feat: Add template pull cmd (#2329)

cli/templatepull.go

@@ -0,0 +1,123 @@
+package cli
+
+import (
+	"fmt"
+	"io/fs"
+	"os"
+	"sort"
+
+	"github.com/spf13/cobra"
+	"golang.org/x/xerrors"
+
+	"github.com/coder/coder/cli/cliui"
+	"github.com/coder/coder/codersdk"
+)
+
+func templatePull() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "pull <name> [destination]",
+		Short: "Download the latest version of a template to a path.",
+		Args:  cobra.MaximumNArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			var (
+				ctx          = cmd.Context()
+				templateName = args[0]
+				dest         string
+			)
+
+			if len(args) > 1 {
+				dest = args[1]
+			}
+
+			client, err := createClient(cmd)
+			if err != nil {
+				return xerrors.Errorf("create client: %w", err)
+			}
+
+			// TODO(JonA): Do we need to add a flag for organization?
+			organization, err := currentOrganization(cmd, client)
+			if err != nil {
+				return xerrors.Errorf("current organization: %w", err)
+			}
+
+			template, err := client.TemplateByName(ctx, organization.ID, templateName)
+			if err != nil {
+				return xerrors.Errorf("template by name: %w", err)
+			}
+
+			// Pull the versions for the template. We'll find the latest
+			// one and download the source.
+			versions, err := client.TemplateVersionsByTemplate(ctx, codersdk.TemplateVersionsByTemplateRequest{
+				TemplateID: template.ID,
+			})
+			if err != nil {
+				return xerrors.Errorf("template versions by template: %w", err)
+			}
+
+			if len(versions) == 0 {
+				return xerrors.Errorf("no template versions for template %q", templateName)
+			}
+
+			// Sort the slice from newest to oldest template.
+			sort.SliceStable(versions, func(i, j int) bool {
+				return versions[i].CreatedAt.After(versions[j].CreatedAt)
+			})
+
+			latest := versions[0]
+
+			// Download the tar archive.
+			raw, ctype, err := client.Download(ctx, latest.Job.StorageSource)
+			if err != nil {
+				return xerrors.Errorf("download template: %w", err)
+			}
+
+			if ctype != codersdk.ContentTypeTar {
+				return xerrors.Errorf("unexpected Content-Type %q, expecting %q", ctype, codersdk.ContentTypeTar)
+			}
+
+			// If the destination is empty then we write to stdout
+			// and bail early.
+			if dest == "" {
+				_, err = cmd.OutOrStdout().Write(raw)
+				if err != nil {
+					return xerrors.Errorf("write stdout: %w", err)
+				}
+				return nil
+			}
+
+			// Stat the destination to ensure nothing exists already.
+			fi, err := os.Stat(dest)
+			if err != nil && !xerrors.Is(err, fs.ErrNotExist) {
+				return xerrors.Errorf("stat destination: %w", err)
+			}
+
+			if fi != nil && fi.IsDir() {
+				// If the destination is a directory we just bail.
+				return xerrors.Errorf("%q already exists.", dest)
+			}
+
+			// If a file exists at the destination prompt the user
+			// to ensure we don't overwrite something valuable.
+			if fi != nil {
+				_, err = cliui.Prompt(cmd, cliui.PromptOptions{
+					Text:      fmt.Sprintf("%q already exists, do you want to overwrite it?", dest),
+					IsConfirm: true,
+				})
+				if err != nil {
+					return xerrors.Errorf("parse prompt: %w", err)
+				}
+			}
+
+			err = os.WriteFile(dest, raw, 0600)
+			if err != nil {
+				return xerrors.Errorf("write to path: %w", err)
+			}
+
+			return nil
+		},
+	}
+
+	cliui.AllowSkipPrompt(cmd)
+
+	return cmd
+}