Write update metadata to output directory

Instead of requiring the new swupd code to create the "format" and
"swupd-server-src-version" metadata files enable BuildUpdate to do so.

Because the mixer version is now used instead of a swupd-server version
write the mixer-tools version to a "mixer-src-version" file. Move the
Version const to builder.go so it can be accessed trivially. Update the
Makefile parsing to point to builder.go and update the access method in
the top-level mixer/cmd/root.go.

Signed-off-by: Matthew Johnson <matthew.johnson@intel.com>

Makefile

@@ -77,7 +77,7 @@ release:
 		echo "Release needs to be used from a git repository"; \
 		exit 1; \
 	fi
-	@VERSION=$$(grep -e 'const Version' mixer/cmd/root.go | cut -d '"' -f 2) ; \
+	@VERSION=$$(grep -e 'const Version' builder/builder.go | cut -d '"' -f 2) ; \
 	if [ -z "$$VERSION" ]; then \
 		echo "Couldn't extract version number from the source code"; \
 		exit 1; \

builder/builder.go

@@ -35,6 +35,9 @@ import (
 	"github.com/pkg/errors"
 )
 
+// Version of Mixer. Also used by the Makefile for releases.
+const Version = "3.2.1"
+
 // UseNewSwupdServer controls whether to use the new implementation of
 // swupd-server (package swupd) when possible. This is an experimental feature.
 var UseNewSwupdServer = false
@@ -643,6 +646,10 @@ func (b *Builder) BuildUpdate(prefixflag string, minVersion int, format string,
 func (b *Builder) buildUpdateWithNewSwupd(timer *stopWatch, mixVersion uint32, minVersion uint32, format uint32, skipSigning bool) error {
 	var err error
 
+	err = writeMetaFiles(filepath.Join(b.Statedir, "www", b.Mixver), b.Format, Version)
+	if err != nil {
+		return errors.Wrapf(err, "failed to write update metadata files")
+	}
 	timer.Start("CREATE MANIFESTS")
 	mom, err := swupd.CreateManifests(mixVersion, minVersion, uint(format), b.Statedir)
 	if err != nil {
@@ -1062,3 +1069,18 @@ func createDeltaPacks(from *swupd.Manifest, to *swupd.Manifest, outputDir, chroo
 	}
 	return nil
 }
+
+// writeMetaFiles writes mixer and format metadata to files
+func writeMetaFiles(path, format, version string) error {
+	err := os.MkdirAll(path, 0777)
+	if err != nil {
+		return err
+	}
+
+	err = ioutil.WriteFile(filepath.Join(path, "format"), []byte(format), 0644)
+	if err != nil {
+		return err
+	}
+
+	return ioutil.WriteFile(filepath.Join(path, "mixer-src-version"), []byte(version), 0644)
+}

mixer/cmd/root.go

@@ -29,9 +29,6 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// Version of Mixer. Also used by the Makefile for releases.
-const Version = "3.2.1"
-
 var config string
 
 // RootCmd represents the base command when called without any subcommands
@@ -54,7 +51,7 @@ var RootCmd = &cobra.Command{
 		// check for external programs.
 		if cmd.Parent() == nil { // This is RootCmd.
 			if rootCmdFlags.version {
-				fmt.Printf("Mixer %s\n", Version)
+				fmt.Printf("Mixer %s\n", builder.Version)
 				os.Exit(0)
 			}
 			if rootCmdFlags.check {