Improve the output of the `databricks bundle init` command (#795)

Improve the output of help, prompts, and so on for `databricks bundle
init` and the default template.

Among other things, this PR adds support for a new `welcome_message`
property that lets a template print a custom message on success:

```
$ databricks bundle init
Template to use [default-python]:
Unique name for this project [my_project]: lennart_project
Include a stub (sample) notebook in 'lennart_project/src': yes
Include a stub (sample) Delta Live Tables pipeline in 'lennart_project/src': yes
Include a stub (sample) Python package in 'lennart_project/src': yes

✨ Your new project has been created in the 'lennart_project' directory!

Please refer to the README.md of your project for further instructions on getting started.
Or read the documentation on Databricks Asset Bundles at https://docs.databricks.com/dev-tools/bundles/index.html.
```

---------

Co-authored-by: shreyas-goenka <88374338+shreyas-goenka@users.noreply.github.com>

cmd/bundle/init.go

@@ -45,20 +45,29 @@ func repoName(url string) string {
 func newInitCommand() *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "init [TEMPLATE_PATH]",
-		Short: "Initialize Template",
+		Short: "Initialize using a bundle template",
 		Args:  cobra.MaximumNArgs(1),
+		Long: `Initialize using a bundle template.
+
+TEMPLATE_PATH optionally specifies which template to use. It can be one of the following:
+- 'default-python' for the default Python template
+- a local file system path with a template directory
+- a Git repository URL, e.g. https://github.com/my/repository
+
+See https://docs.databricks.com//dev-tools/bundles/templates.html for more information on templates.`,
 	}
 
 	var configFile string
 	var outputDir string
 	var templateDir string
 	cmd.Flags().StringVar(&configFile, "config-file", "", "File containing input parameters for template initialization.")
-	cmd.Flags().StringVar(&templateDir, "template-dir", "", "Directory within repository that holds the template specification.")
+	cmd.Flags().StringVar(&templateDir, "template-dir", "", "Directory path within a Git repository containing the template.")
 	cmd.Flags().StringVar(&outputDir, "output-dir", "", "Directory to write the initialized template to.")
 
 	cmd.PreRunE = root.MustWorkspaceClient
 	cmd.RunE = func(cmd *cobra.Command, args []string) error {
 		ctx := cmd.Context()
+
 		var templatePath string
 		if len(args) > 0 {
 			templatePath = args[0]
@@ -79,6 +88,9 @@ func newInitCommand() *cobra.Command {
 		}
 
 		if !isRepoUrl(templatePath) {
+			if templateDir != "" {
+				return errors.New("--template-dir can only be used with a Git repository URL")
+			}
 			// skip downloading the repo because input arg is not a URL. We assume
 			// it's a path on the local file system in that case
 			return template.Materialize(ctx, configFile, templatePath, outputDir)

libs/jsonschema/extension.go

@@ -12,6 +12,9 @@ type Extension struct {
 	// that do have an order defined.
 	Order *int `json:"order,omitempty"`
 
+	// The message to print after the template is successfully initalized
+	SuccessMessage string `json:"success_message,omitempty"`
+
 	// PatternMatchFailureMessage is a user defined message that is displayed to the
 	// user if a JSON schema pattern match fails.
 	PatternMatchFailureMessage string `json:"pattern_match_failure_message,omitempty"`

libs/jsonschema/instance.go

@@ -39,14 +39,17 @@ func (s *Schema) LoadInstance(path string) (map[string]any, error) {
 	return instance, s.ValidateInstance(instance)
 }
 
+// Validate an instance against the schema
 func (s *Schema) ValidateInstance(instance map[string]any) error {
-	for _, fn := range []func(map[string]any) error{
+	validations := []func(map[string]any) error{
 		s.validateAdditionalProperties,
 		s.validateEnum,
 		s.validateRequired,
 		s.validateTypes,
 		s.validatePattern,
-	} {
+	}
+
+	for _, fn := range validations {
 		err := fn(instance)
 		if err != nil {
 			return err

libs/template/config.go

@@ -65,7 +65,7 @@ func (c *config) assignValuesFromFile(path string) error {
 }
 
 // Assigns default values from schema to input config map
-func (c *config) assignDefaultValues() error {
+func (c *config) assignDefaultValues(r *renderer) error {
 	for name, property := range c.schema.Properties {
 		// Config already has a value assigned
 		if _, ok := c.values[name]; ok {
@@ -75,13 +75,25 @@ func (c *config) assignDefaultValues() error {
 		if property.Default == nil {
 			continue
 		}
-		c.values[name] = property.Default
+		defaultVal, err := jsonschema.ToString(property.Default, property.Type)
+		if err != nil {
+			return err
+		}
+		defaultVal, err = r.executeTemplate(defaultVal)
+		if err != nil {
+			return err
+		}
+		defaultValTyped, err := jsonschema.FromString(defaultVal, property.Type)
+		if err != nil {
+			return err
+		}
+		c.values[name] = defaultValTyped
 	}
 	return nil
 }
 
 // Prompts user for values for properties that do not have a value set yet
-func (c *config) promptForValues() error {
+func (c *config) promptForValues(r *renderer) error {
 	for _, p := range c.schema.OrderedProperties() {
 		name := p.Name
 		property := p.Schema
@@ -95,10 +107,19 @@ func (c *config) promptForValues() error {
 		var defaultVal string
 		var err error
 		if property.Default != nil {
-			defaultVal, err = jsonschema.ToString(property.Default, property.Type)
+			defaultValRaw, err := jsonschema.ToString(property.Default, property.Type)
 			if err != nil {
 				return err
 			}
+			defaultVal, err = r.executeTemplate(defaultValRaw)
+			if err != nil {
+				return err
+			}
+		}
+
+		description, err := r.executeTemplate(property.Description)
+		if err != nil {
+			return err
 		}
 
 		// Get user input by running the prompt
@@ -109,21 +130,15 @@ func (c *config) promptForValues() error {
 			if err != nil {
 				return err
 			}
-			userInput, err = cmdio.AskSelect(c.ctx, property.Description, enums)
+			userInput, err = cmdio.AskSelect(c.ctx, description, enums)
 			if err != nil {
 				return err
 			}
 		} else {
-			userInput, err = cmdio.Ask(c.ctx, property.Description, defaultVal)
+			userInput, err = cmdio.Ask(c.ctx, description, defaultVal)
 			if err != nil {
 				return err
 			}
-
-		}
-
-		// Validate the property matches any specified regex pattern.
-		if err := jsonschema.ValidatePatternMatch(name, userInput, property); err != nil {
-			return err
 		}
 
 		// Convert user input string back to a value
@@ -131,23 +146,28 @@ func (c *config) promptForValues() error {
 		if err != nil {
 			return err
 		}
+
+		// Validate the partial config based on this update
+		if err := c.schema.ValidateInstance(c.values); err != nil {
+			return err
+		}
 	}
 	return nil
 }
 
 // Prompt user for any missing config values. Assign default values if
 // terminal is not TTY
-func (c *config) promptOrAssignDefaultValues() error {
+func (c *config) promptOrAssignDefaultValues(r *renderer) error {
 	if cmdio.IsOutTTY(c.ctx) && cmdio.IsInTTY(c.ctx) {
-		return c.promptForValues()
+		return c.promptForValues(r)
 	}
-	return c.assignDefaultValues()
+	return c.assignDefaultValues(r)
 }
 
 // Validates the configuration. If passes, the configuration is ready to be used
 // to initialize the template.
 func (c *config) validate() error {
-	// All properties in the JSON schema should have a value defined.
+	// For final validation, all properties in the JSON schema should have a value defined.
 	c.schema.Required = maps.Keys(c.schema.Properties)
 	if err := c.schema.ValidateInstance(c.values); err != nil {
 		return fmt.Errorf("validation for template input parameters failed. %w", err)

libs/template/config_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/databricks/cli/cmd/root"
 	"github.com/databricks/cli/libs/jsonschema"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -52,11 +53,17 @@ func TestTemplateConfigAssignValuesFromFileDoesNotOverwriteExistingConfigs(t *te
 func TestTemplateConfigAssignDefaultValues(t *testing.T) {
 	c := testConfig(t)
 
-	err := c.assignDefaultValues()
+	ctx := context.Background()
+	ctx = root.SetWorkspaceClient(ctx, nil)
+	helpers := loadHelpers(ctx)
+	r, err := newRenderer(ctx, nil, helpers, "./testdata/template-in-path/template", "./testdata/template-in-path/library", t.TempDir())
+	require.NoError(t, err)
+
+	err = c.assignDefaultValues(r)
 	assert.NoError(t, err)
 
 	assert.Len(t, c.values, 2)
-	assert.Equal(t, "abc", c.values["string_val"])
+	assert.Equal(t, "my_file", c.values["string_val"])
 	assert.Equal(t, int64(123), c.values["int_val"])
 }
 
@@ -169,3 +176,16 @@ func TestTemplateEnumValidation(t *testing.T) {
 	}
 	assert.NoError(t, c.validate())
 }
+
+func TestAssignDefaultValuesWithTemplatedDefaults(t *testing.T) {
+	c := testConfig(t)
+	ctx := context.Background()
+	ctx = root.SetWorkspaceClient(ctx, nil)
+	helpers := loadHelpers(ctx)
+	r, err := newRenderer(ctx, nil, helpers, "./testdata/templated-defaults/template", "./testdata/templated-defaults/library", t.TempDir())
+	require.NoError(t, err)
+
+	err = c.assignDefaultValues(r)
+	assert.NoError(t, err)
+	assert.Equal(t, "my_file", c.values["string_val"])
+}

libs/template/helpers.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/url"
+	"os"
 	"regexp"
 	"text/template"
 
@@ -65,7 +66,7 @@ func loadHelpers(ctx context.Context) template.FuncMap {
 		// Get smallest node type (follows Terraform's GetSmallestNodeType)
 		"smallest_node_type": func() (string, error) {
 			if w.Config.Host == "" {
-				return "", errors.New("cannot determine target workspace, please first setup a configuration profile using 'databricks auth login'")
+				return "", errors.New("cannot determine target workspace, please first setup a configuration profile using 'databricks configure'")
 			}
 			if w.Config.IsAzure() {
 				return "Standard_D3_v2", nil
@@ -74,9 +75,12 @@ func loadHelpers(ctx context.Context) template.FuncMap {
 			}
 			return "i3.xlarge", nil
 		},
+		"path_separator": func() string {
+			return string(os.PathSeparator)
+		},
 		"workspace_host": func() (string, error) {
 			if w.Config.Host == "" {
-				return "", errors.New("cannot determine target workspace, please first setup a configuration profile using 'databricks auth login'")
+				return "", errors.New("cannot determine target workspace, please first setup a configuration profile using 'databricks configure'")
 			}
 			return w.Config.Host, nil
 		},

libs/template/materialize.go

@@ -56,23 +56,23 @@ func Materialize(ctx context.Context, configFilePath, templateRoot, outputDir st
 		}
 	}
 
-	// Prompt user for any missing config values. Assign default values if
-	// terminal is not TTY
-	err = config.promptOrAssignDefaultValues()
+	r, err := newRenderer(ctx, config.values, helpers, templatePath, libraryPath, outputDir)
 	if err != nil {
 		return err
 	}
 
+	// Prompt user for any missing config values. Assign default values if
+	// terminal is not TTY
+	err = config.promptOrAssignDefaultValues(r)
+	if err != nil {
+		return err
+	}
 	err = config.validate()
 	if err != nil {
 		return err
 	}
 
 	// Walk and render the template, since input configuration is complete
-	r, err := newRenderer(ctx, config.values, helpers, templatePath, libraryPath, outputDir)
-	if err != nil {
-		return err
-	}
 	err = r.walk()
 	if err != nil {
 		return err
@@ -82,7 +82,17 @@ func Materialize(ctx context.Context, configFilePath, templateRoot, outputDir st
 	if err != nil {
 		return err
 	}
+
+	success := config.schema.SuccessMessage
+	if success == "" {
 		cmdio.LogString(ctx, "✨ Successfully initialized template")
+	} else {
+		success, err = r.executeTemplate(success)
+		if err != nil {
+			return err
+		}
+		cmdio.LogString(ctx, success)
+	}
 	return nil
 }
 

libs/template/renderer.go

@@ -311,7 +311,7 @@ func (r *renderer) persistToDisk() error {
 		path := file.DstPath().absPath()
 		_, err := os.Stat(path)
 		if err == nil {
-			return fmt.Errorf("failed to persist to disk, conflict with existing file: %s", path)
+			return fmt.Errorf("failed to initialize template, one or more files already exist: %s", path)
 		}
 		if err != nil && !os.IsNotExist(err) {
 			return fmt.Errorf("error while verifying file %s does not already exist: %w", path, err)

libs/template/renderer_test.go

@@ -516,7 +516,7 @@ func TestRendererErrorOnConflictingFile(t *testing.T) {
 		},
 	}
 	err = r.persistToDisk()
-	assert.EqualError(t, err, fmt.Sprintf("failed to persist to disk, conflict with existing file: %s", filepath.Join(tmpDir, "a")))
+	assert.EqualError(t, err, fmt.Sprintf("failed to initialize template, one or more files already exist: %s", filepath.Join(tmpDir, "a")))
 }
 
 func TestRendererNoErrorOnConflictingFileIfSkipped(t *testing.T) {

libs/template/templates/default-python/databricks_template_schema.json

@@ -5,29 +5,30 @@
             "default": "my_project",
             "description": "Unique name for this project",
             "order": 1,
-            "pattern": "^[A-Za-z0-9_]*$",
-            "pattern_match_failure_message": "Must consist of letter and underscores only."
+            "pattern": "^[A-Za-z0-9_]+$",
+            "pattern_match_failure_message": "Name must consist of letters, numbers, and underscores."
         },
         "include_notebook": {
             "type": "string",
             "default": "yes",
             "enum": ["yes", "no"],
-            "description": "Include a stub (sample) notebook in 'my_project/src'",
+            "description": "Include a stub (sample) notebook in '{{.project_name}}{{path_separator}}src'",
             "order": 2
         },
         "include_dlt": {
             "type": "string",
             "default": "yes",
             "enum": ["yes", "no"],
-            "description": "Include a stub (sample) DLT pipeline in 'my_project/src'",
+            "description": "Include a stub (sample) Delta Live Tables pipeline in '{{.project_name}}{{path_separator}}src'",
             "order": 3
         },
         "include_python": {
             "type": "string",
             "default": "yes",
             "enum": ["yes", "no"],
-            "description": "Include a stub (sample) Python package in '{{.project_name}}/src'",
+            "description": "Include a stub (sample) Python package in '{{.project_name}}{{path_separator}}src'",
             "order": 4
         }
-    }
+    },
+    "success_message": "\n✨ Your new project has been created in the '{{.project_name}}' directory!\n\nPlease refer to the README.md of your project for further instructions on getting started.\nOr read the documentation on Databricks Asset Bundles at https://docs.databricks.com/dev-tools/bundles/index.html."
 }

libs/template/testdata/config-test-schema/test-schema.json

@@ -12,7 +12,7 @@
         },
         "string_val": {
             "type": "string",
-            "default": "abc"
+            "default": "{{template \"file_name\"}}"
         }
     }
 }

libs/template/testdata/templated-defaults/library/my_funcs.tmpl

@@ -0,0 +1,7 @@
+{{define "dir_name" -}}
+my_directory
+{{- end}}
+
+{{define "file_name" -}}
+my_file
+{{- end}}