weldr: get repositories from distro

Make distros export repository information and use those in the weldr
API. This means that repos are only specified once and that the API
returns the right packages when we allow different distros.

internal/distro/distro.go

@@ -10,9 +10,14 @@ import (
 
 	"github.com/osbuild/osbuild-composer/internal/blueprint"
 	"github.com/osbuild/osbuild-composer/internal/pipeline"
+	"github.com/osbuild/osbuild-composer/internal/rpmmd"
 )
 
 type Distro interface {
+	// Returns a list of repositories from which this distribution gets its
+	// content.
+	Repositories() []rpmmd.RepoConfig
+
 	// Returns a sorted list of the output formats this distro supports.
 	ListOutputFormats() []string
 

internal/distro/fedora30/os.go

@@ -6,6 +6,7 @@ import (
 	"github.com/osbuild/osbuild-composer/internal/blueprint"
 	"github.com/osbuild/osbuild-composer/internal/distro"
 	"github.com/osbuild/osbuild-composer/internal/pipeline"
+	"github.com/osbuild/osbuild-composer/internal/rpmmd"
 )
 
 type Fedora30 struct {
@@ -34,6 +35,16 @@ func init() {
 	})
 }
 
+func (f *Fedora30) Repositories() []rpmmd.RepoConfig {
+	return []rpmmd.RepoConfig{
+		{
+			Id:       "fedora",
+			Name:     "Fedora 30",
+			Metalink: "https://mirrors.fedoraproject.org/metalink?repo=fedora-30&arch=x86_64",
+		},
+	}
+}
+
 // ListOutputFormats returns a sorted list of the supported output formats
 func (f *Fedora30) ListOutputFormats() []string {
 	formats := make([]string, 0, len(f.outputs))

internal/distro/test/distro.go

@@ -0,0 +1,36 @@
+package test
+
+import (
+	"github.com/osbuild/osbuild-composer/internal/blueprint"
+	"github.com/osbuild/osbuild-composer/internal/distro"
+	"github.com/osbuild/osbuild-composer/internal/pipeline"
+	"github.com/osbuild/osbuild-composer/internal/rpmmd"
+)
+
+type TestDistro struct{}
+
+func init() {
+	distro.Register("test", &TestDistro{})
+}
+
+func (d *TestDistro) Repositories() []rpmmd.RepoConfig {
+	return []rpmmd.RepoConfig{
+		{
+			Id:      "test",
+			Name:    "Test",
+			BaseURL: "http://example.com/test/os",
+		},
+	}
+}
+
+func (d *TestDistro) ListOutputFormats() []string {
+	return []string{}
+}
+
+func (d *TestDistro) FilenameFromType(outputFormat string) (string, string, error) {
+	return "", "", &distro.InvalidOutputFormatError{outputFormat}
+}
+
+func (d *TestDistro) Pipeline(b *blueprint.Blueprint, outputFormat string) (*pipeline.Pipeline, error) {
+	return nil, &distro.InvalidOutputFormatError{outputFormat}
+}