Merge pull request #245 from roots/new-command-improve-venv-failure

Improve init and virtual error messages

Author: swalkinshaw

cmd/init.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"os"
 	"os/exec"
 	"strings"
 
@@ -58,8 +57,9 @@ func (c *InitCommand) Run(args []string) int {
 	}
 
 	c.UI.Info("Initializing project\n")
+	ok, virtualenvCmd := c.Trellis.Virtualenv.Installed()
 
-	if ok, _ := c.Trellis.Virtualenv.Installed(); !ok {
+	if !ok {
 		c.UI.Info("virtualenv not found")
 		spinner := NewSpinner(
 			SpinnerCfg{
@@ -68,8 +68,20 @@ func (c *InitCommand) Run(args []string) int {
 			},
 		)
 		spinner.Start()
-		c.Trellis.Virtualenv.Install()
+		_, err := c.Trellis.Virtualenv.Install()
 		spinner.Stop()
+
+		c.UI.Error(err.Error())
+		c.UI.Error("")
+		c.UI.Error("Project initialization failed due to the error above.")
+		c.UI.Error("")
+		c.UI.Error("trellis-cli attempted to install virtualenv as a fallback but failed.")
+		c.UI.Error("Without virtualenv, a Python virtual environment cannot be created and the required dependencies (eg: Ansible) can't be installed either.")
+		c.UI.Error("")
+		c.UI.Error("There are two options:")
+		c.UI.Error("  1. Ensure Python 3 is installed and the `python3` command works. trellis-cli will use python3's built-in venv feature.")
+		c.UI.Error(fmt.Sprintf("  2. Disable trellis-cli's virtual env feature by setting this env variable: export %s=false", trellis.TrellisVenvEnvName))
+		return 1
 	}
 
 	if c.force {
@@ -80,7 +92,7 @@ func (c *InitCommand) Run(args []string) int {
 			},
 		)
 		spinner.Start()
-		err := os.RemoveAll(c.Trellis.Virtualenv.Path)
+		err := c.Trellis.Virtualenv.Delete()
 
 		if err != nil {
 			spinner.StopFail()
@@ -105,6 +117,19 @@ func (c *InitCommand) Run(args []string) int {
 		if err != nil {
 			spinner.StopFail()
 			c.UI.Error(err.Error())
+			c.UI.Error("")
+			c.UI.Error("Project initialization failed due to the error above.")
+			c.UI.Error("")
+			c.UI.Error("trellis-cli tried to create a virtual environment but failed.")
+			c.UI.Error(fmt.Sprintf("  => %s", virtualenvCmd.String()))
+			c.UI.Error("")
+			c.UI.Error("Without a Python virtual environment the required dependencies (eg: Ansible) can't be installed.")
+			c.UI.Error("")
+			c.UI.Error("There are two options:")
+			c.UI.Error("  1. Ensure Python 3 is installed and the `python3` command works. trellis-cli will use python3's built-in venv feature.")
+			c.UI.Error(fmt.Sprintf("  2. Disable trellis-cli's virtual env feature by setting this env variable: export %s=false", trellis.TrellisVenvEnvName))
+			c.UI.Error("")
+			c.UI.Error("This could also be a bug in trellis-cli. Please create an issue at https://github.com/roots/trellis-cli and include the output above.")
 			return 1
 		}
 

cmd/new.go

@@ -122,7 +122,11 @@ func (c *NewCommand) Run(args []string) int {
 
 	if !c.skipVirtualenv {
 		initCommand := NewInitCommand(c.UI, c.trellis)
-		initCommand.Run([]string{})
+		code := initCommand.Run([]string{})
+
+		if code != 0 {
+			return 1
+		}
 	}
 
 	// Update default configs

trellis/virtualenv.go

@@ -69,6 +69,10 @@ func (v *Virtualenv) Deactivate() {
 	os.Setenv(PathEnvName, v.OldPath)
 }
 
+func (v *Virtualenv) Delete() error {
+	return os.RemoveAll(v.Path)
+}
+
 func (v *Virtualenv) LocalPath() string {
 	configHome := os.Getenv("XDG_CONFIG_HOME")
 
@@ -96,17 +100,17 @@ func (v *Virtualenv) Initialized() bool {
 	return true
 }
 
-func (v *Virtualenv) Install() string {
+func (v *Virtualenv) Install() (installPath string, err error) {
 	localPath := v.LocalPath()
 	configDir := filepath.Dir(localPath)
 
-	if _, err := os.Stat(configDir); os.IsNotExist(err) {
+	if _, err = os.Stat(configDir); os.IsNotExist(err) {
 		if err = os.MkdirAll(configDir, 0755); err != nil {
-			log.Fatal(err)
+			return "", err
 		}
 	}
 
-	return github.DownloadRelease("pypa/virtualenv", "latest", os.TempDir(), localPath)
+	return github.DownloadRelease("pypa/virtualenv", "latest", os.TempDir(), localPath), nil
 }
 
 func (v *Virtualenv) Installed() (ok bool, cmd *exec.Cmd) {