is 10
+	return id, nil
+}
+
 // New creates a new distro object, defining the supported architectures and image types
 func New() distro.Distro {
 	const GigaByte = 1024 * 1024 * 1024

internal/distro/test_distro/distro.go

@@ -75,7 +75,7 @@ func (t *TestImageType) BuildPackages() []string {
 	return nil
 }
 
-func (t *TestImageType) Manifest(b *blueprint.Customizations, options distro.ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec) (distro.Manifest, error) {
+func (t *TestImageType) Manifest(b *blueprint.Customizations, options distro.ImageOptions, repos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec, seed int64) (distro.Manifest, error) {
 	return json.Marshal(
 		osbuild.Manifest{
 			Sources:  osbuild.Sources{},

internal/kojiapi/server.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"math/rand"
 	"net/http"
 	"strings"
 	"time"
@@ -87,6 +88,9 @@ func (h *apiHandlers) PostCompose(ctx echo.Context) error {
 	kojiFilenames := make([]string, len(request.ImageRequests))
 	kojiDirectory := "osbuild-composer-koji-" + uuid.New().String()
 
+	// use the same seed for all images so we get the same IDs
+	manifestSeed := rand.Int63()
+
 	for i, ir := range request.ImageRequests {
 		arch, err := d.GetArch(ir.Architecture)
 		if err != nil {
@@ -119,7 +123,7 @@ func (h *apiHandlers) PostCompose(ctx echo.Context) error {
 			return echo.NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Failed to depsolve build packages for %s/%s/%s: %s", ir.ImageType, ir.Architecture, request.Distribution, err))
 		}
 
-		manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, repositories, packages, buildPackages)
+		manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, repositories, packages, buildPackages, manifestSeed)
 		if err != nil {
 			return echo.NewHTTPError(http.StatusBadGateway, fmt.Sprintf("Failed to get manifest for for %s/%s/%s: %s", ir.ImageType, ir.Architecture, request.Distribution, err))
 		}

internal/store/fixtures.go

@@ -57,7 +57,7 @@ func FixtureBase() *Store {
 	if err != nil {
 		panic("invalid image type qcow2 for x86_64 @ fedoratest")
 	}
-	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil)
+	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil, 0)
 	if err != nil {
 		panic("could not create manifest")
 	}
@@ -160,7 +160,7 @@ func FixtureFinished() *Store {
 	if err != nil {
 		panic("invalid image type qcow2 for x86_64 @ fedoratest")
 	}
-	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil)
+	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil, 0)
 	if err != nil {
 		panic("could not create manifest")
 	}

internal/store/store_test.go

@@ -51,7 +51,7 @@ func (suite *storeTest) SetupSuite() {
 	suite.myDistro = test_distro.New()
 	suite.myArch, _ = suite.myDistro.GetArch("test_arch")
 	suite.myImageType, _ = suite.myArch.GetImageType("test_type")
-	suite.myManifest, _ = suite.myImageType.Manifest(&suite.myCustomizations, suite.myImageOptions, suite.myRepoConfig, nil, suite.myPackageSpec)
+	suite.myManifest, _ = suite.myImageType.Manifest(&suite.myCustomizations, suite.myImageOptions, suite.myRepoConfig, nil, suite.myPackageSpec, 0)
 	suite.mySourceConfig = SourceConfig{
 		Name: "testSourceConfig",
 	}

internal/weldr/api.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"math/rand"
 	"net"
 	"net/http"
 	"net/url"
@@ -1846,7 +1847,8 @@ func (api *API) composeHandler(writer http.ResponseWriter, request *http.Request
 		},
 		api.allRepositories(),
 		packages,
-		buildPackages)
+		buildPackages,
+		rand.Int63())
 	if err != nil {
 		errors := responseError{
 			ID:  "ManifestCreationFailed",

internal/weldr/api_test.go

@@ -461,7 +461,7 @@ func TestCompose(t *testing.T) {
 	require.NoError(t, err)
 	imgType, err := arch.GetImageType("qcow2")
 	require.NoError(t, err)
-	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil)
+	manifest, err := imgType.Manifest(nil, distro.ImageOptions{}, nil, nil, nil, 0)
 	require.NoError(t, err)
 	expectedComposeLocal := &store.Compose{
 		Blueprint: &blueprint.Blueprint{

internal/worker/server_test.go

@@ -60,7 +60,7 @@ func TestCreate(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting image type from arch")
 	}
-	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil)
+	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil, 0)
 	if err != nil {
 		t.Fatalf("error creating osbuild manifest")
 	}
@@ -84,7 +84,7 @@ func TestCancel(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting image type from arch")
 	}
-	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil)
+	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil, 0)
 	if err != nil {
 		t.Fatalf("error creating osbuild manifest")
 	}
@@ -121,7 +121,7 @@ func TestUpdate(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting image type from arch")
 	}
-	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil)
+	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil, 0)
 	if err != nil {
 		t.Fatalf("error creating osbuild manifest")
 	}
@@ -152,7 +152,7 @@ func TestUpload(t *testing.T) {
 	if err != nil {
 		t.Fatalf("error getting image type from arch")
 	}
-	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil)
+	manifest, err := imageType.Manifest(nil, distro.ImageOptions{Size: imageType.Size(0)}, nil, nil, nil, 0)
 	if err != nil {
 		t.Fatalf("error creating osbuild manifest")
 	}