feat(tool/charts): add repo cmd (#455)

* feat(tool/charts): add repo cmd

Adds tk tool charts add-repo for adding a repository using the CLI

* doc: add-repo cmd

* feat(tool/charts): make add-repo idempotent

cmd/tk/toolCharts.go

@@ -20,6 +20,7 @@ func chartsCmd() *cli.Command {
 	cmd.AddCommand(
 		chartsInitCmd(),
 		chartsAddCmd(),
+		chartsAddRepoCmd(),
 		chartsVendorCmd(),
 		chartsConfigCmd(),
 	)
@@ -63,6 +64,28 @@ func chartsAddCmd() *cli.Command {
 	return cmd
 }
 
+func chartsAddRepoCmd() *cli.Command {
+	cmd := &cli.Command{
+		Use:   "add-repo [NAME] [URL]",
+		Short: "Adds a repository to the chartfile",
+		Args:  cli.ArgsExact(2),
+	}
+
+	cmd.Run = func(cmd *cli.Command, args []string) error {
+		c, err := loadChartfile()
+		if err != nil {
+			return err
+		}
+
+		return c.AddRepos(helm.Repo{
+			Name: args[0],
+			URL:  args[1],
+		})
+	}
+
+	return cmd
+}
+
 func chartsConfigCmd() *cli.Command {
 	cmd := &cli.Command{
 		Use:   "config",

docs/docs/helm.mdx

@@ -18,7 +18,8 @@ resource definition, you can still consume Helm resources, as described below.
 
 Helm support is provided using the
 [`github.com/grafana/jsonnet-libs/tanka-util`](https://github.com/grafana/jsonnet-libs/tree/master/tanka-util)
-library.  Install it with:
+library. Install it with:
+
 ```bash
 jb install github.com/grafana/jsonnet-libs/tanka-util
 ```
@@ -136,8 +137,14 @@ This will also call `tk tool charts vendor`, so that the `charts/` directory is
 
 **Adding Repositories:**
 By default, the `stable` repository is automatically set up for you. If you wish
-to add another repository, you currently need modify `chartfile.yaml` directly
-to add it:
+to add another repository, you can use the `add-repo` command:
+
+```bash
+# Add the official Grafana repository
+$ tk tool charts add-repo grafana https://grafana.github.io/helm-charts
+```
+
+Another way is to modify `chartfile.yaml` directly:
 
 ```diff
 version: 1

pkg/helm/charts.go

@@ -142,7 +142,7 @@ func (c Charts) Vendor() error {
 
 // Add adds every Chart in reqs to the Manifest after validation, and runs
 // Vendor afterwards
-func (c Charts) Add(reqs []string) error {
+func (c *Charts) Add(reqs []string) error {
 	log.Printf("Adding %v Charts ...", len(reqs))
 
 	skip := func(s string, err error) {
@@ -183,6 +183,29 @@ func (c Charts) Add(reqs []string) error {
 	return c.Vendor()
 }
 
+func (c *Charts) AddRepos(repos ...Repo) error {
+	added := 0
+	for _, r := range repos {
+		if c.Manifest.Repositories.Has(r) {
+			log.Printf("Skipping %s: Already exists", r.Name)
+			continue
+		}
+
+		c.Manifest.Repositories = append(c.Manifest.Repositories, r)
+	}
+
+	// write out
+	if err := write(c.Manifest, c.ManifestFile()); err != nil {
+		return err
+	}
+
+	if added != len(repos) {
+		return fmt.Errorf("%v Chart(s) were skipped. Please check above logs for details", len(repos)-added)
+	}
+
+	return nil
+}
+
 func InitChartfile(path string) (*Charts, error) {
 	c := Chartfile{
 		Version: Version,

pkg/helm/spec.go

@@ -23,7 +23,7 @@ type Chartfile struct {
 	Version uint `json:"version"`
 
 	// Repositories to source from
-	Repositories []Repo `json:"repositories"`
+	Repositories Repos `json:"repositories"`
 
 	// Requires lists Charts expected to be present in the charts folder
 	Requires Requirements `json:"requires"`
@@ -43,6 +43,19 @@ type Repo struct {
 	Password string `json:"password,omitempty"`
 }
 
+type Repos []Repo
+
+// Has reports whether 'repo' is already part of the repositories
+func (r Repos) Has(repo Repo) bool {
+	for _, x := range r {
+		if x == repo {
+			return true
+		}
+	}
+
+	return false
+}
+
 // Requirement describes a single required Helm Chart.
 // Both, Chart and Version are required
 type Requirement struct {