fix: Revert default cluster domain to 'cluster.local' (#947)

* fix: Revert default cluster domain to 'cluster.local'

* fix: remove recommendations for trailing dot in Kubernetes cluster domain

Author: dervoeti

crates/stackable-operator/CHANGELOG.md

@@ -7,8 +7,10 @@ All notable changes to this project will be documented in this file.
 ### Fixed
 
 - Remove `Merge` trait bound from `erase` and make `product_specific_common_config` public ([#946]).
+- BREAKING: Revert the change of appending a dot to the default cluster domain to make it a FQDN, it is now `cluster.local` again. Users can instead explicitly opt-in to FQDNs via the ENV variable `KUBERNETES_CLUSTER_DOMAIN`. ([#947]).
 
 [#946]: https://github.com/stackabletech/operator-rs/pull/946
+[#947]: https://github.com/stackabletech/operator-rs/pull/947
 
 ## [0.84.0] - 2025-01-16
 

crates/stackable-operator/src/utils/cluster_info.rs

@@ -2,22 +2,18 @@ use std::str::FromStr;
 
 use crate::commons::networking::DomainName;
 
-const KUBERNETES_CLUSTER_DOMAIN_DEFAULT: &str = "cluster.local.";
+const KUBERNETES_CLUSTER_DOMAIN_DEFAULT: &str = "cluster.local";
 
 /// Some information that we know about the Kubernetes cluster.
 #[derive(Debug, Clone)]
 pub struct KubernetesClusterInfo {
-    /// The Kubernetes cluster domain, typically `cluster.local.`.
+    /// The Kubernetes cluster domain, typically `cluster.local`.
     pub cluster_domain: DomainName,
 }
 
 #[derive(clap::Parser, Debug, Default, PartialEq, Eq)]
 pub struct KubernetesClusterInfoOpts {
-    /// Kubernetes cluster domain, usually this is `cluster.local.`.
-    ///
-    /// Please note that we recommend adding a trailing dot (".") to reduce DNS requests, see
-    /// <https://github.com/stackabletech/issues/issues/656> for details.
-    //
+    /// Kubernetes cluster domain, usually this is `cluster.local`.
     // We are not using a default value here, as operators will probably do an more advanced
     // auto-detection of the cluster domain in case it is not specified in the future.
     #[arg(long, env)]
@@ -29,9 +25,6 @@ impl KubernetesClusterInfo {
         let cluster_domain = match &cluster_info_opts.kubernetes_cluster_domain {
             Some(cluster_domain) => {
                 tracing::info!(%cluster_domain, "Using configured Kubernetes cluster domain");
-                if !cluster_domain.ends_with('.') {
-                    tracing::warn!(%cluster_domain, "Your configured Kubernetes cluster domain is not fully qualified (it does not end with a dot (\".\")). We recommend adding a trailing dot to reduce DNS requests, see https://github.com/stackabletech/issues/issues/656 for details");
-                }
 
                 cluster_domain.clone()
             }