chore: Consolidate error enums and use expect where possible

CHANGELOG.md

@@ -34,6 +34,7 @@
 - Environment variable overrides (`envOverrides`) are now applied after all environment
   variables set by the operator. In particular, `CONTAINERDEBUG_LOG_DIRECTORY` can now be
   overridden, whereas previously the operator's value always took precedence ([#838]).
+- Make operations infallible where appropriate ([#852]).
 
 ### Fixed
 
@@ -58,6 +59,7 @@
 [#844]: https://github.com/stackabletech/airflow-operator/pull/844
 [#847]: https://github.com/stackabletech/airflow-operator/pull/847
 [#849]: https://github.com/stackabletech/airflow-operator/pull/849
+[#852]: https://github.com/stackabletech/airflow-operator/pull/852
 
 ## [26.7.0] - 2026-07-21
 

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

@@ -693,4 +693,49 @@ mod tests {
         assert_eq!(env.get("AIRFLOW__WEBSERVER__ENABLE_PROXY_FIX"), None);
         assert_eq!(env.get("AIRFLOW__WEBSERVER__PROXY_FIX_X_FOR"), None);
     }
+
+    /// A cluster with the given `spec.clusterConfig.volumeMounts` (as standalone YAML).
+    fn cluster_with_user_volume_mounts(
+        executor_key: &str,
+        executor_config: &str,
+        volume_mounts: &str,
+    ) -> ValidatedCluster {
+        validated_cluster_with(executor_key, executor_config, |cluster| {
+            cluster["spec"]["clusterConfig"]
+                .as_mapping_mut()
+                .expect("clusterConfig is a mapping")
+                .insert(
+                    "volumeMounts".into(),
+                    serde_yaml::from_str(volume_mounts).expect("valid volumeMounts YAML"),
+                );
+        })
+    }
+
+    /// A user-supplied volumeMount that collides with an operator-managed mount path must be
+    /// reported as an error (the operator's own mounts are added first and are infallible).
+    #[test]
+    fn user_volume_mount_colliding_with_config_path_is_an_error() {
+        let cluster = cluster_with_user_volume_mounts(
+            "kubernetesExecutors",
+            "{config: {}}",
+            "[{name: user-volume, mountPath: /stackable/app/config}]",
+        );
+
+        let Err(error) = build(&cluster) else {
+            panic!("the colliding mount must be rejected");
+        };
+        assert!(
+            matches!(
+                error,
+                super::Error::StatefulSet {
+                    source:
+                        crate::controller::build::resource::statefulset::Error::AddVolumeMount { .. },
+                    ..
+                } | super::Error::ExecutorTemplate {
+                    source: crate::controller::build::resource::executor::Error::AddVolumeMount { .. },
+                }
+            ),
+            "unexpected error: {error:?}"
+        );
+    }
 }

rust/operator-binary/src/controller/build/properties/env_vars.rs

@@ -1,6 +1,5 @@
-use std::{collections::BTreeSet, path::PathBuf, str::FromStr};
+use std::{collections::BTreeSet, str::FromStr};
 
-use snafu::Snafu;
 use stackable_operator::{
     constant,
     crd::{authentication::oidc, git_sync},
@@ -81,14 +80,6 @@ constant!(PYTHONPATH: EnvVarName = "PYTHONPATH");
 constant!(CONTAINERDEBUG_LOG_DIRECTORY: EnvVarName = "CONTAINERDEBUG_LOG_DIRECTORY");
 constant!(STACKABLE_POST_HOOK: EnvVarName = "_STACKABLE_POST_HOOK");
 
-#[derive(Snafu, Debug)]
-pub enum Error {
-    #[snafu(display(
-        "failed to construct Git DAG folder - Is the git folder a valid path?: {dag_folder:?}"
-    ))]
-    ConstructGitDagFolder { dag_folder: PathBuf },
-}
-
 /// Return environment variables to be applied to the statefulsets for the scheduler, webserver (and worker,
 /// for clusters utilizing `celeryExecutor`: for clusters using `kubernetesExecutor` a different set will be
 /// used which is defined in [`build_airflow_template_envs`]).

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

@@ -37,12 +37,6 @@ pub enum Error {
         source: webserver_config::Error,
         role_group: RoleGroupName,
     },
-
-    #[snafu(display("failed to build ConfigMap for role group {role_group}"))]
-    BuildConfigMap {
-        source: stackable_operator::builder::configmap::Error,
-        role_group: RoleGroupName,
-    },
 }
 
 /// The rolegroup [`ConfigMap`] configures the rolegroup based on the configuration given by the administrator
@@ -98,7 +92,7 @@ pub fn build_rolegroup_config_map(
         cm_builder.add_data(VECTOR_CONFIG_FILE, vector_config_file_content());
     }
 
-    cm_builder.build().with_context(|_| BuildConfigMapSnafu {
-        role_group: role_group_name.clone(),
-    })
+    Ok(cm_builder
+        .build()
+        .expect("The ConfigMap metadata is set in this function."))
 }

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

@@ -8,11 +8,11 @@ use stackable_operator::{
         meta::ObjectMetaBuilder,
         pod::{PodBuilder, security::PodSecurityContextBuilder},
     },
+    constants::RESTART_CONTROLLER_ENABLED_LABEL,
     k8s_openapi::{
         DeepMerge,
         api::core::v1::{ConfigMap, PodTemplateSpec},
     },
-    kvp::{Label, LabelError},
     v2::{
         builder::pod::container::{EnvVarSet, new_container_builder},
         product_logging::framework::STACKABLE_LOG_DIR,
@@ -55,17 +55,9 @@ pub enum Error {
         source: stackable_operator::builder::pod::container::Error,
     },
 
-    #[snafu(display("failed to build label"))]
-    BuildLabel { source: LabelError },
-
     #[snafu(display("pod template serialization"))]
     PodTemplateSerde { source: serde_yaml::Error },
 
-    #[snafu(display("failed to build the pod template config map"))]
-    PodTemplateConfigMap {
-        source: stackable_operator::builder::configmap::Error,
-    },
-
     #[snafu(display("failed to build shared pod resources"))]
     Pod {
         source: crate::controller::build::resource::pod::Error,
@@ -118,12 +110,6 @@ pub fn build_executor_template_config_map(
     // See https://airflow.apache.org/docs/apache-airflow-providers-cncf-kubernetes/8.4.0/kubernetes_executor.html#base-image
     let mut airflow_container = new_container_builder(&Container::Base.to_container_name());
 
-    add_authentication_volumes_and_volume_mounts(
-        authentication_config,
-        &mut airflow_container,
-        &mut pb,
-    )
-    .context(PodSnafu)?;
     airflow_container
         .image_from_product_image(resolved_product_image)
         .resources(executor_config.resources.clone().into())
@@ -133,13 +119,37 @@ pub fn build_executor_template_config_map(
             &executor_config.logging,
             git_sync_resources,
         ))
-        .add_volume_mounts(cluster.volume_mounts())
-        .context(AddVolumeMountSnafu)?
+        // Statically named operator mounts first: their names and paths are distinct
+        // constants, so they cannot collide with each other.
         .add_volume_mount(&*CONFIG_VOLUME_NAME, CONFIG_PATH)
-        .context(AddVolumeMountSnafu)?
+        .expect("The mount paths are statically defined and there should be no duplicates.")
         .add_volume_mount(&*LOG_CONFIG_VOLUME_NAME, LOG_CONFIG_DIR)
-        .context(AddVolumeMountSnafu)?
+        .expect("The mount paths are statically defined and there should be no duplicates.")
         .add_volume_mount(&*LOG_VOLUME_NAME, STACKABLE_LOG_DIR)
+        .expect("The mount paths are statically defined and there should be no duplicates.");
+
+    // Statically named operator volumes first, for the same reason.
+    pb.add_volumes(volumes::create_volumes(
+        cluster
+            .role_group_resource_names(&EXECUTOR_ROLE_NAME, &EXECUTOR_ROLE_GROUP_NAME)
+            .role_group_config_map()
+            .as_ref(),
+        &executor_config.logging.product_container,
+    ))
+    .expect("The volume names are statically defined and there should be no duplicates.");
+
+    // Authentication mounts and volumes next: their names derive from the AuthenticationClass
+    // contents, so a collision with the static names above surfaces as an error, not a panic.
+    add_authentication_volumes_and_volume_mounts(
+        authentication_config,
+        &mut airflow_container,
+        &mut pb,
+    )
+    .context(PodSnafu)?;
+
+    // User-supplied mounts last: these can collide with the ones above, so this stays fallible.
+    airflow_container
+        .add_volume_mounts(cluster.volume_mounts())
         .context(AddVolumeMountSnafu)?;
 
     add_git_sync_resources(
@@ -157,16 +167,10 @@ pub fn build_executor_template_config_map(
         .add_to_container(&mut airflow_container);
 
     pb.add_container(airflow_container.build());
+    // User-supplied volumes last (fallible); operator-managed and authentication volumes were
+    // added above.
     pb.add_volumes(cluster.volumes().clone())
         .context(AddVolumeSnafu)?;
-    pb.add_volumes(volumes::create_volumes(
-        cluster
-            .role_group_resource_names(&EXECUTOR_ROLE_NAME, &EXECUTOR_ROLE_GROUP_NAME)
-            .role_group_config_map()
-            .as_ref(),
-        &executor_config.logging.product_container,
-    ))
-    .context(AddVolumeSnafu)?;
 
     if let Some(vector_log_config) = &executor_config.logging.vector_container {
         pb.add_container(build_logging_container(
@@ -182,9 +186,6 @@ pub fn build_executor_template_config_map(
 
     let mut cm_builder = ConfigMapBuilder::new();
 
-    let restarter_label =
-        Label::try_from(("restarter.stackable.tech/enabled", "true")).context(BuildLabelSnafu)?;
-
     cm_builder
         .metadata(
             object_meta(
@@ -196,13 +197,15 @@ pub fn build_executor_template_config_map(
                     &EXECUTOR_TEMPLATE_ROLE_GROUP_NAME,
                 ),
             )
-            .with_label(restarter_label)
+            .with_label(RESTART_CONTROLLER_ENABLED_LABEL.clone())
             .build(),
         )
         .add_data(
             TEMPLATE_NAME,
             serde_yaml::to_string(&pod_template).context(PodTemplateSerdeSnafu)?,
         );
 
-    cm_builder.build().context(PodTemplateConfigMapSnafu)
+    Ok(cm_builder
+        .build()
+        .expect("The ConfigMap metadata is set in this function."))
 }

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

@@ -148,3 +148,14 @@ pub(crate) fn build_logging_container(
         EnvVarSet::new(),
     )
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_constants() {
+        // Test that dereferencing the constants does not panic.
+        let _ = *VECTOR_CONTAINER_NAME;
+    }
+}