Add edit command

Signed-off-by: ye.sijun <[email protected]>

Author: junnplus

README.md

@@ -151,6 +151,8 @@ Detailed usage:
 
 - Run `limactl delete [--force] <INSTANCE>` to delete the instance.
 
+- Run `limactl edit <INSTANCE>` to edit the instance.
+
 - To enable bash completion, add `source <(limactl completion bash)` to `~/.bash_profile`.
 
 - To enable zsh completion, see `limactl completion zsh --help`

cmd/limactl/edit.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/lima-vm/lima/pkg/limayaml"
+	"github.com/lima-vm/lima/pkg/store"
+	"github.com/lima-vm/lima/pkg/store/filenames"
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+)
+
+func newEditCommand() *cobra.Command {
+	var editCommand = &cobra.Command{
+		Use:               "edit INSTANCE",
+		Short:             "Edit an instance of Lima",
+		Args:              cobra.MaximumNArgs(1),
+		RunE:              editAction,
+		ValidArgsFunction: editBashComplete,
+	}
+	return editCommand
+}
+
+func editAction(cmd *cobra.Command, args []string) error {
+	instName := DefaultInstanceName
+	if len(args) > 0 {
+		instName = args[0]
+	}
+
+	inst, err := store.Inspect(instName)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			logrus.Infof("Instance %q not found", instName)
+			return nil
+		}
+		return err
+	}
+
+	filePath := filepath.Join(inst.Dir, filenames.LimaYAML)
+	yContent, err := os.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
+	hdr := fmt.Sprintf("# Please edit the folling configuration for Lima instance %q\n", instName)
+	hdr += "# and an empty file will abort the edit.\n"
+	hdr += "\n"
+	yBytes, err := openEditor(cmd, instName, yContent, hdr)
+	if err != nil {
+		return err
+	}
+	if len(yBytes) == 0 {
+		logrus.Info("Aborting, as requested by saving the file with empty content")
+		return nil
+	}
+	if bytes.Compare(yBytes, yContent) == 0 {
+		logrus.Info("Aborting, no changes made to the instance")
+		return nil
+	}
+	y, err := limayaml.Load(yBytes, filePath)
+	if err != nil {
+		return err
+	}
+	if err := limayaml.Validate(*y, true); err != nil {
+		rejectedYAML := "lima.REJECTED.yaml"
+		if writeErr := os.WriteFile(rejectedYAML, yBytes, 0644); writeErr != nil {
+			return fmt.Errorf("the YAML is invalid, attempted to save the buffer as %q but failed: %v: %w", rejectedYAML, writeErr, err)
+		}
+		// TODO: may need to support editing the rejected YAML
+		return fmt.Errorf("the YAML is invalid, saved the buffer as %q: %w", rejectedYAML, err)
+	}
+	if err := os.WriteFile(filePath, yBytes, 0644); err != nil {
+		return err
+	}
+	logrus.Infof("Instance %q edited, you need restart instance to apply it", instName)
+	return nil
+}
+
+func editBashComplete(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	return bashCompleteInstanceNames(cmd)
+}

cmd/limactl/main.go

@@ -82,6 +82,7 @@ func newApp() *cobra.Command {
 		newInfoCommand(),
 		newShowSSHCommand(),
 		newDebugCommand(),
+		newEditCommand(),
 	)
 	return rootCmd
 }

cmd/limactl/start.go

@@ -141,7 +141,13 @@ func loadOrCreateInstance(cmd *cobra.Command, args []string) (*store.Instance, e
 			answerOpenEditor = false
 		}
 		if answerOpenEditor {
-			yBytes, err = openEditor(cmd, instName, yBytes)
+			hdr := fmt.Sprintf("# Review and modify the following configuration for Lima instance %q.\n", instName)
+			if instName == DefaultInstanceName {
+				hdr += "# - In most cases, you do not need to modify this file.\n"
+			}
+			hdr += "# - To cancel starting Lima, just save this file as an empty file.\n"
+			hdr += "\n"
+			yBytes, err = openEditor(cmd, instName, yBytes, hdr)
 			if err != nil {
 				return nil, err
 			}
@@ -208,7 +214,7 @@ func askWhetherToOpenEditor(name string) (bool, error) {
 // openEditor opens an editor, and returns the content (not path) of the modified yaml.
 //
 // openEditor returns nil when the file was saved as an empty file, optionally with whitespaces.
-func openEditor(cmd *cobra.Command, name string, initialContent []byte) ([]byte, error) {
+func openEditor(cmd *cobra.Command, name string, content []byte, hdr string) ([]byte, error) {
 	editor := editorcmd.Detect()
 	if editor == "" {
 		return nil, errors.New("could not detect a text editor binary, try setting $EDITOR")
@@ -219,14 +225,8 @@ func openEditor(cmd *cobra.Command, name string, initialContent []byte) ([]byte,
 	}
 	tmpYAMLPath := tmpYAMLFile.Name()
 	defer os.RemoveAll(tmpYAMLPath)
-	hdr := fmt.Sprintf("# Review and modify the following configuration for Lima instance %q.\n", name)
-	if name == DefaultInstanceName {
-		hdr += "# - In most cases, you do not need to modify this file.\n"
-	}
-	hdr += "# - To cancel starting Lima, just save this file as an empty file.\n"
-	hdr += "\n"
 	if err := os.WriteFile(tmpYAMLPath,
-		append([]byte(hdr), initialContent...),
+		append([]byte(hdr), content...),
 		0o600); err != nil {
 		return nil, err
 	}