DPE-2957 async replication (#375)

* import from k8s and owned library

* standardized address

* method in lib

* to be removed workaround before confirming proper behavior

* addressing PR comments

* scale-in locks write to global primary

* second batch of PR comments adressing

* fence/unfence actions

* fix for single unit replica cluster

* workaround: secrets in relation data

* append correct host when syncing users and fix option setup

* unit test fixes

* refactor for code sharing

* port from k8s and test fixes

* fix for localhost only root

* address pr feedback

* (wip) integration test

* tweak test execution

* missing parameter

* adding test coverage

* increasing coverage

* more coverage #2

* increase coverage #3

* pr comments

* increase coverage #4

* bump lib version since previous version merged on k8s

* better messaging and rollback hack on data_secrets

Author: paulomach

actions.yaml

@@ -3,6 +3,12 @@
 
 get-cluster-status:
   description: Get cluster status information
+  params:
+    cluster-set:
+      type: boolean
+      default: False
+      description: Whether to fetch the cluster or cluster-set status.
+        Possible values are False (default) or True.
 
 get-password:
   description: Fetch the system user's password, which is used by charm.
@@ -53,3 +59,53 @@ restore:
 pre-upgrade-check:
   description: Run necessary pre-upgrade checks and preparations before executing a charm refresh.
 
+promote-standby-cluster:
+  description: |
+    Promotes this cluster to become the leader in the cluster-set. Used for safe switchover or failover.
+    Must be run against the charm leader unit of a standby cluster.
+  params:
+    cluster-set-name:
+      type: string
+      description: |
+        The name of the cluster-set. Mandatory option, used for confirmation.
+    force:
+      type: boolean
+      default: False
+      description: |
+        Use force when previous primary is unreachable (failover). Will invalidate previous
+        primary.
+
+recreate-cluster:
+  description: |
+    Recreates cluster on one or more standalone units that were previously part of a standby cluster.
+
+    When a standby cluster is removed from an async replication relation, the cluster will be dissolved and
+    each unit will be kept in blocked status. Recreating the cluster allows to rejoin the async replication
+    relation, or usage as a standalone cluster.
+
+fence-writes:
+  description: |
+    Stops write traffic to a primary cluster of a ClusterSet.
+  params:
+    cluster-set-name:
+      type: string
+      description: |
+        The name of the cluster-set. Mandatory option, used for confirmation.
+
+unfence-writes:
+  description: |
+    Resumes write traffic to a primary cluster of a ClusterSet.
+  params:
+    cluster-set-name:
+      type: string
+      description: |
+        The name of the cluster-set. Mandatory option, used for confirmation.
+
+rejoin-cluster:
+  description: |
+    Rejoins an invalidated cluster to the cluster-set, after a previous failover or switchover.
+  params:
+    cluster-name:
+      type: string
+      description: |
+        The name of the cluster to be rejoined.

config.yaml

@@ -3,7 +3,12 @@
 
 options:
   cluster-name:
-    description: "Optional - Name of the MySQL InnoDB cluster"
+    description: "Optional - Name of the MySQL InnoDB cluster, set once at deployment"
+    type: "string"
+  cluster-set-name:
+    description: |
+      Optional - Name for async replication cluster set, set once at deployment.
+      On `recreate-clster` action call, the cluster set name will be re-generated automatically.
     type: "string"
   profile:
     description: |