boxcli: devbox cache enable (#2157)

Add a `devbox cache enable` subcommand that:

1. Opens a browser and performs the login flow is the user isn't logged
in.
2. Configures Nix to use the Jetify cache if it isn't already.

The login flow redirects to the new cloud.jetify.com/team/cache URL to
let the user know the cache is enabled.

internal/boxcli/auth.go

@@ -38,7 +38,7 @@ func loginCmd() *cobra.Command {
 		Short: "Login to devbox",
 		Args:  cobra.ExactArgs(0),
 		RunE: func(cmd *cobra.Command, args []string) error {
-			c, err := identity.AuthClient()
+			c, err := identity.AuthClient(identity.AuthRedirectDefault)
 			if err != nil {
 				return err
 			}
@@ -62,7 +62,7 @@ func logoutCmd() *cobra.Command {
 		Short: "Logout from devbox",
 		Args:  cobra.ExactArgs(0),
 		RunE: func(cmd *cobra.Command, args []string) error {
-			c, err := identity.AuthClient()
+			c, err := identity.AuthClient(identity.AuthRedirectDefault)
 			if err != nil {
 				return err
 			}

internal/boxcli/cache.go

@@ -15,6 +15,7 @@ import (
 	"github.com/spf13/cobra"
 	"go.jetpack.io/devbox/internal/devbox"
 	"go.jetpack.io/devbox/internal/devbox/devopt"
+	"go.jetpack.io/devbox/internal/devbox/providers/identity"
 	"go.jetpack.io/devbox/internal/devbox/providers/nixcache"
 	nixv1alpha1 "go.jetpack.io/pkg/api/gen/priv/nix/v1alpha1"
 )
@@ -72,6 +73,7 @@ func cacheCmd() *cobra.Command {
 	cacheCommand.AddCommand(uploadCommand)
 	cacheCommand.AddCommand(cacheConfigureCmd())
 	cacheCommand.AddCommand(cacheCredentialsCmd())
+	cacheCommand.AddCommand(cacheEnableCmd())
 	cacheCommand.AddCommand(cacheInfoCmd())
 
 	return cacheCommand
@@ -143,6 +145,49 @@ func cacheCredentialsCmd() *cobra.Command {
 	return cmd
 }
 
+func cacheEnableCmd() *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "enable",
+		Short: "Enable the Devbox Nix cache for your account",
+		Long: heredoc.Doc(`
+			Sign up or log in to a Jetify Cloud account and configure Nix to use the
+			account's Nix cache.
+
+			For more about how Devbox configures Nix, see "devbox cache configure -h".
+		`),
+		Args: cobra.ExactArgs(0),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			auth, err := identity.AuthClient(identity.AuthRedirectCache)
+			if err != nil {
+				return err
+			}
+			sess, _ := auth.GetSessions()
+			needLogin := len(sess) == 0
+			if needLogin {
+				_, err = auth.LoginFlow()
+				if err != nil {
+					return err
+				}
+			}
+
+			needConfigure := !nixcache.IsConfigured(cmd.Context())
+			if needConfigure {
+				u, _ := user.Current()
+				err = nixcache.ConfigureReprompt(cmd.Context(), u.Username)
+				if err != nil {
+					return err
+				}
+			}
+
+			if !needConfigure && !needLogin {
+				fmt.Fprintln(cmd.OutOrStdout(), "The Devbox cache is already enabled for your account.")
+			}
+			return nil
+		},
+	}
+	return cmd
+}
+
 func cacheInfoCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "info",

internal/devbox/providers/identity/identity.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"os"
+	"path"
 
 	"github.com/go-jose/go-jose/v4"
 	"github.com/go-jose/go-jose/v4/jwt"
@@ -16,6 +17,16 @@ import (
 	"golang.org/x/oauth2"
 )
 
+// Common redirect URLs for use with [AuthClient].
+var (
+	// AuthRedirectDefault redirects to a generic success page.
+	AuthRedirectDefault = build.SuccessRedirect()
+
+	// AuthRedirectCache redirects to the "Cache" tab in the dashboard for
+	// the authenticated organization.
+	AuthRedirectCache = path.Join(build.DashboardHostname(), "team", "cache")
+)
+
 var scopes = []string{"openid", "offline_access", "email", "profile"}
 
 var cachedAccessTokenFromAPIToken *session.Token
@@ -25,7 +36,7 @@ func GenSession(ctx context.Context) (*session.Token, error) {
 		return t, err
 	}
 
-	c, err := AuthClient()
+	c, err := AuthClient(AuthRedirectDefault)
 	if err != nil {
 		return nil, err
 	}
@@ -37,7 +48,7 @@ func Peek() (*session.Token, error) {
 		return cachedAccessTokenFromAPIToken, nil
 	}
 
-	c, err := AuthClient()
+	c, err := AuthClient(AuthRedirectDefault)
 	if err != nil {
 		return nil, err
 	}
@@ -53,12 +64,13 @@ func Peek() (*session.Token, error) {
 	return tokens[0].Peek(), nil
 }
 
-func AuthClient() (*auth.Client, error) {
+// AuthClient returns a new client that redirects to a given URL upon success.
+func AuthClient(redirect string) (*auth.Client, error) {
 	return auth.NewClient(
 		build.Issuer(),
 		build.ClientID(),
 		scopes,
-		build.SuccessRedirect(),
+		redirect,
 		build.Audience(),
 	)
 }