manifest: implement serializeStart() for ostree pipelines

Pipelines that don't require packages didn't need to implement the
serializeStart() method, but now we need to set the resolved ostree
commit spec when a pipelines requires it.

internal/manifest/iso_tree.go

@@ -4,9 +4,11 @@ import (
 	"fmt"
 	"path"
 
+	"github.com/osbuild/osbuild-composer/internal/container"
 	"github.com/osbuild/osbuild-composer/internal/disk"
 	"github.com/osbuild/osbuild-composer/internal/osbuild"
 	"github.com/osbuild/osbuild-composer/internal/ostree"
+	"github.com/osbuild/osbuild-composer/internal/rpmmd"
 	"github.com/osbuild/osbuild-composer/internal/users"
 )
 
@@ -73,7 +75,6 @@ func NewAnacondaISOTree(m *Manifest,
 	return p
 }
 
-// Return the ostree commit URL and checksum that will be included in this
 func (p *AnacondaISOTree) getOSTreeCommits() []ostree.CommitSpec {
 	if p.OSTree == nil {
 		return nil
@@ -100,6 +101,23 @@ func (p *AnacondaISOTree) getBuildPackages() []string {
 	return packages
 }
 
+func (p *AnacondaISOTree) serializeStart(_ []rpmmd.PackageSpec, _ []container.Spec, commits []ostree.CommitSpec) {
+	if len(commits) == 0 {
+		// nothing to do
+		return
+	}
+
+	if len(commits) > 1 {
+		panic("pipeline supports at most one ostree commit")
+	}
+
+	p.OSTree = &commits[0]
+}
+
+func (p *AnacondaISOTree) serializeEnd() {
+	p.OSTree = nil
+}
+
 func (p *AnacondaISOTree) serialize() osbuild.Pipeline {
 	// We need one of two payloads
 	if p.OSTree == nil && p.OSPipeline == nil {

internal/manifest/os.go

@@ -147,11 +147,14 @@ type OS struct {
 	// Partition table, if nil the tree cannot be put on a partitioned disk
 	PartitionTable *disk.PartitionTable
 
+	// content-related fields
 	repos          []rpmmd.RepoConfig
 	packageSpecs   []rpmmd.PackageSpec
 	containerSpecs []container.Spec
-	platform       platform.Platform
-	kernelVer      string
+	ostreeSpecs    []ostree.CommitSpec
+
+	platform  platform.Platform
+	kernelVer string
 
 	// NoBLS configures the image bootloader with traditional menu entries
 	// instead of BLS. Required for legacy systems like RHEL 7.
@@ -298,6 +301,7 @@ func (p *OS) serializeStart(packages []rpmmd.PackageSpec, containers []container
 
 	p.packageSpecs = packages
 	p.containerSpecs = containers
+	p.ostreeSpecs = commits
 
 	if p.KernelName != "" {
 		p.kernelVer = rpmmd.GetVerStrFromPackageSpecListPanic(p.packageSpecs, p.KernelName)
@@ -311,6 +315,7 @@ func (p *OS) serializeEnd() {
 	p.kernelVer = ""
 	p.packageSpecs = nil
 	p.containerSpecs = nil
+	p.ostreeSpecs = nil
 }
 
 func (p *OS) serialize() osbuild.Pipeline {

internal/manifest/ostree_deployment.go

@@ -5,11 +5,13 @@ import (
 	"strings"
 
 	"github.com/osbuild/osbuild-composer/internal/common"
+	"github.com/osbuild/osbuild-composer/internal/container"
 	"github.com/osbuild/osbuild-composer/internal/disk"
 	"github.com/osbuild/osbuild-composer/internal/fsnode"
 	"github.com/osbuild/osbuild-composer/internal/osbuild"
 	"github.com/osbuild/osbuild-composer/internal/ostree"
 	"github.com/osbuild/osbuild-composer/internal/platform"
+	"github.com/osbuild/osbuild-composer/internal/rpmmd"
 	"github.com/osbuild/osbuild-composer/internal/users"
 )
 
@@ -81,7 +83,31 @@ func (p *OSTreeDeployment) getOSTreeCommits() []ostree.CommitSpec {
 	return []ostree.CommitSpec{p.commit}
 }
 
+func (p *OSTreeDeployment) serializeStart(packages []rpmmd.PackageSpec, containers []container.Spec, commits []ostree.CommitSpec) {
+	if p.commit.Ref != "" {
+		panic("double call to serializeStart()")
+	}
+
+	if len(commits) != 1 {
+		panic("pipeline requires exactly one ostree commit")
+	}
+
+	p.commit = commits[0]
+}
+
+func (p *OSTreeDeployment) serializeEnd() {
+	if p.commit.Ref == "" {
+		panic("serializeEnd() call when serialization not in progress")
+	}
+
+	p.commit = ostree.CommitSpec{}
+}
+
 func (p *OSTreeDeployment) serialize() osbuild.Pipeline {
+	if p.commit.Ref == "" {
+		panic("serialization not started")
+	}
+
 	const repoPath = "/ostree/repo"
 
 	pipeline := p.Base.serialize()