command: use new diagnostics output for config errors

This uses the new diagnostics printer for config-related errors in the
main five commands that deal with config.

The immediate motivation for this is to allow HCL2-produced diagnostics
to be printed out in their full fidelity, though it also slightly changes
the presentation of other errors so that they are not presented in all
red text, which can be hard to read on some terminals.

command/apply.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/go-getter"
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/config"
@@ -130,7 +131,8 @@ func (c *ApplyCommand) Run(args []string) int {
 	if plan == nil {
 		mod, err = c.Module(configPath)
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf("Failed to load root config module: %s", err))
+			err = errwrap.Wrapf("Failed to load root config module: {{err}}", err)
+			c.showDiagnostics(err)
 			return 1
 		}
 	}

command/init.go

@@ -155,8 +155,10 @@ func (c *InitCommand) Run(args []string) int {
 	if flagGet || flagBackend {
 		conf, err := c.Config(path)
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf(
-				"Error loading configuration: %s", err))
+			// Since this may be the user's first ever interaction with Terraform,
+			// we'll provide some additional context in this case.
+			c.Ui.Error(strings.TrimSpace(errInitConfigError))
+			c.showDiagnostics(err)
 			return 1
 		}
 
@@ -551,6 +553,13 @@ func (c *InitCommand) Synopsis() string {
 	return "Initialize a Terraform working directory"
 }
 
+const errInitConfigError = `
+There are some problems with the configuration, described below.
+
+The Terraform configuration must be valid before initialization so that
+Terraform can determine which modules and providers need to be installed.
+`
+
 const errInitCopyNotEmpty = `
 The working directory already contains files. The -from-module option requires
 an empty directory into which a copy of the referenced module will be placed.

command/plan.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/config/module"
@@ -73,7 +74,8 @@ func (c *PlanCommand) Run(args []string) int {
 	if plan == nil {
 		mod, err = c.Module(configPath)
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf("Failed to load root config module: %s", err))
+			err = errwrap.Wrapf("Failed to load root config module: {{err}}", err)
+			c.showDiagnostics(err)
 			return 1
 		}
 	}

command/refresh.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/hashicorp/errwrap"
 	"github.com/hashicorp/terraform/backend"
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/terraform"
@@ -43,7 +44,8 @@ func (c *RefreshCommand) Run(args []string) int {
 	// Load the module
 	mod, err := c.Module(configPath)
 	if err != nil {
-		c.Ui.Error(fmt.Sprintf("Failed to load root config module: %s", err))
+		err = errwrap.Wrapf("Failed to load root config module: {{err}}", err)
+		c.showDiagnostics(err)
 		return 1
 	}
 

command/validate.go

@@ -91,21 +91,19 @@ Options:
 func (c *ValidateCommand) validate(dir string, checkVars bool) int {
 	cfg, err := config.LoadDir(dir)
 	if err != nil {
-		c.Ui.Error(fmt.Sprintf(
-			"Error loading files %v\n", err.Error()))
+		c.showDiagnostics(err)
 		return 1
 	}
 	err = cfg.Validate()
 	if err != nil {
-		c.Ui.Error(fmt.Sprintf(
-			"Error validating: %v\n", err.Error()))
+		c.showDiagnostics(err)
 		return 1
 	}
 
 	if checkVars {
 		mod, err := c.Module(dir)
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf("Failed to load root config module: %s", err))
+			c.showDiagnostics(err)
 			return 1
 		}
 
@@ -114,7 +112,7 @@ func (c *ValidateCommand) validate(dir string, checkVars bool) int {
 
 		tfCtx, err := terraform.NewContext(opts)
 		if err != nil {
-			c.Ui.Error(fmt.Sprintf("Error: %v\n", err.Error()))
+			c.showDiagnostics(err)
 			return 1
 		}