Revert to preferring IP addresses for Node listeners by default

CHANGELOG.md

@@ -6,14 +6,14 @@ All notable changes to this project will be documented in this file.
 
 ### Added
 
-- `Listener.status.addresses` can now be configured to prefer either IP addresses or DNS hostnames ([#233]).
+- `Listener.status.addresses` can now be configured to prefer either IP addresses or DNS hostnames ([#233], [#244]).
 - The operator can now run on Kubernetes clusters using a non-default cluster domain.
   Use the env var `KUBERNETES_CLUSTER_DOMAIN` or the operator Helm chart property `kubernetesClusterDomain` to set a non-default cluster domain ([#237]).
 
 ### Changed
 
 - `Listener.status.addresses` for NodePort listeners now includes replicas that are currently unavailable ([#231]).
-- `Listener.status.addresses` now defaults to DNS hostnames for all service types (previously NodePort and ClusterIP would prefer IP addresses, [#233]).
+- BREAKING: `Listener.status.addresses` now defaults to DNS hostnames for ClusterIP services, rather than IP addresses ([#233], [#244]).
 - Stale Listener subobjects will now be deleted ([#232]).
 - Tagged Listener Services with the SDP labels ([#232]).
 
@@ -30,6 +30,7 @@ All notable changes to this project will be documented in this file.
 [#234]: https://github.com/stackabletech/listener-operator/pull/234
 [#237]: https://github.com/stackabletech/listener-operator/pull/237
 [#238]: https://github.com/stackabletech/listener-operator/pull/238
+[#244]: https://github.com/stackabletech/listener-operator/pull/244
 
 ## [24.7.0] - 2024-07-24
 

Cargo.toml

@@ -34,3 +34,4 @@ tracing = "0.1.40"
 [patch."https://github.com/stackabletech/operator-rs.git"]
 # stackable-operator = { path = "../operator-rs/crates/stackable-operator" }
 # stackable-operator = { git = "https://github.com/stackabletech//operator-rs.git", branch = "main" }
+stackable-operator = { git = "https://github.com/stackabletech//operator-rs.git", branch = "feature/smart-preferred-address-type" }

deploy/helm/listener-operator/crds/crds.yaml

@@ -25,14 +25,17 @@ spec:
               description: Defines a policy for how [Listeners](https://docs.stackable.tech/home/nightly/listener-operator/listener) should be exposed. Read the [ListenerClass documentation](https://docs.stackable.tech/home/nightly/listener-operator/listenerclass) for more information.
               properties:
                 preferredAddressType:
-                  default: Hostname
+                  default: HostnameConservative
                   description: |-
-                    Whether addresses should prefer using the IP address (`IP`) or the hostname (`Hostname`).
+                    Whether addresses should prefer using the IP address (`IP`) or the hostname (`Hostname`). Can also be set to `HostnameConservative`, which will use `IP` for `NodePort` service types, but `Hostname` for everything else.
 
-                    The other type will be used if the preferred type is not available. By default `Hostname` is used.
+                    The other type will be used if the preferred type is not available.
+
+                    Defaults to `HostnameConservative`.
                   enum:
                     - Hostname
                     - IP
+                    - HostnameConservative
                   type: string
                 serviceAnnotations:
                   additionalProperties:

docs/modules/listener-operator/pages/listenerclass.adoc

@@ -66,7 +66,7 @@ Additionally, many cloud providers charge for load-balanced traffic.
 [#addresstype]
 == Address types
 
-The Stackable Listener Operator supports both IP addresses and DNS hostnames. The preferred address type for a given ListenerClass can be configured using the `ListenerClass.spec.preferredAddressType` field. If no `preferredAddressType` is specified then it defaults to xref:#addresstype-hostname[].
+The Stackable Listener Operator supports both IP addresses and DNS hostnames. The preferred address type for a given ListenerClass can be configured using the `ListenerClass.spec.preferredAddressType` field. If no `preferredAddressType` is specified then it defaults to xref:#addresstype-hostname-conservative[].
 
 NOTE: If the preferred address type is not supported for a given environment then another type will be used.
 
@@ -81,6 +81,11 @@ but does not require any special client configuration (beyond what the xref:#ser
 
 The DNS hostname of a resource. Clients must be able to resolve these addresses in order to connect, which may require special DNS configuration.
 
+[#addresstype-hostname-conservative]
+=== HostnameConservative
+
+A pseudo-addresstype that is equivalent to xref:#addresstype-ip[] for xref:#servicetype-nodeport[] services, and xref:#addresstype-hostname[] for all others. This means that we default to hostnames where "safe", but don't assume that nodes are resolvable by external clients.
+
 == Default ListenerClasses
 
 The Stackable Data Platform assumes the existence of a few predefined ListenerClasses, and will use them by default as appropriate:

rust/operator-binary/src/csi_server/node.rs

@@ -464,7 +464,7 @@ async fn local_listener_addresses_for_pod(
             })?;
 
         Ok(node_primary_addresses(&node)
-            .pick(listener_class.spec.preferred_address_type)
+            .pick(listener_class.spec.resolve_preferred_address_type())
             .map(|(address, address_type)| ListenerIngress {
                 // nodes: Some(vec![node_name.to_string()]),
                 address: address.to_string(),

rust/operator-binary/src/listener_controller.rs

@@ -364,6 +364,7 @@ pub async fn reconcile(
         .add(&ctx.client, svc)
         .await
         .context(ApplyServiceSnafu { svc: svc_ref })?;
+    let preferred_address_type = listener_class.spec.resolve_preferred_address_type();
 
     let nodes: Vec<Node>;
     let kubernetes_service_fqdn: String;
@@ -384,9 +385,7 @@ pub async fn reconcile(
             .await?;
             addresses = nodes
                 .iter()
-                .flat_map(|node| {
-                    node_primary_addresses(node).pick(listener_class.spec.preferred_address_type)
-                })
+                .flat_map(|node| node_primary_addresses(node).pick(preferred_address_type))
                 .collect::<Vec<_>>();
             ports = svc
                 .spec
@@ -408,7 +407,7 @@ pub async fn reconcile(
                         ip: ingress.ip.as_deref(),
                         hostname: ingress.hostname.as_deref(),
                     }
-                    .pick(listener_class.spec.preferred_address_type)
+                    .pick(preferred_address_type)
                 })
                 .collect();
             ports = svc
@@ -422,7 +421,7 @@ pub async fn reconcile(
         }
         ServiceType::ClusterIP => {
             let cluster_domain = &cluster_info.cluster_domain;
-            addresses = match listener_class.spec.preferred_address_type {
+            addresses = match preferred_address_type {
                 AddressType::Ip => svc
                     .spec
                     .iter()