distro: add a Sources method

This outputs the sources needed for the pipeline generated for the
distro. At the moment no pipelines require sources, and so this
always returns the empty list.

Signed-off-by: Tom Gundersen <teg@jklm.no>

internal/distro/distro.go

@@ -55,6 +55,10 @@ type Distro interface {
 	// given blueprint.
 	Pipeline(b *blueprint.Blueprint, additionalRepos []rpmmd.RepoConfig, packageSpecs, buildPackageSpecs []rpmmd.PackageSpec, checksums map[string]string, outputArchitecture, outputFormat string, size uint64) (*osbuild.Pipeline, error)
 
+	// Returns an osbuild sources object that is required for building the
+	// corresponding pipeline containing the given packages.
+	Sources(packages []rpmmd.PackageSpec) *osbuild.Sources
+
 	// Returns a osbuild runner that can be used on this distro.
 	Runner() string
 }

internal/distro/fedora30/distro.go

@@ -469,6 +469,10 @@ func (r *Fedora30) Pipeline(b *blueprint.Blueprint, additionalRepos []rpmmd.Repo
 	return p, nil
 }
 
+func (r *Fedora30) Sources(packages []rpmmd.PackageSpec) *osbuild.Sources {
+	return &osbuild.Sources{}
+}
+
 func (r *Fedora30) Runner() string {
 	return "org.osbuild.fedora30"
 }

internal/distro/fedoratest/distro.go

@@ -71,6 +71,10 @@ func (d *FedoraTestDistro) Pipeline(b *blueprint.Blueprint, additionalRepos []rp
 	}
 }
 
+func (r *FedoraTestDistro) Sources(packages []rpmmd.PackageSpec) *osbuild.Sources {
+	return &osbuild.Sources{}
+}
+
 func (d *FedoraTestDistro) Runner() string {
 	return "org.osbuild.test"
 }

internal/distro/rhel82/distro.go

@@ -612,6 +612,10 @@ func (r *RHEL82) Pipeline(b *blueprint.Blueprint, additionalRepos []rpmmd.RepoCo
 	return p, nil
 }
 
+func (r *RHEL82) Sources(packages []rpmmd.PackageSpec) *osbuild.Sources {
+	return &osbuild.Sources{}
+}
+
 func (r *RHEL82) Runner() string {
 	return "org.osbuild.rhel82"
 }

internal/distro/test/distro.go

@@ -63,6 +63,10 @@ func (d *TestDistro) Pipeline(b *blueprint.Blueprint, additionalRepos []rpmmd.Re
 	return nil, errors.New("invalid output format or arch: " + outputFormat + " @ " + outputArch)
 }
 
+func (d *TestDistro) Sources(packages []rpmmd.PackageSpec) *osbuild.Sources {
+	return &osbuild.Sources{}
+}
+
 func (d *TestDistro) Runner() string {
 	return "org.osbuild.test"
 }