added role/From impl for single zookeeper role plus parsing test

Author: adwk67

rust/operator-binary/src/crd/mod.rs

@@ -31,6 +31,7 @@ use stackable_operator::{
             kubernetes::{
                 ConfigMapName, ListenerClassName, ListenerName, NamespaceName, ServiceName,
             },
+            operator::RoleName,
         },
     },
     versioned::versioned,
@@ -335,6 +336,18 @@ pub enum ZookeeperRole {
     Server,
 }
 
+impl From<ZookeeperRole> for RoleName {
+    fn from(value: ZookeeperRole) -> Self {
+        RoleName::from_str(&value.to_string()).expect("a ZookeeperRole is a valid role name")
+    }
+}
+
+impl From<&ZookeeperRole> for RoleName {
+    fn from(value: &ZookeeperRole) -> Self {
+        RoleName::from_str(&value.to_string()).expect("a ZookeeperRole is a valid role name")
+    }
+}
+
 /// Reference to a single `Pod` that is a component of a [`v1alpha1::ZookeeperCluster`]
 ///
 /// Used for service discovery.

rust/operator-binary/src/zk_controller/build/resource/discovery.rs

@@ -15,7 +15,7 @@ use stackable_operator::{
 };
 
 use crate::{
-    crd::{ZOOKEEPER_SERVER_PORT_NAME, security::ZookeeperSecurity},
+    crd::{ZOOKEEPER_SERVER_PORT_NAME, ZookeeperRole, security::ZookeeperSecurity},
     zk_controller::{
         build::PLACEHOLDER_DISCOVERY_ROLE_GROUP,
         validate::{ValidatedCluster, operator_name, product_name},
@@ -150,7 +150,7 @@ fn build_discovery_configmap_for_owner(
                     product_version,
                     &operator_name(),
                     &controller_name,
-                    &ValidatedCluster::role_name(),
+                    &ZookeeperRole::Server.into(),
                     &role_group_name,
                 ))
                 .build(),

rust/operator-binary/src/zk_controller/build/resource/pdb.rs

@@ -24,7 +24,7 @@ pub fn build_pdb(
     let pdb = pod_disruption_budget_builder_with_role(
         cluster,
         &product_name(),
-        &ValidatedCluster::role_name(),
+        &ZookeeperRole::Server.into(),
         &operator_name(),
         &controller_name(),
     )

rust/operator-binary/src/zk_controller/validate.rs

@@ -295,20 +295,14 @@ impl ValidatedCluster {
         }
     }
 
-    /// The one ZooKeeper role name (`server`).
-    pub fn role_name() -> RoleName {
-        RoleName::from_str(&ZookeeperRole::Server.to_string())
-            .expect("the server role name is a valid role name")
-    }
-
     /// Type-safe names for the resources of a given role group.
     pub(crate) fn role_group_resource_names(
         &self,
         role_group_name: &RoleGroupName,
     ) -> ResourceNames {
         ResourceNames {
             cluster_name: self.name.clone(),
-            role_name: Self::role_name(),
+            role_name: ZookeeperRole::Server.into(),
             role_group_name: role_group_name.clone(),
         }
     }
@@ -323,7 +317,7 @@ impl ValidatedCluster {
     }
 
     pub fn recommended_labels(&self, role_group_name: &RoleGroupName) -> Labels {
-        self.recommended_labels_for(&Self::role_name(), role_group_name)
+        self.recommended_labels_for(&ZookeeperRole::Server.into(), role_group_name)
     }
 
     pub fn recommended_labels_for(
@@ -337,7 +331,7 @@ impl ValidatedCluster {
     pub fn unversioned_recommended_labels(&self, role_group_name: &RoleGroupName) -> Labels {
         self.recommended_labels_with(
             &UNVERSIONED_PRODUCT_VERSION,
-            &Self::role_name(),
+            &ZookeeperRole::Server.into(),
             role_group_name,
         )
     }
@@ -361,7 +355,12 @@ impl ValidatedCluster {
 
     /// Selector labels matching the pods of a role group.
     pub fn role_group_selector(&self, role_group_name: &RoleGroupName) -> Labels {
-        role_group_selector(self, &product_name(), &Self::role_name(), role_group_name)
+        role_group_selector(
+            self,
+            &product_name(),
+            &ZookeeperRole::Server.into(),
+            role_group_name,
+        )
     }
 
     /// Returns an [`ObjectMetaBuilder`] pre-filled with the namespace, an owner reference back to
@@ -749,4 +748,14 @@ mod tests {
             Some(Quantity("3Gi".to_owned()))
         );
     }
+
+    /// Locks the invariant behind the `expect` in the `From<ZookeeperRole> for RoleName` impls:
+    /// every `ZookeeperRole` variant (present and future) must serialise to a valid `RoleName`.
+    #[test]
+    fn every_zookeeper_role_serialises_to_a_valid_role_name() {
+        for role in ZookeeperRole::iter() {
+            let _: RoleName = (&role).into();
+            let _: RoleName = role.into();
+        }
+    }
 }