[direnv] .envrc simplified (#974)

## Summary

Updated .envrc template to make it simpler and also future proof. So
that if the contents of `use devbox` function changes in the future, we
won't have mismatch between devbox binary and user's `.envrc` file.

Added `--envrc` flag to `devbox generate direnv` so that it outputs the
content of `use devbox` function.
Without the flag, the command generates the following:
```
# Automatically sets up your devbox environment whenever you cd into this
# directory via our direnv integration:

eval $(devbox generate direnv --envrc)

Note: this needs a follow up PR for updating the docs in regards to direnv integration.

# check out https://www.jetpack.io/devbox/docs/ide_configuration/direnv/
# for more details
```

## How was it tested?
- compile
- in a new directory run `devbox generate direnv` (answer No to the
prompt)
- update the .envrc file and change `devbox generate ...` to `./devbox
generate` (so that it uses the compiled binary).
- cd out of directory and back in to check if direnv works as expected.

Author: mohsenari

devbox.go

@@ -27,11 +27,12 @@ type Devbox interface {
 	Generate() error
 	GenerateDevcontainer(force bool) error
 	GenerateDockerfile(force bool) error
-	GenerateEnvrc(force bool, source string) error
+	GenerateEnvrcFile(force bool) error
 	Info(pkg string, markdown bool) error
 	ListScripts() []string
 	PrintEnv(ctx context.Context, includeHooks bool) (string, error)
 	PrintGlobalList() error
+	PrintEnvrcContent(w io.Writer) error
 	PullGlobal(path string) error
 	// Remove removes Nix packages from the config so that it no longer exists in
 	// the devbox environment.

internal/boxcli/generate.go

@@ -4,8 +4,6 @@
 package boxcli
 
 import (
-	"os"
-
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 
@@ -14,9 +12,10 @@ import (
 )
 
 type generateCmdFlags struct {
-	config         configFlags
-	force          bool
-	githubUsername string
+	config            configFlags
+	force             bool
+	printEnvrcContent bool
+	githubUsername    string
 }
 
 func generateCmd() *cobra.Command {
@@ -98,6 +97,11 @@ func direnvCmd() *cobra.Command {
 	}
 	command.Flags().BoolVarP(
 		&flags.force, "force", "f", false, "force overwrite existing files")
+	command.Flags().BoolVarP(
+		&flags.printEnvrcContent, "print-envrc", "p", false, "output contents of devbox configuration to use in .envrc")
+	// this command marks a flag as hidden. Error handling for it is not necessary.
+	_ = command.Flags().MarkHidden("print-envrc")
+
 	flags.config.register(command)
 	return command
 }
@@ -125,7 +129,7 @@ func sshConfigCmd() *cobra.Command {
 
 func runGenerateCmd(cmd *cobra.Command, flags *generateCmdFlags) error {
 	// Check the directory exists.
-	box, err := devbox.Open(flags.config.path, os.Stdout)
+	box, err := devbox.Open(flags.config.path, cmd.ErrOrStderr())
 	if err != nil {
 		return errors.WithStack(err)
 	}
@@ -137,7 +141,10 @@ func runGenerateCmd(cmd *cobra.Command, flags *generateCmdFlags) error {
 	case "dockerfile":
 		return box.GenerateDockerfile(flags.force)
 	case "direnv":
-		return box.GenerateEnvrc(flags.force, "generate")
+		if flags.printEnvrcContent {
+			return box.PrintEnvrcContent(cmd.OutOrStdout())
+		}
+		return box.GenerateEnvrcFile(flags.force)
 	}
 	return nil
 }

internal/boxcli/init.go

@@ -32,10 +32,6 @@ func runInitCmd(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return errors.WithStack(err)
 	}
-	box, err := devbox.Open(path, cmd.ErrOrStderr())
-	if err != nil {
-		return errors.WithStack(err)
-	}
 
-	return errors.WithStack(box.GenerateEnvrc(false, "init"))
+	return nil
 }

internal/impl/devbox.go

@@ -15,10 +15,9 @@ import (
 	"runtime/trace"
 	"strings"
 	"text/tabwriter"
+	"text/template"
 
-	"github.com/AlecAivazis/survey/v2"
 	"github.com/fatih/color"
-	"github.com/mattn/go-isatty"
 	"github.com/pkg/errors"
 	"github.com/samber/lo"
 	"golang.org/x/exp/slices"
@@ -42,6 +41,7 @@ import (
 	"go.jetpack.io/devbox/internal/searcher"
 	"go.jetpack.io/devbox/internal/services"
 	"go.jetpack.io/devbox/internal/telemetry"
+	"go.jetpack.io/devbox/internal/ux"
 	"go.jetpack.io/devbox/internal/wrapnix"
 )
 
@@ -388,8 +388,15 @@ func (d *Devbox) GenerateDockerfile(force bool) error {
 	return errors.WithStack(generate.CreateDockerfile(tmplFS, d.projectDir))
 }
 
-// GenerateEnvrc generates a .envrc file that makes direnv integration convenient
-func (d *Devbox) GenerateEnvrc(force bool, source string) error {
+func (d *Devbox) PrintEnvrcContent(w io.Writer) error {
+	tmplName := "envrcContent.tmpl"
+	t := template.Must(template.ParseFS(tmplFS, "tmpl/"+tmplName))
+	// write content into file
+	return t.Execute(w, nil)
+}
+
+// GenerateEnvrcFile generates a .envrc file that makes direnv integration convenient
+func (d *Devbox) GenerateEnvrcFile(force bool) error {
 	ctx, task := trace.NewTask(context.Background(), "devboxGenerateEnvrc")
 	defer task.End()
 
@@ -402,48 +409,31 @@ func (d *Devbox) GenerateEnvrc(force bool, source string) error {
 		)
 	}
 	// confirm .envrc doesn't exist and don't overwrite an existing .envrc
-	if cmdutil.Exists("direnv") {
-		// prompt for direnv allow
-		var result string
-		isInteractiveMode := isatty.IsTerminal(os.Stdin.Fd())
-		if isInteractiveMode {
-			prompt := &survey.Input{
-				Message: "Do you want to enable direnv integration for this devbox project? [y/N]",
-			}
-			err := survey.AskOne(prompt, &result)
-			if err != nil {
-				return errors.WithStack(err)
-			}
-		}
-
-		if strings.ToLower(result) == "y" || !isInteractiveMode || source == "generate" {
-			if err := nix.EnsureNixInstalled(
-				d.writer, func() *bool { return lo.ToPtr(false) },
-			); err != nil {
-				return err
-			}
-
-			// generate all shell files to ensure we can refer to them in the .envrc script
-			if err := d.ensurePackagesAreInstalled(ctx, ensure); err != nil {
-				return err
-			}
+	if err := nix.EnsureNixInstalled(
+		d.writer, func() *bool { return lo.ToPtr(false) },
+	); err != nil {
+		return err
+	}
 
-			// .envrc file creation
-			err := generate.CreateEnvrc(tmplFS, d.projectDir)
-			if err != nil {
-				return errors.WithStack(err)
-			}
-		}
+	// generate all shell files to ensure we can refer to them in the .envrc script
+	if err := d.ensurePackagesAreInstalled(ctx, ensure); err != nil {
+		return err
+	}
 
-		if strings.ToLower(result) == "y" || !isInteractiveMode {
-			cmd := exec.Command("direnv", "allow")
-			err := cmd.Run()
-			if err != nil {
-				return errors.WithStack(err)
-			}
+	// .envrc file creation
+	err := generate.CreateEnvrc(tmplFS, d.projectDir)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	ux.Fsuccess(d.writer, "generated .envrc file\n")
+	if cmdutil.Exists("direnv") {
+		cmd := exec.Command("direnv", "allow")
+		err := cmd.Run()
+		if err != nil {
+			return errors.WithStack(err)
 		}
+		ux.Fsuccess(d.writer, "ran `direnv allow`\n")
 	}
-
 	return nil
 }
 

internal/impl/tmpl/envrc.tmpl

@@ -1,15 +1,7 @@
 # Automatically sets up your devbox environment whenever you cd into this
 # directory via our direnv integration:
 
-use_devbox() {
-    watch_file devbox.json
-    if [ -f .devbox/gen/flake/flake.nix ]; then
-        DEVBOX_SHELL_ENABLED_BACKUP=$DEVBOX_SHELL_ENABLED
-        eval "$(devbox shellenv --init-hook)"
-        export DEVBOX_SHELL_ENABLED=$DEVBOX_SHELL_ENABLED_BACKUP
-    fi
-}
-use devbox
+eval "$(devbox generate direnv --print-envrc)"
 
 # check out https://www.jetpack.io/devbox/docs/ide_configuration/direnv/
 # for more details

internal/impl/tmpl/envrcContent.tmpl

@@ -0,0 +1,5 @@
+use_devbox() {
+    watch_file devbox.json
+    eval "$(devbox shellenv --init-hook)"
+}
+use devbox

internal/ux/messages.go

@@ -10,6 +10,11 @@ import (
 	"github.com/fatih/color"
 )
 
+func Fsuccess(w io.Writer, format string, a ...any) {
+	color.New(color.FgHiGreen).Fprint(w, "Success: ")
+	fmt.Fprintf(w, format, a...)
+}
+
 func Fwarning(w io.Writer, format string, a ...any) {
 	color.New(color.FgHiYellow).Fprint(w, "Warning: ")
 	fmt.Fprintf(w, format, a...)

testscripts/generate/direnv.test.txt

@@ -0,0 +1,4 @@
+exec devbox init
+exec devbox generate direnv
+exists .envrc
+