Add check for DB cluster available before updating (#56)

Fixes: aws-controllers-k8s/community#1107

Description of changes:
If a DB cluster is in any state other than `Available`, then an attempt to update it will return a terminal `InvalidDBClusterStateFault` error. This error will stop the cluster from reconciling any further, even though the underlying RDS DB cluster is working properly.

This PR checks that the DB cluster is in the `Available` state before running the custom update code, otherwise re-queuing it until it is.

By submitting this pull request, I confirm that my contribution is made under
the terms of the Apache 2.0 license.

Author: RedbackThomson

apis/v1alpha1/ack-generate-metadata.yaml

@@ -1,13 +1,13 @@
 ack_generate_info:
-  build_date: "2022-01-24T21:04:15Z"
-  build_hash: cccec82a27ddd880095383360df1fdc8f530842f
-  go_version: go1.17.5
+  build_date: "2022-01-31T20:23:51Z"
+  build_hash: 4ebcd703a95a2fbd71bd07130f92aa6813c1398b
+  go_version: go1.17.1
   version: v0.16.3
 api_directory_checksum: cae902b75e1b0827659c4bfe7ef9f6bb98769f5c
 api_version: v1alpha1
 aws_sdk_go_version: v1.37.10
 generator_config_info:
-  file_checksum: a40f829b03389cf1b2a003ebe2a79b97bc9d3322
+  file_checksum: e87619caa6304d2a07818296e3a6a5fd4da1e704
   original_file_name: generator.yaml
 last_modification:
   reason: API generation

apis/v1alpha1/generator.yaml

@@ -70,8 +70,6 @@ resources:
         template_path: hooks/db_cluster/sdk_create_post_set_output.go.tpl
       sdk_read_many_post_set_output:
         template_path: hooks/db_cluster/sdk_read_many_post_set_output.go.tpl
-      sdk_update_pre_build_request:
-        template_path: hooks/db_cluster/sdk_update_pre_build_request.go.tpl
       sdk_delete_pre_build_request:
         template_path: hooks/db_cluster/sdk_delete_pre_build_request.go.tpl
     exceptions:

generator.yaml

@@ -70,8 +70,6 @@ resources:
         template_path: hooks/db_cluster/sdk_create_post_set_output.go.tpl
       sdk_read_many_post_set_output:
         template_path: hooks/db_cluster/sdk_read_many_post_set_output.go.tpl
-      sdk_update_pre_build_request:
-        template_path: hooks/db_cluster/sdk_update_pre_build_request.go.tpl
       sdk_delete_pre_build_request:
         template_path: hooks/db_cluster/sdk_delete_pre_build_request.go.tpl
     exceptions:

pkg/resource/db_cluster/custom_update.go

@@ -50,6 +50,12 @@ func (rm *resourceManager) customUpdate(
 		ackcondition.SetSynced(desired, corev1.ConditionFalse, &msg, nil)
 		return desired, requeueWaitUntilCanModify(latest)
 	}
+	if !clusterAvailable(latest) {
+		msg := "DB cluster is not available for modification in '" +
+			*latest.ko.Status.Status + "' status"
+		ackcondition.SetSynced(desired, corev1.ConditionFalse, &msg, nil)
+		return desired, requeueWaitUntilCanModify(latest)
+	}
 	if clusterHasTerminalStatus(latest) {
 		msg := "DB cluster is in '" + *latest.ko.Status.Status + "' status"
 		ackcondition.SetTerminal(desired, corev1.ConditionTrue, &msg, nil)