Refactor deletes in direct deployment (#3163)

## Changes
Remove DoDelete method from IResource, add a static function per
resource.

## Why
Delete operation is special - it does not require config. In fact, it is
often run when config is gone.

On the other hand all other operations need config. 

To support both delete and non-delete operation in one class we would
need to have constant checks/asserts config != nil. To avoid this
complication, I'm taking delete out of IResource.

## Tests
Existing tests.

Author: denik

acceptance/bundle/destroy/all-resources/databricks.yml

@@ -0,0 +1,13 @@
+resources:
+  pipelines:
+    my_pipeline:
+      name: test-pipeline
+      libraries:
+        - file:
+            path: "./foo.py"
+
+  schemas:
+    my_schema:
+      name: test-schema
+      catalog_name: main
+      comment: COMMENT1

acceptance/bundle/destroy/all-resources/foo.py

@@ -0,0 +1,16 @@
+
+>>> [CLI] bundle deploy
+Uploading bundle files to /Workspace/Users/[USERNAME]/.bundle/test-bundle/default/files...
+Deploying resources...
+Updating deployment state...
+Deployment complete!
+
+>>> [CLI] bundle destroy --auto-approve
+The following resources will be deleted:
+  delete pipeline my_pipeline
+  delete schema my_schema
+
+All files and directories at the following location will be deleted: /Workspace/Users/[USERNAME]/.bundle/test-bundle/default
+
+Deleting files...
+Destroy complete!

acceptance/bundle/destroy/all-resources/output.txt

@@ -0,0 +1,2 @@
+trace $CLI bundle deploy
+trace $CLI bundle destroy --auto-approve

acceptance/bundle/destroy/all-resources/script

@@ -207,7 +207,7 @@ func (d *Deployer) Create(ctx context.Context, resource tnresources.IResource, c
 }
 
 func (d *Deployer) Recreate(ctx context.Context, oldResource tnresources.IResource, oldID string, config any) error {
-	err := oldResource.DoDelete(ctx, oldID)
+	err := tnresources.DeleteResource(ctx, d.client, d.group, oldID)
 	if err != nil {
 		return fmt.Errorf("deleting old id=%s: %w", oldID, err)
 	}
@@ -267,7 +267,7 @@ func (d *Deployer) Update(ctx context.Context, resource tnresources.IResource, o
 
 func (d *Deployer) Delete(ctx context.Context, resource tnresources.IResource, oldID string) error {
 	// TODO: recognize 404 and 403 as "deleted" and proceed to removing state
-	err := resource.DoDelete(ctx, oldID)
+	err := tnresources.DeleteResource(ctx, d.client, d.group, oldID)
 	if err != nil {
 		return fmt.Errorf("deleting id=%s: %w", oldID, err)
 	}

bundle/terranova/apply.go

@@ -54,7 +54,7 @@ func (r *ResourceApp) DoUpdate(ctx context.Context, id string) (string, error) {
 	return response.Name, nil
 }
 
-func (r *ResourceApp) DoDelete(ctx context.Context, id string) error {
+func DeleteApp(ctx context.Context, client *databricks.WorkspaceClient, id string) error {
 	// TODO: implement app deletion
 	return nil
 }

bundle/terranova/tnresources/app.go

@@ -52,12 +52,12 @@ func (r *ResourceJob) DoUpdate(ctx context.Context, id string) (string, error) {
 	return id, nil
 }
 
-func (r *ResourceJob) DoDelete(ctx context.Context, id string) error {
+func DeleteJob(ctx context.Context, client *databricks.WorkspaceClient, id string) error {
 	idInt, err := strconv.ParseInt(id, 10, 64)
 	if err != nil {
 		return err
 	}
-	err = r.client.Jobs.DeleteByJobId(ctx, idInt)
+	err = client.Jobs.DeleteByJobId(ctx, idInt)
 	if err != nil {
 		return SDKError{Method: "Jobs.DeleteByJobId", Err: err}
 	}

bundle/terranova/tnresources/job.go

@@ -49,8 +49,8 @@ func (r *ResourcePipeline) DoUpdate(ctx context.Context, id string) (string, err
 	return id, nil
 }
 
-func (r *ResourcePipeline) DoDelete(ctx context.Context, id string) error {
-	err := r.client.Pipelines.DeleteByPipelineId(ctx, id)
+func DeletePipeline(ctx context.Context, client *databricks.WorkspaceClient, id string) error {
+	err := client.Pipelines.DeleteByPipelineId(ctx, id)
 	if err != nil {
 		return SDKError{Method: "Pipelines.DeleteByPipelineId", Err: err}
 	}

bundle/terranova/tnresources/pipeline.go

@@ -11,19 +11,35 @@ import (
 	"github.com/databricks/databricks-sdk-go"
 )
 
+const (
+	_jobs      = "jobs"
+	_pipelines = "pipelines"
+	_schemas   = "schemas"
+	_apps      = "apps"
+)
+
 var supportedResources = map[string]reflect.Value{
-	"jobs":      reflect.ValueOf(NewResourceJob),
-	"pipelines": reflect.ValueOf(NewResourcePipeline),
-	"schemas":   reflect.ValueOf(NewResourceSchema),
-	"apps":      reflect.ValueOf(NewResourceApp),
+	_jobs:      reflect.ValueOf(NewResourceJob),
+	_pipelines: reflect.ValueOf(NewResourcePipeline),
+	_schemas:   reflect.ValueOf(NewResourceSchema),
+	_apps:      reflect.ValueOf(NewResourceApp),
 }
 
 // This types matches what Config() returns and should match 'config' field in the resource struct
 var supportedResourcesTypes = map[string]reflect.Type{
-	"jobs":      reflect.TypeOf(ResourceJob{}.config),
-	"pipelines": reflect.TypeOf(ResourcePipeline{}.config),
-	"schemas":   reflect.TypeOf(ResourceSchema{}.config),
-	"apps":      reflect.TypeOf(ResourceApp{}.config),
+	_jobs:      reflect.TypeOf(ResourceJob{}.config),
+	_pipelines: reflect.TypeOf(ResourcePipeline{}.config),
+	_schemas:   reflect.TypeOf(ResourceSchema{}.config),
+	_apps:      reflect.TypeOf(ResourceApp{}.config),
+}
+
+type DeleteResourceFN = func(ctx context.Context, client *databricks.WorkspaceClient, oldID string) error
+
+var deletableResources = map[string]DeleteResourceFN{
+	_jobs:      DeleteJob,
+	_pipelines: DeletePipeline,
+	_schemas:   DeleteSchema,
+	_apps:      DeleteApp,
 }
 
 type IResource interface {
@@ -34,9 +50,7 @@ type IResource interface {
 
 	// Update the resource. Returns id of the resource.
 	// Usually returns the same id as oldId but can also return a different one (e.g. schemas and volumes when certain fields are changed)
-	DoUpdate(ctx context.Context, oldId string) (string, error)
-
-	DoDelete(ctx context.Context, oldId string) error
+	DoUpdate(ctx context.Context, oldID string) (string, error)
 
 	WaitAfterCreate(ctx context.Context) error
 	WaitAfterUpdate(ctx context.Context) error
@@ -59,9 +73,7 @@ func invokeConstructor(ctor reflect.Value, client *databricks.WorkspaceClient, c
 	// Prepare the config value matching the expected type.
 	var cfgVal reflect.Value
 	if cfg == nil {
-		// Treat nil as a request for the zero value of the expected config type. This
-		// is useful for actions (like deletion) where the config is irrelevant.
-		cfgVal = reflect.Zero(expectedCfgType)
+		return nil, errors.New("internal error, config must not be nil")
 	} else {
 		suppliedVal := reflect.ValueOf(cfg)
 		if suppliedVal.Type() != expectedCfgType {
@@ -116,3 +128,11 @@ func New(client *databricks.WorkspaceClient, group, name string, config any) (IR
 
 	return result, cfgType, nil
 }
+
+func DeleteResource(ctx context.Context, client *databricks.WorkspaceClient, group, id string) error {
+	fn, ok := deletableResources[group]
+	if !ok {
+		return fmt.Errorf("cannot delete %s", group)
+	}
+	return fn(ctx, client, id)
+}

bundle/terranova/tnresources/resource.go

@@ -51,7 +51,7 @@ func (r *ResourceSchema) DoUpdate(ctx context.Context, id string) (string, error
 	return response.FullName, nil
 }
 
-func (r *ResourceSchema) DoDelete(ctx context.Context, id string) error {
+func DeleteSchema(ctx context.Context, client *databricks.WorkspaceClient, id string) error {
 	// TODO: implement schema deletion
 	return nil
 }