Sort tasks by task_key before generating the Terraform configuration

bundle/deploy/terraform/convert.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"sort"
 
 	"github.com/databricks/cli/bundle/config"
 	"github.com/databricks/cli/bundle/config/resources"
@@ -82,6 +83,10 @@ func BundleToTerraform(config *config.Root) *schema.Root {
 		conv(src, &dst)
 
 		if src.JobSettings != nil {
+			sort.Slice(src.JobSettings.Tasks, func(i, j int) bool {
+				return src.JobSettings.Tasks[i].TaskKey < src.JobSettings.Tasks[j].TaskKey
+			})
+
 			for _, v := range src.Tasks {
 				var t schema.ResourceJobTask
 				conv(v, &t)

bundle/deploy/terraform/tfdyn/convert_job.go

@@ -3,6 +3,7 @@ package tfdyn
 import (
 	"context"
 	"fmt"
+	"sort"
 
 	"github.com/databricks/cli/bundle/internal/tf/schema"
 	"github.com/databricks/cli/libs/dyn"
@@ -19,8 +20,36 @@ func convertJobResource(ctx context.Context, vin dyn.Value) (dyn.Value, error) {
 		log.Debugf(ctx, "job normalization diagnostic: %s", diag.Summary)
 	}
 
+	// Sort the tasks of each job in the bundle by task key. Sorting
+	// the task keys ensures that the diff computed by terraform is correct and avoids
+	// recreates. For more details see the NOTE at
+	// https://registry.terraform.io/providers/databricks/databricks/latest/docs/resources/job#example-usage
+	// and https://github.com/databricks/terraform-provider-databricks/issues/4011
+	vout := vin
+	var err error
+	tasks, ok := vin.Get("tasks").AsSequence()
+	if ok {
+		sort.Slice(tasks, func(i, j int) bool {
+			tk1, ok := tasks[i].Get("task_key").AsString()
+			if !ok {
+				return true
+			}
+			tk2, ok := tasks[j].Get("task_key").AsString()
+			if !ok {
+				return false
+			}
+			return tk1 < tk2
+		})
+		vout, err = dyn.Map(vin, "tasks", func(_ dyn.Path, _ dyn.Value) (dyn.Value, error) {
+			return dyn.V(tasks), nil
+		})
+		if err != nil {
+			return dyn.InvalidValue, err
+		}
+	}
+
 	// Modify top-level keys.
-	vout, err := renameKeys(vin, map[string]string{
+	vout, err = renameKeys(vout, map[string]string{
 		"tasks":        "task",
 		"job_clusters": "job_cluster",
 		"parameters":   "parameter",

bundle/deploy/terraform/tfdyn/convert_job_test.go

@@ -42,8 +42,8 @@ func TestConvertJob(t *testing.T) {
 			},
 			Tasks: []jobs.Task{
 				{
-					TaskKey:       "task_key",
-					JobClusterKey: "job_cluster_key",
+					TaskKey:       "task_key_b",
+					JobClusterKey: "job_cluster_key_b",
 					Libraries: []compute.Library{
 						{
 							Pypi: &compute.PythonPyPiLibrary{
@@ -55,6 +55,17 @@ func TestConvertJob(t *testing.T) {
 						},
 					},
 				},
+				{
+					TaskKey:       "task_key_a",
+					JobClusterKey: "job_cluster_key_a",
+				},
+				{
+					TaskKey:       "task_key_c",
+					JobClusterKey: "job_cluster_key_c",
+				},
+				{
+					Description: "missing task key 😱",
+				},
 			},
 		},
 		Permissions: []resources.Permission{
@@ -100,8 +111,15 @@ func TestConvertJob(t *testing.T) {
 		},
 		"task": []any{
 			map[string]any{
-				"task_key":        "task_key",
-				"job_cluster_key": "job_cluster_key",
+				"description": "missing task key 😱",
+			},
+			map[string]any{
+				"task_key":        "task_key_a",
+				"job_cluster_key": "job_cluster_key_a",
+			},
+			map[string]any{
+				"task_key":        "task_key_b",
+				"job_cluster_key": "job_cluster_key_b",
 				"library": []any{
 					map[string]any{
 						"pypi": map[string]any{
@@ -113,6 +131,10 @@ func TestConvertJob(t *testing.T) {
 					},
 				},
 			},
+			map[string]any{
+				"task_key":        "task_key_c",
+				"job_cluster_key": "job_cluster_key_c",
+			},
 		},
 	}, out.Job["my_job"])