Merge 4233a7c292 into abfd1713e0

## Changes

Users can configure the bundle to not synchronize any files with:
```yaml
sync:
  paths: []
```

If it is explicitly configured as an empty list, the validate command
must not warn about not having any files to synchronize. The warning
exists to alert users who are unintentionally not synchronizing any
files (they might have a `.gitignore` pattern that matches everything).

Closes #1663.

## Tests

* New unit test.

bundle/config/mutator/translate_paths.go

@@ -126,7 +126,33 @@ func (t *translateContext) rewritePath(
 func (t *translateContext) translateNotebookPath(literal, localFullPath, localRelPath, remotePath string) (string, error) {
 	nb, _, err := notebook.DetectWithFS(t.b.SyncRoot, filepath.ToSlash(localRelPath))
 	if errors.Is(err, fs.ErrNotExist) {
-		return "", fmt.Errorf("notebook %s not found", literal)
+		if filepath.Ext(localFullPath) != notebook.ExtensionNone {
+			return "", fmt.Errorf("notebook %s not found", literal)
+		}
+
+		extensions := []string{
+			notebook.ExtensionPython,
+			notebook.ExtensionR,
+			notebook.ExtensionScala,
+			notebook.ExtensionSql,
+			notebook.ExtensionJupyter,
+		}
+
+		// Check whether a file with a notebook extension already exists. This
+		// way we can provide a more targeted error message.
+		for _, ext := range extensions {
+			literalWithExt := literal + ext
+			localRelPathWithExt := filepath.ToSlash(localRelPath + ext)
+			if _, err := fs.Stat(t.b.SyncRoot, localRelPathWithExt); err == nil {
+				return "", fmt.Errorf(`notebook %s not found. Did you mean %s?
+Local notebook references are expected to contain one of the following
+file extensions: [%s]`, literal, literalWithExt, strings.Join(extensions, ", "))
+			}
+		}
+
+		// Return a generic error message if no matching possible file is found.
+		return "", fmt.Errorf(`notebook %s not found. Local notebook references are expected
+to contain one of the following file extensions: [%s]`, literal, strings.Join(extensions, ", "))
 	}
 	if err != nil {
 		return "", fmt.Errorf("unable to determine if %s is a notebook: %w", localFullPath, err)

bundle/config/mutator/translate_paths_test.go

@@ -2,6 +2,7 @@ package mutator_test
 
 import (
 	"context"
+	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -508,6 +509,59 @@ func TestPipelineNotebookDoesNotExistError(t *testing.T) {
 	assert.EqualError(t, diags.Error(), "notebook ./doesnt_exist.py not found")
 }
 
+func TestPipelineNotebookDoesNotExistErrorWithoutExtension(t *testing.T) {
+	for _, ext := range []string{
+		".py",
+		".r",
+		".scala",
+		".sql",
+		".ipynb",
+		"",
+	} {
+		t.Run("case_"+ext, func(t *testing.T) {
+			dir := t.TempDir()
+
+			if ext != "" {
+				touchEmptyFile(t, filepath.Join(dir, "foo"+ext))
+			}
+
+			b := &bundle.Bundle{
+				SyncRootPath: dir,
+				SyncRoot:     vfs.MustNew(dir),
+				Config: config.Root{
+					Resources: config.Resources{
+						Pipelines: map[string]*resources.Pipeline{
+							"pipeline": {
+								PipelineSpec: &pipelines.PipelineSpec{
+									Libraries: []pipelines.PipelineLibrary{
+										{
+											Notebook: &pipelines.NotebookLibrary{
+												Path: "./foo",
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			bundletest.SetLocation(b, ".", []dyn.Location{{File: filepath.Join(dir, "fake.yml")}})
+			diags := bundle.Apply(context.Background(), b, mutator.TranslatePaths())
+
+			if ext == "" {
+				assert.EqualError(t, diags.Error(), `notebook ./foo not found. Local notebook references are expected
+to contain one of the following file extensions: [.py, .r, .scala, .sql, .ipynb]`)
+			} else {
+				assert.EqualError(t, diags.Error(), fmt.Sprintf(`notebook ./foo not found. Did you mean ./foo%s?
+Local notebook references are expected to contain one of the following
+file extensions: [.py, .r, .scala, .sql, .ipynb]`, ext))
+			}
+		})
+	}
+}
+
 func TestPipelineFileDoesNotExistError(t *testing.T) {
 	dir := t.TempDir()
 

bundle/config/validate/files_to_sync.go

@@ -21,6 +21,12 @@ func (v *filesToSync) Name() string {
 }
 
 func (v *filesToSync) Apply(ctx context.Context, rb bundle.ReadOnlyBundle) diag.Diagnostics {
+	// The user may be intentional about not synchronizing any files.
+	// In this case, we should not show any warnings.
+	if len(rb.Config().Sync.Paths) == 0 {
+		return nil
+	}
+
 	sync, err := files.GetSync(ctx, rb)
 	if err != nil {
 		return diag.FromErr(err)
@@ -31,6 +37,7 @@ func (v *filesToSync) Apply(ctx context.Context, rb bundle.ReadOnlyBundle) diag.
 		return diag.FromErr(err)
 	}
 
+	// If there are files to sync, we don't need to show any warnings.
 	if len(fl) != 0 {
 		return nil
 	}

bundle/config/validate/files_to_sync_test.go

@@ -0,0 +1,105 @@
+package validate
+
+import (
+	"context"
+	"testing"
+
+	"github.com/databricks/cli/bundle"
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/internal/testutil"
+	"github.com/databricks/cli/libs/diag"
+	"github.com/databricks/cli/libs/vfs"
+	sdkconfig "github.com/databricks/databricks-sdk-go/config"
+	"github.com/databricks/databricks-sdk-go/experimental/mocks"
+	"github.com/databricks/databricks-sdk-go/service/iam"
+	"github.com/databricks/databricks-sdk-go/service/workspace"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFilesToSync_NoPaths(t *testing.T) {
+	b := &bundle.Bundle{
+		Config: config.Root{
+			Sync: config.Sync{
+				Paths: []string{},
+			},
+		},
+	}
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	assert.Empty(t, diags)
+}
+
+func setupBundleForFilesToSyncTest(t *testing.T) *bundle.Bundle {
+	dir := t.TempDir()
+
+	testutil.Touch(t, dir, "file1")
+	testutil.Touch(t, dir, "file2")
+
+	b := &bundle.Bundle{
+		BundleRootPath: dir,
+		BundleRoot:     vfs.MustNew(dir),
+		SyncRootPath:   dir,
+		SyncRoot:       vfs.MustNew(dir),
+		Config: config.Root{
+			Bundle: config.Bundle{
+				Target: "default",
+			},
+			Workspace: config.Workspace{
+				FilePath: "/this/doesnt/matter",
+				CurrentUser: &config.User{
+					User: &iam.User{},
+				},
+			},
+			Sync: config.Sync{
+				// Paths are relative to [SyncRootPath].
+				Paths: []string{"."},
+			},
+		},
+	}
+
+	m := mocks.NewMockWorkspaceClient(t)
+	m.WorkspaceClient.Config = &sdkconfig.Config{
+		Host: "https://foo.com",
+	}
+
+	// The initialization logic in [sync.New] performs a check on the destination path.
+	// Removing this check at initialization time is tbd...
+	m.GetMockWorkspaceAPI().EXPECT().GetStatusByPath(mock.Anything, "/this/doesnt/matter").Return(&workspace.ObjectInfo{
+		ObjectType: workspace.ObjectTypeDirectory,
+	}, nil)
+
+	b.SetWorkpaceClient(m.WorkspaceClient)
+	return b
+}
+
+func TestFilesToSync_EverythingIgnored(t *testing.T) {
+	b := setupBundleForFilesToSyncTest(t)
+
+	// Ignore all files.
+	testutil.WriteFile(t, "*\n.*\n", b.BundleRootPath, ".gitignore")
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	require.Equal(t, 1, len(diags))
+	assert.Equal(t, diag.Warning, diags[0].Severity)
+	assert.Equal(t, "There are no files to sync, please check your .gitignore", diags[0].Summary)
+}
+
+func TestFilesToSync_EverythingExcluded(t *testing.T) {
+	b := setupBundleForFilesToSyncTest(t)
+
+	// Exclude all files.
+	b.Config.Sync.Exclude = []string{"*"}
+
+	ctx := context.Background()
+	rb := bundle.ReadOnly(b)
+	diags := bundle.ApplyReadOnly(ctx, rb, FilesToSync())
+	require.Equal(t, 1, len(diags))
+	assert.Equal(t, diag.Warning, diags[0].Severity)
+	assert.Equal(t, "There are no files to sync, please check your .gitignore and sync.exclude configuration", diags[0].Summary)
+}

bundle/config/validate/single_node_cluster.go

@@ -0,0 +1,135 @@
+package validate
+
+import (
+	"context"
+	"strings"
+
+	"github.com/databricks/cli/bundle"
+	"github.com/databricks/cli/libs/diag"
+	"github.com/databricks/cli/libs/dyn"
+	"github.com/databricks/cli/libs/dyn/convert"
+	"github.com/databricks/cli/libs/log"
+)
+
+// Validates that any single node clusters defined in the bundle are correctly configured.
+func SingleNodeCluster() bundle.ReadOnlyMutator {
+	return &singleNodeCluster{}
+}
+
+type singleNodeCluster struct{}
+
+func (m *singleNodeCluster) Name() string {
+	return "validate:SingleNodeCluster"
+}
+
+const singleNodeWarningDetail = `num_workers should be 0 only for single-node clusters. To create a
+valid single node cluster please ensure that the following properties
+are correctly set in the cluster specification:
+
+  spark_conf:
+    spark.databricks.cluster.profile: singleNode
+    spark.master: local[*]
+
+  custom_tags:
+    ResourceClass: SingleNode
+  `
+
+const singleNodeWarningSummary = `Single node cluster is not correctly configured`
+
+func showSingleNodeClusterWarning(ctx context.Context, v dyn.Value) bool {
+	// Check if the user has explicitly set the num_workers to 0. Skip the warning
+	// if that's not the case.
+	numWorkers, ok := v.Get("num_workers").AsInt()
+	if !ok || numWorkers > 0 {
+		return false
+	}
+
+	// Convenient type that contains the common fields from compute.ClusterSpec and
+	// pipelines.PipelineCluster that we are interested in.
+	type ClusterConf struct {
+		SparkConf  map[string]string `json:"spark_conf"`
+		CustomTags map[string]string `json:"custom_tags"`
+		PolicyId   string            `json:"policy_id"`
+	}
+
+	conf := &ClusterConf{}
+	err := convert.ToTyped(conf, v)
+	if err != nil {
+		return false
+	}
+
+	// If the policy id is set, we don't want to show the warning. This is because
+	// the user might have configured `spark_conf` and `custom_tags` correctly
+	// in their cluster policy.
+	if conf.PolicyId != "" {
+		return false
+	}
+
+	profile, ok := conf.SparkConf["spark.databricks.cluster.profile"]
+	if !ok {
+		log.Warnf(ctx, "spark_conf spark.databricks.cluster.profile not found in single-node cluster spec")
+		return true
+	}
+	if profile != "singleNode" {
+		log.Warnf(ctx, "spark_conf spark.databricks.cluster.profile is not singleNode in single-node cluster spec: %s", profile)
+		return true
+	}
+
+	master, ok := conf.SparkConf["spark.master"]
+	if !ok {
+		log.Warnf(ctx, "spark_conf spark.master not found in single-node cluster spec")
+		return true
+	}
+	if !strings.HasPrefix(master, "local") {
+		log.Warnf(ctx, "spark_conf spark.master does not start with local in single-node cluster spec: %s", master)
+		return true
+	}
+
+	resourceClass, ok := conf.CustomTags["ResourceClass"]
+	if !ok {
+		log.Warnf(ctx, "custom_tag ResourceClass not found in single-node cluster spec")
+		return true
+	}
+	if resourceClass != "SingleNode" {
+		log.Warnf(ctx, "custom_tag ResourceClass is not SingleNode in single-node cluster spec: %s", resourceClass)
+		return true
+	}
+
+	return false
+}
+
+func (m *singleNodeCluster) Apply(ctx context.Context, rb bundle.ReadOnlyBundle) diag.Diagnostics {
+	diags := diag.Diagnostics{}
+
+	patterns := []dyn.Pattern{
+		// Interactive clusters
+		dyn.NewPattern(dyn.Key("resources"), dyn.Key("clusters"), dyn.AnyKey()),
+		// Job clusters
+		dyn.NewPattern(dyn.Key("resources"), dyn.Key("jobs"), dyn.AnyKey(), dyn.Key("job_clusters"), dyn.AnyIndex(), dyn.Key("new_cluster")),
+		// Job task clusters
+		dyn.NewPattern(dyn.Key("resources"), dyn.Key("jobs"), dyn.AnyKey(), dyn.Key("tasks"), dyn.AnyIndex(), dyn.Key("new_cluster")),
+		// Pipeline clusters
+		dyn.NewPattern(dyn.Key("resources"), dyn.Key("pipelines"), dyn.AnyKey(), dyn.Key("clusters"), dyn.AnyIndex()),
+	}
+
+	for _, p := range patterns {
+		_, err := dyn.MapByPattern(rb.Config().Value(), p, func(p dyn.Path, v dyn.Value) (dyn.Value, error) {
+			warning := diag.Diagnostic{
+				Severity:  diag.Warning,
+				Summary:   singleNodeWarningSummary,
+				Detail:    singleNodeWarningDetail,
+				Locations: v.Locations(),
+				Paths:     []dyn.Path{p},
+			}
+
+			if showSingleNodeClusterWarning(ctx, v) {
+				diags = append(diags, warning)
+			}
+			return v, nil
+		})
+		if err != nil {
+			log.Debugf(ctx, "Error while applying single node cluster validation: %s", err)
+		}
+	}
+	return diags
+}

bundle/config/validate/single_node_cluster_test.go

@@ -0,0 +1,440 @@
+package validate
+
+import (
+	"context"
+	"testing"
+
+	"github.com/databricks/cli/bundle"
+	"github.com/databricks/cli/bundle/config"
+	"github.com/databricks/cli/bundle/config/resources"
+	"github.com/databricks/cli/bundle/internal/bundletest"
+	"github.com/databricks/cli/libs/diag"
+	"github.com/databricks/cli/libs/dyn"
+	"github.com/databricks/databricks-sdk-go/service/compute"
+	"github.com/databricks/databricks-sdk-go/service/jobs"
+	"github.com/databricks/databricks-sdk-go/service/pipelines"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestValidateSingleNodeClusterFail(t *testing.T) {
+	failCases := []struct {
+		name       string
+		sparkConf  map[string]string
+		customTags map[string]string
+	}{
+		{
+			name: "no tags or conf",
+		},
+		{
+			name: "no tags",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+				"spark.master":                     "local[*]",
+			},
+		},
+		{
+			name:       "no conf",
+			customTags: map[string]string{"ResourceClass": "SingleNode"},
+		},
+		{
+			name: "invalid spark cluster profile",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "invalid",
+				"spark.master":                     "local[*]",
+			},
+			customTags: map[string]string{"ResourceClass": "SingleNode"},
+		},
+		{
+			name: "invalid spark.master",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+				"spark.master":                     "invalid",
+			},
+			customTags: map[string]string{"ResourceClass": "SingleNode"},
+		},
+		{
+			name: "invalid tags",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+				"spark.master":                     "local[*]",
+			},
+			customTags: map[string]string{"ResourceClass": "invalid"},
+		},
+		{
+			name: "missing ResourceClass tag",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+				"spark.master":                     "local[*]",
+			},
+			customTags: map[string]string{"what": "ever"},
+		},
+		{
+			name: "missing spark.master",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+			},
+			customTags: map[string]string{"ResourceClass": "SingleNode"},
+		},
+		{
+			name: "missing spark.databricks.cluster.profile",
+			sparkConf: map[string]string{
+				"spark.master": "local[*]",
+			},
+			customTags: map[string]string{"ResourceClass": "SingleNode"},
+		},
+	}
+
+	ctx := context.Background()
+
+	// Interactive clusters.
+	for _, tc := range failCases {
+		t.Run("interactive_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Clusters: map[string]*resources.Cluster{
+							"foo": {
+								ClusterSpec: &compute.ClusterSpec{
+									SparkConf:  tc.sparkConf,
+									CustomTags: tc.customTags,
+								},
+							},
+						},
+					},
+				},
+			}
+
+			bundletest.SetLocation(b, "resources.clusters.foo", []dyn.Location{{File: "a.yml", Line: 1, Column: 1}})
+
+			// We can't set num_workers to 0 explicitly in the typed configuration.
+			// Do it on the dyn.Value directly.
+			bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+				return dyn.Set(v, "resources.clusters.foo.num_workers", dyn.V(0))
+			})
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Equal(t, diag.Diagnostics{
+				{
+					Severity:  diag.Warning,
+					Summary:   singleNodeWarningSummary,
+					Detail:    singleNodeWarningDetail,
+					Locations: []dyn.Location{{File: "a.yml", Line: 1, Column: 1}},
+					Paths:     []dyn.Path{dyn.NewPath(dyn.Key("resources"), dyn.Key("clusters"), dyn.Key("foo"))},
+				},
+			}, diags)
+		})
+	}
+
+	// Job clusters.
+	for _, tc := range failCases {
+		t.Run("job_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Jobs: map[string]*resources.Job{
+							"foo": {
+								JobSettings: &jobs.JobSettings{
+									JobClusters: []jobs.JobCluster{
+										{
+											NewCluster: compute.ClusterSpec{
+												ClusterName: "my_cluster",
+												SparkConf:   tc.sparkConf,
+												CustomTags:  tc.customTags,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			bundletest.SetLocation(b, "resources.jobs.foo.job_clusters[0].new_cluster", []dyn.Location{{File: "b.yml", Line: 1, Column: 1}})
+
+			// We can't set num_workers to 0 explicitly in the typed configuration.
+			// Do it on the dyn.Value directly.
+			bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+				return dyn.Set(v, "resources.jobs.foo.job_clusters[0].new_cluster.num_workers", dyn.V(0))
+			})
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Equal(t, diag.Diagnostics{
+				{
+					Severity:  diag.Warning,
+					Summary:   singleNodeWarningSummary,
+					Detail:    singleNodeWarningDetail,
+					Locations: []dyn.Location{{File: "b.yml", Line: 1, Column: 1}},
+					Paths:     []dyn.Path{dyn.MustPathFromString("resources.jobs.foo.job_clusters[0].new_cluster")},
+				},
+			}, diags)
+
+		})
+	}
+
+	// Job task clusters.
+	for _, tc := range failCases {
+		t.Run("task_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Jobs: map[string]*resources.Job{
+							"foo": {
+								JobSettings: &jobs.JobSettings{
+									Tasks: []jobs.Task{
+										{
+											NewCluster: &compute.ClusterSpec{
+												ClusterName: "my_cluster",
+												SparkConf:   tc.sparkConf,
+												CustomTags:  tc.customTags,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			bundletest.SetLocation(b, "resources.jobs.foo.tasks[0].new_cluster", []dyn.Location{{File: "c.yml", Line: 1, Column: 1}})
+
+			// We can't set num_workers to 0 explicitly in the typed configuration.
+			// Do it on the dyn.Value directly.
+			bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+				return dyn.Set(v, "resources.jobs.foo.tasks[0].new_cluster.num_workers", dyn.V(0))
+			})
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Equal(t, diag.Diagnostics{
+				{
+					Severity:  diag.Warning,
+					Summary:   singleNodeWarningSummary,
+					Detail:    singleNodeWarningDetail,
+					Locations: []dyn.Location{{File: "c.yml", Line: 1, Column: 1}},
+					Paths:     []dyn.Path{dyn.MustPathFromString("resources.jobs.foo.tasks[0].new_cluster")},
+				},
+			}, diags)
+		})
+	}
+
+	// Pipeline clusters.
+	for _, tc := range failCases {
+		t.Run("pipeline_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Pipelines: map[string]*resources.Pipeline{
+							"foo": {
+								PipelineSpec: &pipelines.PipelineSpec{
+									Clusters: []pipelines.PipelineCluster{
+										{
+											SparkConf:  tc.sparkConf,
+											CustomTags: tc.customTags,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			bundletest.SetLocation(b, "resources.pipelines.foo.clusters[0]", []dyn.Location{{File: "d.yml", Line: 1, Column: 1}})
+
+			// We can't set num_workers to 0 explicitly in the typed configuration.
+			// Do it on the dyn.Value directly.
+			bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+				return dyn.Set(v, "resources.pipelines.foo.clusters[0].num_workers", dyn.V(0))
+			})
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Equal(t, diag.Diagnostics{
+				{
+					Severity:  diag.Warning,
+					Summary:   singleNodeWarningSummary,
+					Detail:    singleNodeWarningDetail,
+					Locations: []dyn.Location{{File: "d.yml", Line: 1, Column: 1}},
+					Paths:     []dyn.Path{dyn.MustPathFromString("resources.pipelines.foo.clusters[0]")},
+				},
+			}, diags)
+		})
+	}
+
+}
+
+func TestValidateSingleNodeClusterPass(t *testing.T) {
+	zero := 0
+	one := 1
+
+	passCases := []struct {
+		name       string
+		numWorkers *int
+		sparkConf  map[string]string
+		customTags map[string]string
+		policyId   string
+	}{
+		{
+			name: "single node cluster",
+			sparkConf: map[string]string{
+				"spark.databricks.cluster.profile": "singleNode",
+				"spark.master":                     "local[*]",
+			},
+			customTags: map[string]string{
+				"ResourceClass": "SingleNode",
+			},
+			numWorkers: &zero,
+		},
+		{
+			name:       "num workers is not zero",
+			numWorkers: &one,
+		},
+		{
+			name: "num workers is not set",
+		},
+		{
+			name:       "policy id is not empty",
+			policyId:   "policy-abc",
+			numWorkers: &zero,
+		},
+	}
+
+	ctx := context.Background()
+
+	// Interactive clusters.
+	for _, tc := range passCases {
+		t.Run("interactive_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Clusters: map[string]*resources.Cluster{
+							"foo": {
+								ClusterSpec: &compute.ClusterSpec{
+									SparkConf:  tc.sparkConf,
+									CustomTags: tc.customTags,
+									PolicyId:   tc.policyId,
+								},
+							},
+						},
+					},
+				},
+			}
+
+			if tc.numWorkers != nil {
+				bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+					return dyn.Set(v, "resources.clusters.foo.num_workers", dyn.V(*tc.numWorkers))
+				})
+			}
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Empty(t, diags)
+		})
+	}
+
+	// Job clusters.
+	for _, tc := range passCases {
+		t.Run("job_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Jobs: map[string]*resources.Job{
+							"foo": {
+								JobSettings: &jobs.JobSettings{
+									JobClusters: []jobs.JobCluster{
+										{
+											NewCluster: compute.ClusterSpec{
+												ClusterName: "my_cluster",
+												SparkConf:   tc.sparkConf,
+												CustomTags:  tc.customTags,
+												PolicyId:    tc.policyId,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			if tc.numWorkers != nil {
+				bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+					return dyn.Set(v, "resources.jobs.foo.job_clusters[0].new_cluster.num_workers", dyn.V(*tc.numWorkers))
+				})
+			}
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Empty(t, diags)
+		})
+	}
+
+	// Job task clusters.
+	for _, tc := range passCases {
+		t.Run("task_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Jobs: map[string]*resources.Job{
+							"foo": {
+								JobSettings: &jobs.JobSettings{
+									Tasks: []jobs.Task{
+										{
+											NewCluster: &compute.ClusterSpec{
+												ClusterName: "my_cluster",
+												SparkConf:   tc.sparkConf,
+												CustomTags:  tc.customTags,
+												PolicyId:    tc.policyId,
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			if tc.numWorkers != nil {
+				bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+					return dyn.Set(v, "resources.jobs.foo.tasks[0].new_cluster.num_workers", dyn.V(*tc.numWorkers))
+				})
+			}
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Empty(t, diags)
+		})
+	}
+
+	// Pipeline clusters.
+	for _, tc := range passCases {
+		t.Run("pipeline_"+tc.name, func(t *testing.T) {
+			b := &bundle.Bundle{
+				Config: config.Root{
+					Resources: config.Resources{
+						Pipelines: map[string]*resources.Pipeline{
+							"foo": {
+								PipelineSpec: &pipelines.PipelineSpec{
+									Clusters: []pipelines.PipelineCluster{
+										{
+											SparkConf:  tc.sparkConf,
+											CustomTags: tc.customTags,
+											PolicyId:   tc.policyId,
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			}
+
+			if tc.numWorkers != nil {
+				bundletest.Mutate(t, b, func(v dyn.Value) (dyn.Value, error) {
+					return dyn.Set(v, "resources.pipelines.foo.clusters[0].num_workers", dyn.V(*tc.numWorkers))
+				})
+			}
+
+			diags := bundle.ApplyReadOnly(ctx, bundle.ReadOnly(b), SingleNodeCluster())
+			assert.Empty(t, diags)
+		})
+	}
+}

bundle/config/validate/validate.go

@@ -36,6 +36,7 @@ func (v *validate) Apply(ctx context.Context, b *bundle.Bundle) diag.Diagnostics
 		ValidateSyncPatterns(),
 		JobTaskClusterSpec(),
 		ValidateFolderPermissions(),
+		SingleNodeCluster(),
 	))
 }
 

bundle/config/variable/lookup.go

@@ -22,6 +22,8 @@ type Lookup struct {
 
 	Metastore string `json:"metastore,omitempty"`
 
+	NotificationDestination string `json:"notification_destination,omitempty"`
+
 	Pipeline string `json:"pipeline,omitempty"`
 
 	Query string `json:"query,omitempty"`
@@ -63,6 +65,9 @@ func (l *Lookup) constructResolver() (resolver, error) {
 	if l.Metastore != "" {
 		resolvers = append(resolvers, resolveMetastore{name: l.Metastore})
 	}
+	if l.NotificationDestination != "" {
+		resolvers = append(resolvers, resolveNotificationDestination{name: l.NotificationDestination})
+	}
 	if l.Pipeline != "" {
 		resolvers = append(resolvers, resolvePipeline{name: l.Pipeline})
 	}

bundle/config/variable/resolve_notification_destination.go

@@ -0,0 +1,46 @@
+package variable
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/databricks/databricks-sdk-go"
+	"github.com/databricks/databricks-sdk-go/service/settings"
+)
+
+type resolveNotificationDestination struct {
+	name string
+}
+
+func (l resolveNotificationDestination) Resolve(ctx context.Context, w *databricks.WorkspaceClient) (string, error) {
+	result, err := w.NotificationDestinations.ListAll(ctx, settings.ListNotificationDestinationsRequest{
+		// The default page size for this API is 20.
+		// We use a higher value to make fewer API calls.
+		PageSize: 200,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	// Collect all notification destinations with the given name.
+	var entities []settings.ListNotificationDestinationsResult
+	for _, entity := range result {
+		if entity.DisplayName == l.name {
+			entities = append(entities, entity)
+		}
+	}
+
+	// Return the ID of the first matching notification destination.
+	switch len(entities) {
+	case 0:
+		return "", fmt.Errorf("notification destination named %q does not exist", l.name)
+	case 1:
+		return entities[0].Id, nil
+	default:
+		return "", fmt.Errorf("there are %d instances of clusters named %q", len(entities), l.name)
+	}
+}
+
+func (l resolveNotificationDestination) String() string {
+	return fmt.Sprintf("notification-destination: %s", l.name)
+}

bundle/config/variable/resolve_notification_destination_test.go

@@ -0,0 +1,82 @@
+package variable
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	"github.com/databricks/databricks-sdk-go/experimental/mocks"
+	"github.com/databricks/databricks-sdk-go/service/settings"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestResolveNotificationDestination_ResolveSuccess(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{
+			{Id: "1234", DisplayName: "destination"},
+		}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	result, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.NoError(t, err)
+	assert.Equal(t, "1234", result)
+}
+
+func TestResolveNotificationDestination_ResolveError(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return(nil, fmt.Errorf("bad"))
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	assert.ErrorContains(t, err, "bad")
+}
+
+func TestResolveNotificationDestination_ResolveNotFound(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.Error(t, err)
+	assert.ErrorContains(t, err, `notification destination named "destination" does not exist`)
+}
+
+func TestResolveNotificationDestination_ResolveMultiple(t *testing.T) {
+	m := mocks.NewMockWorkspaceClient(t)
+
+	api := m.GetMockNotificationDestinationsAPI()
+	api.EXPECT().
+		ListAll(mock.Anything, mock.Anything).
+		Return([]settings.ListNotificationDestinationsResult{
+			{Id: "1234", DisplayName: "destination"},
+			{Id: "5678", DisplayName: "destination"},
+		}, nil)
+
+	ctx := context.Background()
+	l := resolveNotificationDestination{name: "destination"}
+	_, err := l.Resolve(ctx, m.WorkspaceClient)
+	require.Error(t, err)
+	assert.ErrorContains(t, err, `there are 2 instances of clusters named "destination"`)
+}
+
+func TestResolveNotificationDestination_String(t *testing.T) {
+	l := resolveNotificationDestination{name: "name"}
+	assert.Equal(t, "notification-destination: name", l.String())
+}

internal/init_test.go

@@ -97,7 +97,7 @@ func TestAccBundleInitOnMlopsStacks(t *testing.T) {
 	require.NoError(t, err)
 	job, err := w.Jobs.GetByJobId(context.Background(), batchJobId)
 	assert.NoError(t, err)
-	assert.Equal(t, fmt.Sprintf("dev-%s-batch-inference-job", projectName), job.Settings.Name)
+	assert.Contains(t, job.Settings.Name, fmt.Sprintf("dev-%s-batch-inference-job", projectName))
 }
 
 func TestAccBundleInitHelpers(t *testing.T) {