Skip lib refresh for clusters with no libs (#1024)

Allowed managing of libraries on `databricks_cluster` outside of Terraform state for resources without any `library` configuration blocks.

**Behavior changes**

* Whenever library is installed on `databricks_cluster` without any [`library` configuration blocks](https://registry.terraform.io/providers/databrickslabs/databricks/latest/docs/resources/cluster#library-configuration-block), it won't be removed anymore.

Author: nfx

CHANGELOG.md

@@ -3,6 +3,11 @@
 ## 0.4.4
 
 * Added support for [running provider in a debug mode](https://www.terraform.io/plugin/sdkv2/debugging#running-terraform-with-a-provider-in-debug-mode) from Visual Studio Code through `Debug Provider` run configuration in order to troubleshoot more complicated issues.
+* Allowed managing of libraries on `databricks_cluster` outside of Terraform state for resources without any `library` configuration blocks. This should simplify PaaS-like CI/CD workflows.
+
+**Behavior changes**
+
+* Whenever library is installed on `databricks_cluster` without any [`library` configuration blocks](https://registry.terraform.io/providers/databrickslabs/databricks/latest/docs/resources/cluster#library-configuration-block), it won't be removed anymore.
 
 ## 0.4.3
 

clusters/resource_cluster.go

@@ -195,6 +195,11 @@ func resourceClusterRead(ctx context.Context, d *schema.ResourceData, c *common.
 		return err
 	}
 	d.Set("url", c.FormatURL("#setting/clusters/", d.Id(), "/configuration"))
+	if d.Get("library.#").(int) == 0 {
+		// don't add externally added libraries, if config has no `library {}` blocks
+		// TODO: check if it still works fine with importing. Perhaps os.Setenv will do the trick
+		return nil
+	}
 	librariesAPI := libraries.NewLibrariesAPI(ctx, c)
 	libsClusterStatus, err := librariesAPI.WaitForLibrariesInstalled(libraries.Wait{
 		ClusterID: d.Id(),
@@ -269,7 +274,11 @@ func resourceClusterUpdate(ctx context.Context, d *schema.ResourceData, c *commo
 			return err
 		}
 	}
-
+	oldNumLibs, newNumLibs := d.GetChange("library.#")
+	if oldNumLibs == newNumLibs && oldNumLibs.(int) == 0 {
+		// don't add externally added libraries, if config has no `library {}` blocks
+		return nil
+	}
 	var libraryList libraries.ClusterLibraryList
 	common.DataToStructPointer(d, clusterSchema, &libraryList)
 	librariesAPI := libraries.NewLibrariesAPI(ctx, c)

clusters/resource_cluster_test.go

@@ -419,22 +419,6 @@ func TestResourceClusterRead(t *testing.T) {
 					TotalCount: 0,
 				},
 			},
-			{
-				Method:   "GET",
-				Resource: "/api/2.0/libraries/cluster-status?cluster_id=abc",
-				Response: libraries.ClusterLibraryStatuses{
-					LibraryStatuses: []libraries.LibraryStatus{
-						{
-							Library: &libraries.Library{
-								Pypi: &libraries.PyPi{
-									Package: "requests",
-								},
-							},
-							Status: "INSTALLED",
-						},
-					},
-				},
-			},
 		},
 		Resource: ResourceCluster(),
 		Read:     true,
@@ -447,7 +431,6 @@ func TestResourceClusterRead(t *testing.T) {
 	assert.Equal(t, "Shared Autoscaling", d.Get("cluster_name"))
 	assert.Equal(t, "i3.xlarge", d.Get("node_type_id"))
 	assert.Equal(t, 4, d.Get("autoscale.0.max_workers"))
-	assert.Equal(t, "requests", d.Get("library.2047590238.pypi.0.package"))
 	assert.Equal(t, "RUNNING", d.Get("state"))
 	assert.Equal(t, false, d.Get("is_pinned"))