Add mixer repo set-url capability

'mixer repo set-url' allows the user to set the url of a RPM repo to the
url they provide. This is helpful when users want to build mixes off a
mirror of upstream Clear Linux instead of the CDN when the CDN is slow.

mixer repo set-url clear <mirror-url>

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

builder/builder.go

@@ -1663,14 +1663,14 @@ gpgcheck=0
 priority=1
 `
 
-// AddRepo adds and enables a repo configuration named repoInfo[0] pointing at
-// URL repoInfo[1]. It calls b.NewDNFConfIfNeeded() to create the DNF config if it
+// AddRepo adds and enables a repo configuration named <name> pointing at
+// URL <url>. It calls b.NewDNFConfIfNeeded() to create the DNF config if it
 // does not exist and performs a check to see if the repo passed has already
 // been configured.
-func (b *Builder) AddRepo(repoInfo []string) error {
+func (b *Builder) AddRepo(name, url string) error {
 	repo := dnfRepoConf{
-		RepoName: repoInfo[0],
-		RepoURL:  repoInfo[1],
+		RepoName: name,
+		RepoURL:  url,
 	}
 
 	if err := b.NewDNFConfIfNeeded(); err != nil {
@@ -1708,6 +1708,33 @@ func (b *Builder) AddRepo(repoInfo []string) error {
 	return nil
 }
 
+// SetURLRepo sets the URL for the repo <name> to <url>. If <name> does not exist it is
+// created.
+func (b *Builder) SetURLRepo(name, url string) error {
+	if err := b.NewDNFConfIfNeeded(); err != nil {
+		return err
+	}
+
+	DNFConf, err := ini.Load(b.Config.Builder.DNFConf)
+	if err != nil {
+		return err
+	}
+
+	s, err := DNFConf.GetSection(name)
+	if err != nil {
+		// the section doesn't exist, just add a new one
+		return b.AddRepo(name, url)
+	}
+
+	k, err := s.GetKey("baseurl")
+	if err != nil {
+		return err
+	}
+
+	k.SetValue(url)
+	return DNFConf.SaveTo(b.Config.Builder.DNFConf)
+}
+
 // RemoveRepo removes a configured repo <name> if it exists in the DNF configuration.
 // This will fail if a DNF conf has not yet been generated.
 func (b *Builder) RemoveRepo(name string) error {

mixer/cmd/repos.go

@@ -57,11 +57,19 @@ var initRepoCmd = &cobra.Command{
 	Run:   runInitRepo,
 }
 
+var setURLRepoCmd = &cobra.Command{
+	Use:   "set-url <name> <url>",
+	Short: "Sets the URL for repo <name> to <url>",
+	Long:  `Sets the URL, for repo <name> to <url>. If <name> does not exist the repo will be added to the configuration.`,
+	Run:   runSetURLRepo,
+}
+
 var repoCmds = []*cobra.Command{
 	addRepoCmd,
 	removeRepoCmd,
 	listReposCmd,
 	initRepoCmd,
+	setURLRepoCmd,
 }
 
 func init() {
@@ -82,7 +90,7 @@ func runAddRepo(cmd *cobra.Command, args []string) {
 		fail(err)
 	}
 
-	err = b.AddRepo(args)
+	err = b.AddRepo(args[0], args[1])
 	if err != nil {
 		fail(err)
 	}
@@ -128,3 +136,20 @@ func runInitRepo(cmd *cobra.Command, args []string) {
 		fail(err)
 	}
 }
+
+func runSetURLRepo(cmd *cobra.Command, args []string) {
+	if len(args) != 2 {
+		fail(errors.New("set-url requires two arguments: <name> <url>"))
+	}
+
+	b, err := builder.NewFromConfig(config)
+	if err != nil {
+		fail(err)
+	}
+
+	err = b.SetURLRepo(args[0], args[1])
+	if err != nil {
+		fail(err)
+	}
+	fmt.Printf("Set %s baseurl to %s.\n", args[0], args[1])
+}