chore: Consolidate error enums and use expect where possible

CHANGELOG.md

@@ -23,6 +23,7 @@ All notable changes to this project will be documented in this file.
   are no longer created with the placeholder `app.kubernetes.io/component: none` and
   `app.kubernetes.io/role-group: none` labels.
   StatefulSet selectors and volume claim templates are unchanged, so upgrading is non-breaking.
+- Make operations infallible where appropriate ([#824]).
 
 ### Fixed
 
@@ -39,6 +40,7 @@ All notable changes to this project will be documented in this file.
 [#814]: https://github.com/stackabletech/hdfs-operator/pull/814
 [#819]: https://github.com/stackabletech/hdfs-operator/pull/819
 [#821]: https://github.com/stackabletech/hdfs-operator/pull/821
+[#824]: https://github.com/stackabletech/hdfs-operator/pull/824
 
 ## [26.7.0] - 2026-07-21
 

rust/operator-binary/src/controller/build/resource/config_map.rs

@@ -33,13 +33,6 @@ pub enum Error {
         source: PropertiesWriterError,
         rolegroup: String,
     },
-
-    #[snafu(display("cannot build config map for role {role:?} and role group {role_group:?}"))]
-    Assemble {
-        source: stackable_operator::builder::configmap::Error,
-        role: String,
-        role_group: String,
-    },
 }
 
 type Result<T, E = Error> = std::result::Result<T, E>;
@@ -118,8 +111,7 @@ pub fn build_rolegroup_config_map(
         );
     }
 
-    builder.build().with_context(|_| AssembleSnafu {
-        role: role.to_string(),
-        role_group: role_group_name.to_string(),
-    })
+    Ok(builder
+        .build()
+        .expect("The ConfigMap metadata is set in this function."))
 }

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

@@ -27,11 +27,6 @@ type Result<T, E = Error> = std::result::Result<T, E>;
 
 #[derive(Snafu, Debug)]
 pub enum Error {
-    #[snafu(display("failed to build ConfigMap"))]
-    BuildConfigMap {
-        source: stackable_operator::builder::configmap::Error,
-    },
-
     #[snafu(display("failed to collect the namenode listener refs"))]
     CollectListenerRefs { source: crate::crd::Error },
 }
@@ -88,7 +83,7 @@ pub fn build_discovery_config_map(
             build_discovery_core_site_xml(cluster, cluster_info),
         )
         .build()
-        .context(BuildConfigMapSnafu)?;
+        .expect("The ConfigMap metadata is set in this function.");
 
     Ok(Some(config_map))
 }

rust/operator-binary/src/controller/build/resource/service.rs

@@ -21,11 +21,6 @@ use crate::{
 
 #[derive(Snafu, Debug)]
 pub enum Error {
-    #[snafu(display("failed to build object meta data"))]
-    ObjectMeta {
-        source: stackable_operator::builder::meta::Error,
-    },
-
     #[snafu(display("failed to build roleGroup selector labels"))]
     RoleGroupSelectorLabels { source: LabelError },
 }

rust/operator-binary/src/controller/build/resource/statefulset.rs

@@ -36,9 +36,6 @@ pub enum Error {
 
     #[snafu(display("failed to configure graceful shutdown"))]
     GracefulShutdown { source: graceful_shutdown::Error },
-
-    #[snafu(display("failed to build role-group volume claim templates from config"))]
-    BuildRoleGroupVolumeClaimTemplates { source: container::Error },
 }
 
 pub(crate) fn build_rolegroup_statefulset(
@@ -108,8 +105,7 @@ pub(crate) fn build_rolegroup_statefulset(
     pod_template.merge_from(rolegroup_config.pod_overrides.clone());
 
     // The same comment regarding labels is valid here as it is for the ContainerConfig::add_containers_and_volumes() call above.
-    let pvcs = ContainerConfig::volume_claim_templates(merged_config, &rolegroup_selector_labels)
-        .context(BuildRoleGroupVolumeClaimTemplatesSnafu)?;
+    let pvcs = ContainerConfig::volume_claim_templates(merged_config, &rolegroup_selector_labels);
 
     let statefulset_spec = StatefulSetSpec {
         pod_management_policy: Some("OrderedReady".to_string()),

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

@@ -13,7 +13,7 @@ use stackable_operator::{
     kube::{Resource, api::ObjectMeta},
     v2::{
         HasName, HasUid, NameIsValidLabelValue,
-        role_group_utils::ResourceNames,
+        role_group_utils::{QualifiedRoleGroupName, ResourceNames},
         role_utils::{self, RoleGroupConfig},
         types::{
             kubernetes::{ConfigMapName, NamespaceName, ServiceName, Uid},
@@ -211,6 +211,13 @@ impl ValidatedCluster {
         role: &HdfsNodeRole,
         role_group_name: &RoleGroupName,
     ) -> ServiceName {
+        const _: () = assert!(
+            QualifiedRoleGroupName::MAX_LENGTH <= ServiceName::MAX_LENGTH,
+            "The string `<qualified_role_group_name>` must not exceed the limit of Service names."
+        );
+        let _ = QualifiedRoleGroupName::IS_RFC_1035_LABEL_NAME;
+        let _ = QualifiedRoleGroupName::IS_VALID_LABEL_VALUE;
+
         ServiceName::from_str(
             self.role_group_resource_names(role, role_group_name)
                 .qualified_role_group_name()
@@ -337,3 +344,16 @@ impl ValidatedClusterConfig {
 pub struct ValidatedRoleConfig {
     pub pdb: stackable_operator::commons::pdb::PdbConfig,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_constants() {
+        // Test that dereferencing the constants does not panic.
+        let _ = *PRODUCT_NAME;
+        let _ = *OPERATOR_NAME;
+        let _ = *CONTROLLER_NAME;
+    }
+}

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

@@ -3,7 +3,10 @@ use std::str::FromStr;
 use stackable_operator::{
     constant,
     shared::time::Duration,
-    v2::types::{common::Port, kubernetes::VolumeName},
+    v2::types::{
+        common::Port,
+        kubernetes::{ListenerClassName, VolumeName},
+    },
 };
 
 pub const DEFAULT_DFS_REPLICATION_FACTOR: u8 = 3;
@@ -23,7 +26,7 @@ pub const SERVICE_PORT_NAME_DATA: &str = "data";
 pub const SERVICE_PORT_NAME_METRICS: &str = "metrics";
 pub const SERVICE_PORT_NAME_JMX_METRICS: &str = "jmx-metrics";
 
-pub const DEFAULT_LISTENER_CLASS: &str = "cluster-internal";
+constant!(pub DEFAULT_LISTENER_CLASS: ListenerClassName = "cluster-internal");
 
 pub const DEFAULT_NAME_NODE_METRICS_PORT: Port = Port(8183);
 pub const DEFAULT_NAME_NODE_NATIVE_METRICS_HTTP_PORT: Port = Port(9870);
@@ -91,3 +94,15 @@ pub const DATANODE_ROOT_DATA_DIR_SUFFIX: &str = "/datanode";
 
 constant!(pub LISTENER_VOLUME_NAME: VolumeName = "listener");
 pub const LISTENER_VOLUME_DIR: &str = "/stackable/listener";
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_constants() {
+        // Test that dereferencing the constants does not panic.
+        let _ = *LISTENER_VOLUME_NAME;
+        let _ = *DEFAULT_LISTENER_CLASS;
+    }
+}

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

@@ -19,10 +19,7 @@ use stackable_operator::{
             PvcConfigFragment, Resources, ResourcesFragment,
         },
     },
-    config::{
-        fragment::{Fragment, ValidationError},
-        merge::Merge,
-    },
+    config::{fragment::Fragment, merge::Merge},
     constant,
     crd::listener,
     deep_merger::ObjectOverrides,
@@ -32,7 +29,7 @@ use stackable_operator::{
         self,
         spec::{ContainerLogConfig, Logging},
     },
-    role_utils::{self, GenericRoleConfig},
+    role_utils::GenericRoleConfig,
     schemars::{self, JsonSchema},
     shared::time::Duration,
     status::condition::{ClusterCondition, HasStatusCondition},
@@ -94,27 +91,15 @@ type Result<T, E = Error> = std::result::Result<T, E>;
 
 #[derive(Snafu, Debug)]
 pub enum Error {
-    #[snafu(display("object has no associated namespace"))]
-    NoNamespace,
-
-    #[snafu(display("missing role {role:?}"))]
-    MissingRole { role: String },
-
     #[snafu(display("missing role group {role_group:?} for role {role:?}"))]
     MissingRoleGroup { role: String, role_group: String },
 
-    #[snafu(display("fragment validation failure"))]
-    FragmentValidationFailure { source: ValidationError },
-
     #[snafu(display("port {port} ({port_name:?}) is out of bounds, must be within {range:?}", range = 0..=u16::MAX))]
     PortOutOfBounds {
         source: TryFromIntError,
         port_name: String,
         port: i32,
     },
-
-    #[snafu(display("failed to merge jvm argument overrides"))]
-    MergeJvmArgumentOverrides { source: role_utils::Error },
 }
 
 #[versioned(
@@ -701,12 +686,6 @@ pub enum NameNodeContainer {
     FormatZooKeeper,
 }
 
-/// The default [`ListenerClassName`] used to expose a role group.
-pub fn default_listener_class() -> ListenerClassName {
-    ListenerClassName::from_str(DEFAULT_LISTENER_CLASS)
-        .expect("the default listener class is a valid ListenerClassName")
-}
-
 #[derive(Clone, Debug, Fragment, JsonSchema, PartialEq)]
 #[fragment_attrs(
     derive(
@@ -757,7 +736,7 @@ impl NameNodeConfigFragment {
                 },
             },
             logging: product_logging::spec::default_logging(),
-            listener_class: Some(default_listener_class()),
+            listener_class: Some(DEFAULT_LISTENER_CLASS.clone()),
             common: CommonNodeConfigFragment {
                 affinity: get_affinity(cluster_name, role),
                 graceful_shutdown_timeout: Some(DEFAULT_NAME_NODE_GRACEFUL_SHUTDOWN_TIMEOUT),
@@ -845,7 +824,7 @@ impl DataNodeConfigFragment {
                 )]),
             },
             logging: product_logging::spec::default_logging(),
-            listener_class: Some(default_listener_class()),
+            listener_class: Some(DEFAULT_LISTENER_CLASS.clone()),
             common: CommonNodeConfigFragment {
                 affinity: get_affinity(cluster_name, role),
                 graceful_shutdown_timeout: Some(DEFAULT_DATA_NODE_GRACEFUL_SHUTDOWN_TIMEOUT),
@@ -973,6 +952,14 @@ mod test {
             .expect("storage should be defined")
     }
 
+    #[test]
+    fn test_constants() {
+        // Test that dereferencing the constants does not panic.
+        let _ = *NAMENODE_ROLE_NAME;
+        let _ = *DATANODE_ROLE_NAME;
+        let _ = *JOURNALNODE_ROLE_NAME;
+    }
+
     #[test]
     pub fn test_pvc_rolegroup_from_yaml() {
         let cr = "

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

@@ -3,6 +3,7 @@ use std::str::FromStr;
 use serde::{Deserialize, Serialize};
 use stackable_operator::{
     commons::opa::OpaConfig,
+    constant,
     schemars::{self, JsonSchema},
     v2::types::kubernetes::SecretClassName,
 };
@@ -17,8 +18,12 @@ pub struct AuthenticationConfig {
     pub kerberos: KerberosConfig,
 }
 
+constant!(DEFAULT_TLS_SECRET_CLASS: SecretClassName = "tls");
+
+/// Serde default for `tlsSecretClass`. Kept as a function because `#[serde(default = "...")]`
+/// requires a function path.
 fn default_tls_secret_class() -> SecretClassName {
-    SecretClassName::from_str("tls").expect("\"tls\" should be a valid SecretClassName")
+    DEFAULT_TLS_SECRET_CLASS.clone()
 }
 
 #[derive(Clone, Debug, Deserialize, Eq, JsonSchema, PartialEq, Serialize)]
@@ -34,3 +39,14 @@ pub struct AuthorizationConfig {
     // No doc - it's in the struct.
     pub opa: OpaConfig,
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_constants() {
+        // Test that dereferencing the constants does not panic.
+        let _ = *DEFAULT_TLS_SECRET_CLASS;
+    }
+}

rust/operator-binary/src/hdfs_controller.rs

@@ -10,7 +10,6 @@ use stackable_operator::{
         core::{DeserializeGuard, error_boundary},
         runtime::{controller::Action, events::Recorder},
     },
-    kvp::LabelError,
     logging::controller::ReconcilerError,
     shared::time::Duration,
 };
@@ -55,9 +54,6 @@ pub enum Error {
     #[snafu(display("failed to create cluster event"))]
     FailedToCreateClusterEvent { source: crate::event::Error },
 
-    #[snafu(display("failed to build cluster resources label"))]
-    BuildClusterResourcesLabel { source: LabelError },
-
     #[snafu(display("HdfsCluster object is invalid"))]
     InvalidHdfsCluster {
         source: error_boundary::InvalidObject,