fixing datasource schema for tanzu kubernetes clusters and adding generic helper

.gitignore

@@ -1,5 +1,5 @@
 # Ignore any built binaries.
-terraform-provider-tanzu-mission-control
+terraform-provider-tanzu-mission-control*
 terraform-provider-tanzu-mission-control.exe
 
 # Ignore distribution directories.
@@ -14,3 +14,4 @@ dist/
 
 # Ignore macOS desktop services store files.
 **/.DS_Store
+

internal/helper/helper.go

@@ -227,3 +227,77 @@
 
 	return keys
 }
+
+// DatasourceSchemaFromResourceSchema is a recursive func that
+// converts an existing Resource schema to a Datasource schema.
+// All schema elements are copied, but certain attributes are ignored or changed:
+// - all attributes have Computed = true
+// - all attributes have ForceNew, Required = false
+// - Validation funcs and attributes (e.g. MaxItems) are not copied
+func DatasourceSchemaFromResourceSchema(rs map[string]*schema.Schema) map[string]*schema.Schema {
+	ds := make(map[string]*schema.Schema, len(rs))
+	for k, v := range rs {
+		dv := &schema.Schema{
+			Computed:    true,
+			ForceNew:    false,
+			Required:    false,
+			Description: v.Description,
+			Type:        v.Type,
+		}
+
+		switch v.Type {
+		case schema.TypeSet:
+			dv.Set = v.Set
+			fallthrough
+		case schema.TypeList:
+			// List & Set types are generally used for 2 cases:
+			// - a list/set of simple primitive values (e.g. list of strings)
+			// - a sub resource
+			if elem, ok := v.Elem.(*schema.Resource); ok {
+				// handle the case where the Element is a sub-resource
+				dv.Elem = &schema.Resource{
+					Schema: DatasourceSchemaFromResourceSchema(elem.Schema),
+				}
+			} else {
+				// handle simple primitive case
+				dv.Elem = v.Elem
+			}
+
+		default:
+			// Elem of all other types are copied as-is
+			dv.Elem = v.Elem
+
+		}
+		ds[k] = dv
+
+	}
+	return ds
+}
+
+// fixDatasourceSchemaFlags is a convenience func that toggles the Computed,
+// Optional + Required flags on a schema element. This is useful when the schema
+// has been generated (using `DatasourceSchemaFromResourceSchema` above for
+// example) and therefore the attribute flags were not set appropriately when
+// first added to the schema definition. Currently only supports top-level
+// schema elements.
+func FixDatasourceSchemaFlags(schema map[string]*schema.Schema, required bool, keys ...string) {
+	for _, v := range keys {
+		schema[v].Computed = false
+		schema[v].Optional = !required
+		schema[v].Required = required
+	}
+}
+
+func AddRequiredFieldsToSchema(schema map[string]*schema.Schema, keys ...string) {
+	FixDatasourceSchemaFlags(schema, true, keys...)
+}
+
+func AddOptionalFieldsToSchema(schema map[string]*schema.Schema, keys ...string) {
+	FixDatasourceSchemaFlags(schema, false, keys...)
+}
+
+func DeleteFieldsFromSchema(schema map[string]*schema.Schema, keys ...string) {
+	for _, key := range keys {
+		delete(schema, key)
+	}
+}

internal/resources/tanzukubernetescluster/data_source.go

@@ -17,12 +17,18 @@
 	tanzukubernetesclustermodels "github.com/vmware/terraform-provider-tanzu-mission-control/internal/models/tanzukubernetescluster"
 )
 
 func DataSourceTanzuKubernetesCluster() *schema.Resource {
+
+	dsSchema := helper.DatasourceSchemaFromResourceSchema(tanzuKubernetesClusterSchema)
+
+	// Set 'Required' schema elements
+	helper.AddRequiredFieldsToSchema(dsSchema, "name", "management_cluster_name", "provisioner_name")
+
 	return &schema.Resource{
 		ReadContext: func(ctx context.Context, d *schema.ResourceData, m interface{}) diag.Diagnostics {
 			return dataSourceTanzuKubernetesClusterRead(helper.GetContextWithCaller(ctx, helper.DataRead), d, m)
 		},
-		Schema: tanzuKubernetesClusterSchema,
+		Schema: dsSchema,
 	}
 }
 

main.go

@@ -24,7 +24,7 @@ func main() {
 
 	if debugMode {
 		opts.Debug = debugMode
-		opts.ProviderAddr = "vmware/dev/tanzu-mission-control"
+		opts.ProviderAddr = "vmware/tanzu-mission-control"
 	}
 
 	plugin.Serve(opts)