Move bundle loading functions to top level (#181)

We intend to let non-bundle commands use bundle configuration for their
operating context (workspace, auth, default cluster, etc).

As such, all commands must first try to load a bundle configuration.
If there is no bundle they can fall back on taking their operating
context from command line flags and the environment.

This is on top of #180.

cmd/bundle/debug/whoami.go

@@ -4,14 +4,14 @@ import (
 	"fmt"
 
 	"github.com/databricks/bricks/bundle"
-	parent "github.com/databricks/bricks/cmd/bundle"
+	"github.com/databricks/bricks/cmd/root"
 	"github.com/spf13/cobra"
 )
 
 var whoamiCmd = &cobra.Command{
 	Use: "whoami",
 
-	PreRunE: parent.ConfigureBundle,
+	PreRunE: root.MustConfigureBundle,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		ctx := cmd.Context()
 		w := bundle.Get(ctx).WorkspaceClient()

cmd/bundle/deploy.go

@@ -3,6 +3,7 @@ package bundle
 import (
 	"github.com/databricks/bricks/bundle"
 	"github.com/databricks/bricks/bundle/phases"
+	"github.com/databricks/bricks/cmd/root"
 	"github.com/spf13/cobra"
 )
 
@@ -10,7 +11,7 @@ var deployCmd = &cobra.Command{
 	Use:   "deploy",
 	Short: "Deploy bundle",
 
-	PreRunE: ConfigureBundle,
+	PreRunE: root.MustConfigureBundle,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		b := bundle.Get(cmd.Context())
 		return bundle.Apply(cmd.Context(), b, []bundle.Mutator{

cmd/bundle/environment.go

@@ -1,24 +0,0 @@
-package bundle
-
-import (
-	"os"
-
-	"github.com/spf13/cobra"
-)
-
-const envName = "DATABRICKS_BUNDLE_ENV"
-
-// getEnvironment returns the name of the environment to operate in.
-func getEnvironment(cmd *cobra.Command) (value string) {
-	// The command line flag takes precedence.
-	flag := cmd.Flag("environment")
-	if flag != nil {
-		value = flag.Value.String()
-		if value != "" {
-			return
-		}
-	}
-
-	// If it's not set, use the environment variable.
-	return os.Getenv(envName)
-}

cmd/bundle/root.go

@@ -1,8 +1,6 @@
 package bundle
 
 import (
-	"github.com/databricks/bricks/bundle"
-	"github.com/databricks/bricks/bundle/config/mutator"
 	"github.com/databricks/bricks/cmd/root"
 	"github.com/spf13/cobra"
 )
@@ -13,39 +11,10 @@ var rootCmd = &cobra.Command{
 	Short: "Databricks Application Bundles",
 }
 
-// ConfigureBundle loads the bundle configuration
-// and configures it on the command's context.
-func ConfigureBundle(cmd *cobra.Command, args []string) error {
-	ctx := cmd.Context()
-	b, err := bundle.MustLoad()
-	if err != nil {
-		return err
-	}
-
-	ms := mutator.DefaultMutators()
-	env := getEnvironment(cmd)
-	if env == "" {
-		ms = append(ms, mutator.SelectDefaultEnvironment())
-	} else {
-		ms = append(ms, mutator.SelectEnvironment(env))
-	}
-
-	err = bundle.Apply(ctx, b, ms)
-	if err != nil {
-		return err
-	}
-
-	cmd.SetContext(bundle.Context(ctx, b))
-	return nil
-}
-
 func AddCommand(cmd *cobra.Command) {
 	rootCmd.AddCommand(cmd)
 }
 
 func init() {
-	// All bundle commands take an "environment" parameter.
-	rootCmd.PersistentFlags().StringP("environment", "e", "", "Environment to use")
-	// Add to top level root.
 	root.RootCmd.AddCommand(rootCmd)
 }

cmd/bundle/run.go

@@ -5,6 +5,7 @@ import (
 	"github.com/databricks/bricks/bundle/deploy/terraform"
 	"github.com/databricks/bricks/bundle/phases"
 	"github.com/databricks/bricks/bundle/run"
+	"github.com/databricks/bricks/cmd/root"
 	"github.com/spf13/cobra"
 )
 
@@ -15,7 +16,7 @@ var runCmd = &cobra.Command{
 	Short: "Run a workload (e.g. a job or a pipeline)",
 
 	Args:    cobra.ExactArgs(1),
-	PreRunE: ConfigureBundle,
+	PreRunE: root.MustConfigureBundle,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		b := bundle.Get(cmd.Context())
 		err := bundle.Apply(cmd.Context(), b, []bundle.Mutator{

cmd/bundle/validate.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/databricks/bricks/bundle"
 	"github.com/databricks/bricks/bundle/phases"
+	"github.com/databricks/bricks/cmd/root"
 	"github.com/spf13/cobra"
 )
 
@@ -12,7 +13,7 @@ var validateCmd = &cobra.Command{
 	Use:   "validate",
 	Short: "Validate configuration",
 
-	PreRunE: ConfigureBundle,
+	PreRunE: root.MustConfigureBundle,
 	RunE: func(cmd *cobra.Command, args []string) error {
 		b := bundle.Get(cmd.Context())
 		err := bundle.Apply(cmd.Context(), b, []bundle.Mutator{

cmd/root/bundle.go

@@ -0,0 +1,72 @@
+package root
+
+import (
+	"os"
+
+	"github.com/databricks/bricks/bundle"
+	"github.com/databricks/bricks/bundle/config/mutator"
+	"github.com/spf13/cobra"
+)
+
+const envName = "DATABRICKS_BUNDLE_ENV"
+
+// getEnvironment returns the name of the environment to operate in.
+func getEnvironment(cmd *cobra.Command) (value string) {
+	// The command line flag takes precedence.
+	flag := cmd.Flag("environment")
+	if flag != nil {
+		value = flag.Value.String()
+		if value != "" {
+			return
+		}
+	}
+
+	// If it's not set, use the environment variable.
+	return os.Getenv(envName)
+}
+
+// configureBundle loads the bundle configuration and configures it on the command's context.
+func configureBundle(cmd *cobra.Command, args []string, load func() (*bundle.Bundle, error)) error {
+	b, err := load()
+	if err != nil {
+		return err
+	}
+
+	// No bundle is fine in case of `TryConfigureBundle`.
+	if b == nil {
+		return nil
+	}
+
+	ms := mutator.DefaultMutators()
+	env := getEnvironment(cmd)
+	if env == "" {
+		ms = append(ms, mutator.SelectDefaultEnvironment())
+	} else {
+		ms = append(ms, mutator.SelectEnvironment(env))
+	}
+
+	ctx := cmd.Context()
+	err = bundle.Apply(ctx, b, ms)
+	if err != nil {
+		return err
+	}
+
+	cmd.SetContext(bundle.Context(ctx, b))
+	return nil
+}
+
+// MustConfigureBundle configures a bundle on the command context.
+func MustConfigureBundle(cmd *cobra.Command, args []string) error {
+	return configureBundle(cmd, args, bundle.MustLoad)
+}
+
+// TryConfigureBundle configures a bundle on the command context
+// if there is one, but doesn't fail if there isn't one.
+func TryConfigureBundle(cmd *cobra.Command, args []string) error {
+	return configureBundle(cmd, args, bundle.TryLoad)
+}
+
+func init() {
+	// To operate in the context of a bundle, all commands must take an "environment" parameter.
+	RootCmd.PersistentFlags().StringP("environment", "e", "", "bundle environment to use (if applicable)")
+}