Enable lazy create of repo file for repo commannds

Adding Lazy create of repository file for `helm repo` commands
in addition to `repo update`.

Signed-off-by: Martin Hickey <martin.hickey@ie.ibm.com>

cmd/helm/repo_add_test.go

@@ -67,7 +67,7 @@ func TestRepoAdd(t *testing.T) {
 		t.Error(err)
 	}
 
-	f, err := repo.LoadFile(repoFile)
+	f, err := repo.LoadFile(repoFile, false)
 	if err != nil {
 		t.Fatal(err)
 	}

cmd/helm/repo_list.go

@@ -34,7 +34,7 @@ func newRepoListCmd(out io.Writer) *cobra.Command {
 		Short: "list chart repositories",
 		Args:  require.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			f, err := repo.LoadFile(settings.RepositoryConfig)
+			f, err := repo.LoadFile(settings.RepositoryConfig, true)
 			if err != nil {
 				return err
 			}

cmd/helm/repo_remove.go

@@ -55,7 +55,7 @@ func newRepoRemoveCmd(out io.Writer) *cobra.Command {
 }
 
 func (o *repoRemoveOptions) run(out io.Writer) error {
-	r, err := repo.LoadFile(o.repoFile)
+	r, err := repo.LoadFile(o.repoFile, true)
 	if err != nil {
 		return err
 	}

cmd/helm/repo_remove_test.go

@@ -80,7 +80,7 @@ func TestRepoRemove(t *testing.T) {
 		t.Errorf("Error cache file was not removed for repository %s", testRepoName)
 	}
 
-	f, err := repo.LoadFile(repoFile)
+	f, err := repo.LoadFile(repoFile, false)
 	if err != nil {
 		t.Error(err)
 	}

cmd/helm/repo_update.go

@@ -59,7 +59,7 @@ func newRepoUpdateCmd(out io.Writer) *cobra.Command {
 }
 
 func (o *repoUpdateOptions) run(out io.Writer) error {
-	f, err := repo.LoadFile(o.repoFile)
+	f, err := repo.LoadFile(o.repoFile, true)
 	if err != nil {
 		return err
 	}

cmd/helm/search_repo.go

@@ -146,7 +146,7 @@ func (o *searchRepoOptions) formatSearchResults(res []*search.Result) string {
 
 func (o *searchRepoOptions) buildIndex(out io.Writer) (*search.Index, error) {
 	// Load the repositories.yaml
-	rf, err := repo.LoadFile(o.repoFile)
+	rf, err := repo.LoadFile(o.repoFile, true)
 	if err != nil {
 		return nil, errors.Wrap(err, "loading repository config")
 	}

pkg/downloader/chart_downloader.go

@@ -154,7 +154,7 @@ func (c *ChartDownloader) ResolveChartVersion(ref, version string) (*url.URL, er
 	}
 	c.Options = append(c.Options, getter.WithURL(ref))
 
-	rf, err := repo.LoadFile(c.RepositoryConfig)
+	rf, err := repo.LoadFile(c.RepositoryConfig, false)
 	if err != nil {
 		return u, err
 	}

pkg/downloader/chart_downloader_test.go

@@ -222,7 +222,7 @@ func TestScanReposForURL(t *testing.T) {
 	}
 
 	u := "http://example.com/alpine-0.2.0.tgz"
-	rf, err := repo.LoadFile(repoConfig)
+	rf, err := repo.LoadFile(repoConfig, false)
 	if err != nil {
 		t.Fatal(err)
 	}

pkg/downloader/manager.go

@@ -311,7 +311,7 @@ func (m *Manager) safeDeleteDep(name, dir string) error {
 
 // hasAllRepos ensures that all of the referenced deps are in the local repo cache.
 func (m *Manager) hasAllRepos(deps []*chart.Dependency) error {
-	rf, err := repo.LoadFile(m.RepositoryConfig)
+	rf, err := repo.LoadFile(m.RepositoryConfig, false)
 	if err != nil {
 		return err
 	}
@@ -345,7 +345,7 @@ Loop:
 
 // getRepoNames returns the repo names of the referenced deps which can be used to fetch the cahced index file.
 func (m *Manager) getRepoNames(deps []*chart.Dependency) (map[string]string, error) {
-	rf, err := repo.LoadFile(m.RepositoryConfig)
+	rf, err := repo.LoadFile(m.RepositoryConfig, false)
 	if err != nil {
 		if os.IsNotExist(err) {
 			return make(map[string]string), nil
@@ -415,7 +415,7 @@ repository, use "https://charts.example.com/" or "@example" instead of
 
 // UpdateRepositories updates all of the local repos to the latest.
 func (m *Manager) UpdateRepositories() error {
-	rf, err := repo.LoadFile(m.RepositoryConfig)
+	rf, err := repo.LoadFile(m.RepositoryConfig, false)
 	if err != nil {
 		return err
 	}
@@ -553,7 +553,7 @@ func (m *Manager) loadChartRepositories() (map[string]*repo.ChartRepository, err
 	indices := map[string]*repo.ChartRepository{}
 
 	// Load repositories.yaml file
-	rf, err := repo.LoadFile(m.RepositoryConfig)
+	rf, err := repo.LoadFile(m.RepositoryConfig, false)
 	if err != nil {
 		return indices, errors.Wrapf(err, "failed to load %s", m.RepositoryConfig)
 	}

pkg/repo/repo.go

@@ -45,9 +45,19 @@ func NewFile() *File {
 }
 
 // LoadFile takes a file at the given path and returns a File object
-func LoadFile(path string) (*File, error) {
+// createRepoFile parameter when set to true, will create repo file if
+// it doesn't exist. The parameter is useful for lazy create when
+// running some commands.
+func LoadFile(path string, createRepoFile bool) (*File, error) {
 	b, err := ioutil.ReadFile(path)
 	if err != nil {
+		if os.IsNotExist(err) && createRepoFile {
+			f := &File{}
+			if err := f.WriteFile(path, 0644); err != nil {
+				return nil, errors.Wrapf(err, "couldn't load repositories file (%s)", path)
+			}
+			return f, nil
+		}
 		if os.IsNotExist(err) {
 			return nil, errors.Wrapf(err, "couldn't load repositories file (%s)", path)
 		}

pkg/repo/repo_test.go

@@ -71,7 +71,7 @@ func TestNewFile(t *testing.T) {
 		},
 	)
 
-	file, err := LoadFile(testRepositoriesFile)
+	file, err := LoadFile(testRepositoriesFile, false)
 	if err != nil {
 		t.Errorf("%q could not be loaded: %s", testRepositoriesFile, err)
 	}
@@ -169,7 +169,7 @@ func TestWriteFile(t *testing.T) {
 		t.Errorf("failed to write file (%v)", err)
 	}
 
-	repos, err := LoadFile(file.Name())
+	repos, err := LoadFile(file.Name(), false)
 	if err != nil {
 		t.Errorf("failed to load file (%v)", err)
 	}
@@ -181,9 +181,21 @@ func TestWriteFile(t *testing.T) {
 }
 
 func TestRepoNotExists(t *testing.T) {
-	if _, err := LoadFile("/this/path/does/not/exist.yaml"); err == nil {
+	if _, err := LoadFile("/this/path/does/not/exist.yaml", false); err == nil {
 		t.Errorf("expected err to be non-nil when path does not exist")
 	} else if !strings.Contains(err.Error(), "couldn't load repositories file") {
 		t.Errorf("expected prompt `couldn't load repositories file`")
 	}
 }
+
+func TestRepoLazyCreate(t *testing.T) {
+	f, err := LoadFile("testdata/helm-repo-lazy-tst.yaml", true)
+	if err != nil {
+		t.Errorf("expected err to be nil when path does not exist and create repo file flag set")
+	}
+	if len(f.Repositories) != 0 {
+		os.Remove("testdata/helm-repo-lazy-tst.yaml")
+		t.Errorf("expected no rep[ositories to be returned")
+	}
+	os.Remove("testdata/helm-repo-lazy-tst.yaml")
+}