Support serverless mode in default-python template (explicit prompt) (#2377)

## Changes

- Add 'serverless' prompt to default-python template (default is
currently set to "no").
- This is a simplified version of
https://github.com/databricks/cli/pull/2348 with 'auto' functionality
removed.

## Tests
- Split default-python into default-python/classic,
default-python/serverless, default-python/serverless-customcatalog.
- Manually check that "bundle init default-python" with serverless=yes
can be deployed and run on dogfood and test env.

acceptance/bundle/templates/default-python/classic/input.json

@@ -2,5 +2,6 @@
     "project_name": "my_default_python",
     "include_notebook": "yes",
     "include_dlt": "yes",
-    "include_python": "yes"
+    "include_python": "yes",
+    "serverless": "no"
 }

acceptance/bundle/templates/default-python/classic/out.compare-vs-serverless.diff

@@ -0,0 +1,54 @@
+--- [TESTROOT]/bundle/templates/default-python/classic/../serverless/output/my_default_python/resources/my_default_python.job.yml
++++ output/my_default_python/resources/my_default_python.job.yml
+@@ -17,4 +17,5 @@
+       tasks:
+         - task_key: notebook_task
++          job_cluster_key: job_cluster
+           notebook_task:
+             notebook_path: ../src/notebook.ipynb
+@@ -29,17 +30,21 @@
+           depends_on:
+             - task_key: refresh_pipeline
+-          environment_key: default
++          job_cluster_key: job_cluster
+           python_wheel_task:
+             package_name: my_default_python
+             entry_point: main
++          libraries:
++            # By default we just include the .whl file generated for the my_default_python package.
++            # See https://docs.databricks.com/dev-tools/bundles/library-dependencies.html
++            # for more information on how to add other libraries.
++            - whl: ../dist/*.whl
+ 
+-      # A list of task execution environment specifications that can be referenced by tasks of this job.
+-      environments:
+-        - environment_key: default
+-
+-          # Full documentation of this spec can be found at:
+-          # https://docs.databricks.com/api/workspace/jobs/create#environments-spec
+-          spec:
+-            client: "1"
+-            dependencies:
+-              - ../dist/*.whl
++      job_clusters:
++        - job_cluster_key: job_cluster
++          new_cluster:
++            spark_version: 15.4.x-scala2.12
++            node_type_id: i3.xlarge
++            data_security_mode: SINGLE_USER
++            autoscale:
++                min_workers: 1
++                max_workers: 4
+--- [TESTROOT]/bundle/templates/default-python/classic/../serverless/output/my_default_python/resources/my_default_python.pipeline.yml
++++ output/my_default_python/resources/my_default_python.pipeline.yml
+@@ -4,8 +4,7 @@
+     my_default_python_pipeline:
+       name: my_default_python_pipeline
+-      ## Catalog is required for serverless compute
+-      catalog: main
++      ## Specify the 'catalog' field to configure this pipeline to make use of Unity Catalog:
++      # catalog: catalog_name
+       target: my_default_python_${bundle.target}
+-      serverless: true
+       libraries:
+         - notebook:

acceptance/bundle/templates/default-python/classic/script

@@ -0,0 +1,15 @@
+trace $CLI bundle init default-python --config-file ./input.json --output-dir output
+
+cd output/my_default_python
+trace $CLI bundle validate -t dev
+trace $CLI bundle validate -t prod
+
+# Do not affect this repository's git behaviour #2318
+mv .gitignore out.gitignore
+
+cd ../../
+
+# Calculate the difference from the serverless template
+diff.py $TESTDIR/../serverless/output output/ > out.compare-vs-serverless.diff
+
+rm -fr output

acceptance/bundle/templates/default-python/serverless-customcatalog/output.txt

@@ -0,0 +1,22 @@
+
+>>> [CLI] bundle init default-python --config-file [TESTROOT]/bundle/templates/default-python/serverless-customcatalog/../serverless/input.json --output-dir output
+
+Welcome to the default Python template for Databricks Asset Bundles!
+Workspace to use (auto-detected, edit in 'my_default_python/databricks.yml'): [DATABRICKS_URL]
+
+✨ Your new project has been created in the 'my_default_python' directory!
+
+Please refer to the README.md file for "getting started" instructions.
+See also the documentation at https://docs.databricks.com/dev-tools/bundles/index.html.
+
+>>> diff.py [TESTROOT]/bundle/templates/default-python/serverless-customcatalog/../serverless/output output/
+--- [TESTROOT]/bundle/templates/default-python/serverless-customcatalog/../serverless/output/my_default_python/resources/my_default_python.pipeline.yml
++++ output/my_default_python/resources/my_default_python.pipeline.yml
+@@ -4,6 +4,5 @@
+     my_default_python_pipeline:
+       name: my_default_python_pipeline
+-      ## Catalog is required for serverless compute
+-      catalog: main
++      catalog: customcatalog
+       target: my_default_python_${bundle.target}
+       serverless: true

acceptance/bundle/templates/default-python/serverless-customcatalog/script

@@ -0,0 +1,4 @@
+trace $CLI bundle init default-python --config-file $TESTDIR/../serverless/input.json --output-dir output
+mv output/my_default_python/.gitignore output/my_default_python/out.gitignore
+trace diff.py $TESTDIR/../serverless/output output/
+rm -fr output

acceptance/bundle/templates/default-python/serverless-customcatalog/test.toml

@@ -0,0 +1,8 @@
+[[Server]]
+Pattern = "GET /api/2.1/unity-catalog/current-metastore-assignment"
+Response.Body = '{"default_catalog_name": "customcatalog"}'
+
+[[Repls]]
+# windows fix
+Old = '\\'
+New = '/'

acceptance/bundle/templates/default-python/serverless/input.json

@@ -0,0 +1,7 @@
+{
+    "project_name": "my_default_python",
+    "include_notebook": "yes",
+    "include_dlt": "yes",
+    "include_python": "yes",
+    "serverless": "yes"
+}

acceptance/bundle/templates/default-python/serverless/output.txt

@@ -0,0 +1,30 @@
+
+>>> [CLI] bundle init default-python --config-file ./input.json --output-dir output
+
+Welcome to the default Python template for Databricks Asset Bundles!
+Workspace to use (auto-detected, edit in 'my_default_python/databricks.yml'): [DATABRICKS_URL]
+
+✨ Your new project has been created in the 'my_default_python' directory!
+
+Please refer to the README.md file for "getting started" instructions.
+See also the documentation at https://docs.databricks.com/dev-tools/bundles/index.html.
+
+>>> [CLI] bundle validate -t dev
+Name: my_default_python
+Target: dev
+Workspace:
+  Host: [DATABRICKS_URL]
+  User: [USERNAME]
+  Path: /Workspace/Users/[USERNAME]/.bundle/my_default_python/dev
+
+Validation OK!
+
+>>> [CLI] bundle validate -t prod
+Name: my_default_python
+Target: prod
+Workspace:
+  Host: [DATABRICKS_URL]
+  User: [USERNAME]
+  Path: /Workspace/Users/[USERNAME]/.bundle/my_default_python/prod
+
+Validation OK!

acceptance/bundle/templates/default-python/serverless/output/my_default_python/resources/my_default_python.job.yml

@@ -16,7 +16,6 @@ resources:
 
       tasks:
         - task_key: notebook_task
-          job_cluster_key: job_cluster
           notebook_task:
             notebook_path: ../src/notebook.ipynb
         
@@ -29,22 +28,18 @@ resources:
         - task_key: main_task
           depends_on:
             - task_key: refresh_pipeline
-          job_cluster_key: job_cluster
+          environment_key: default
           python_wheel_task:
             package_name: my_default_python
             entry_point: main
-          libraries:
-            # By default we just include the .whl file generated for the my_default_python package.
-            # See https://docs.databricks.com/dev-tools/bundles/library-dependencies.html
-            # for more information on how to add other libraries.
-            - whl: ../dist/*.whl
 
-      job_clusters:
-        - job_cluster_key: job_cluster
-          new_cluster:
-            spark_version: 15.4.x-scala2.12
-            node_type_id: i3.xlarge
-            data_security_mode: SINGLE_USER
-            autoscale:
-                min_workers: 1
-                max_workers: 4
+      # A list of task execution environment specifications that can be referenced by tasks of this job.
+      environments:
+        - environment_key: default
+
+          # Full documentation of this spec can be found at:
+          # https://docs.databricks.com/api/workspace/jobs/create#environments-spec
+          spec:
+            client: "1"
+            dependencies:
+              - ../dist/*.whl

acceptance/bundle/templates/default-python/serverless/output/my_default_python/resources/my_default_python.pipeline.yml

@@ -3,8 +3,10 @@ resources:
   pipelines:
     my_default_python_pipeline:
       name: my_default_python_pipeline
+      ## Catalog is required for serverless compute
       catalog: main
       target: my_default_python_${bundle.target}
+      serverless: true
       libraries:
         - notebook:
             path: ../src/dlt_pipeline.ipynb

acceptance/server_test.go

@@ -20,6 +20,12 @@ var testUser = iam.User{
 	UserName: "tester@databricks.com",
 }
 
+var testMetastore = catalog.MetastoreAssignment{
+	DefaultCatalogName: "hive_metastore",
+	MetastoreId:        "120efa64-9b68-46ba-be38-f319458430d2",
+	WorkspaceId:        470123456789500,
+}
+
 func AddHandlers(server *testserver.Server) {
 	server.Handle("GET", "/api/2.0/policies/clusters/list", func(req testserver.Request) any {
 		return compute.ListPoliciesResponse{
@@ -106,9 +112,7 @@ func AddHandlers(server *testserver.Server) {
 	})
 
 	server.Handle("GET", "/api/2.1/unity-catalog/current-metastore-assignment", func(req testserver.Request) any {
-		return catalog.MetastoreAssignment{
-			DefaultCatalogName: "main",
-		}
+		return testMetastore
 	})
 
 	server.Handle("GET", "/api/2.0/permissions/directories/{objectId}", func(req testserver.Request) any {

libs/template/renderer_test.go

@@ -116,14 +116,17 @@ func TestBuiltinPythonTemplateValid(t *testing.T) {
 		for _, includeDlt := range options {
 			for _, includePython := range options {
 				for _, isServicePrincipal := range []bool{true, false} {
-					config := map[string]any{
-						"project_name":     "my_project",
-						"include_notebook": includeNotebook,
-						"include_dlt":      includeDlt,
-						"include_python":   includePython,
+					for _, serverless := range options {
+						config := map[string]any{
+							"project_name":     "my_project",
+							"include_notebook": includeNotebook,
+							"include_dlt":      includeDlt,
+							"include_python":   includePython,
+							"serverless":       serverless,
+						}
+						tempDir := t.TempDir()
+						assertBuiltinTemplateValid(t, "default-python", config, "dev", isServicePrincipal, build, tempDir)
 					}
-					tempDir := t.TempDir()
-					assertBuiltinTemplateValid(t, "default-python", config, "dev", isServicePrincipal, build, tempDir)
 				}
 			}
 		}
@@ -135,6 +138,7 @@ func TestBuiltinPythonTemplateValid(t *testing.T) {
 		"include_notebook": "yes",
 		"include_dlt":      "yes",
 		"include_python":   "yes",
+		"serverless":       "yes",
 	}
 	isServicePrincipal = false
 	build = true

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

@@ -29,6 +29,13 @@
             "enum": ["yes", "no"],
             "description": "Include a stub (sample) Python package in '{{.project_name}}{{path_separator}}src'",
             "order": 4
+        },
+        "serverless": {
+            "type": "string",
+            "default": "no",
+            "enum": ["yes", "no"],
+            "description": "Use serverless compute",
+            "order": 5
         }
     },
     "success_message": "Workspace to use (auto-detected, edit in '{{.project_name}}/databricks.yml'): {{workspace_host}}\n\n✨ Your new project has been created in the '{{.project_name}}' directory!\n\nPlease refer to the README.md file for \"getting started\" instructions.\nSee also the documentation at https://docs.databricks.com/dev-tools/bundles/index.html."

libs/template/templates/default-python/template/{{.project_name}}/resources/{{.project_name}}.job.yml.tmpl

@@ -4,6 +4,7 @@
 {{if and (eq .include_dlt "yes") (and (eq .include_notebook "no") (eq .include_python "no")) -}}
 # This job runs {{.project_name}}_pipeline on a schedule.
 {{end -}}
+{{$with_serverless := (eq .serverless "yes") -}}
 
 resources:
   jobs:
@@ -29,7 +30,8 @@ resources:
       tasks:
         {{- if eq .include_notebook "yes" }}
         - task_key: notebook_task
-          job_cluster_key: job_cluster
+        {{- if not $with_serverless}}
+          job_cluster_key: job_cluster{{end}}
           notebook_task:
             notebook_path: ../src/notebook.ipynb
         {{end -}}
@@ -52,18 +54,34 @@ resources:
           depends_on:
             - task_key: notebook_task
           {{end}}
-          job_cluster_key: job_cluster
+          {{- if $with_serverless }}
+          environment_key: default
+          {{- else }}
+          job_cluster_key: job_cluster{{end}}
           python_wheel_task:
             package_name: {{.project_name}}
             entry_point: main
+          {{- if not $with_serverless }}
           libraries:
             # By default we just include the .whl file generated for the {{.project_name}} package.
             # See https://docs.databricks.com/dev-tools/bundles/library-dependencies.html
             # for more information on how to add other libraries.
             - whl: ../dist/*.whl
+{{- end -}}
+{{else}}
+{{- end}}
+{{if $with_serverless}}
+      # A list of task execution environment specifications that can be referenced by tasks of this job.
+      environments:
+        - environment_key: default
 
-      {{else}}
-      {{end -}}
+          # Full documentation of this spec can be found at:
+          # https://docs.databricks.com/api/workspace/jobs/create#environments-spec
+          spec:
+            client: "1"
+            dependencies:
+              - ../dist/*.whl
+{{ else }}
       job_clusters:
         - job_cluster_key: job_cluster
           new_cluster:
@@ -73,3 +91,4 @@ resources:
             autoscale:
                 min_workers: 1
                 max_workers: 4
+{{end -}}

libs/template/templates/default-python/template/{{.project_name}}/resources/{{.project_name}}.pipeline.yml.tmpl

@@ -1,15 +1,22 @@
+{{$with_serverless := (eq .serverless "yes") -}}
 # The main pipeline for {{.project_name}}
 resources:
   pipelines:
     {{.project_name}}_pipeline:
       name: {{.project_name}}_pipeline
       {{- if or (eq default_catalog "") (eq default_catalog "hive_metastore")}}
+      {{- if $with_serverless }}
+      ## Catalog is required for serverless compute
+      catalog: main{{else}}
       ## Specify the 'catalog' field to configure this pipeline to make use of Unity Catalog:
-      # catalog: catalog_name
+      # catalog: catalog_name{{end}}
       {{- else}}
       catalog: {{default_catalog}}
       {{- end}}
       target: {{.project_name}}_${bundle.target}
+      {{- if $with_serverless }}
+      serverless: true
+      {{- end}}
       libraries:
         - notebook:
             path: ../src/dlt_pipeline.ipynb