feature: Checks whether an object is already deleted before attempting to delete it (#65)

BREAKING CHANGE: The return value of the method has changed

Author: lfrancke

src/client.rs

@@ -1,5 +1,7 @@
 use crate::error::OperatorResult;
+use crate::finalizer;
 use crate::label_selector;
+use crate::podutils;
 
 use either::Either;
 use k8s_openapi::apimachinery::pkg::apis::meta::v1::{Condition, LabelSelector};
@@ -229,17 +231,38 @@ impl Client {
             .await?)
     }
 
-    /// Which of the two results this returns depends on the API.
+    /// This deletes a resource _if it is not deleted already_.
+    ///
+    /// It checks whether the resource is already deleted by looking at the `deletion_timestamp`
+    /// of the resource using the [`finalizer::has_deletion_stamp`] method.
+    /// If that is the case it'll return a `Ok(None)`.
+    ///    
+    /// In case the object is actually deleted or marked for deletion there are two possible
+    /// return types.
+    /// Which of the two are returned depends on the API being called.
     /// Take a look at the Kubernetes API reference.
     /// Some `delete` endpoints return the object and others return a `Status` object.
-    pub async fn delete<T>(&self, resource: &T) -> OperatorResult<Either<T, Status>>
+    pub async fn delete<T>(&self, resource: &T) -> OperatorResult<Option<Either<T, Status>>>
     where
         T: Clone + DeserializeOwned + Meta,
     {
-        let api: Api<T> = self.get_api(Meta::namespace(resource));
-        Ok(api
-            .delete(&Meta::name(resource), &self.delete_params)
-            .await?)
+        if finalizer::has_deletion_stamp(resource) {
+            trace!(
+                "Resource ([{}]) already has `deletion_timestamp`, not deleting",
+                podutils::get_log_name(resource)
+            );
+            Ok(None)
+        } else {
+            trace!(
+                "Resource ([{}]) does not have a `deletion_timestamp`, deleting now",
+                podutils::get_log_name(resource)
+            );
+            let api: Api<T> = self.get_api(Meta::namespace(resource));
+            Ok(Some(
+                api.delete(&Meta::name(resource), &self.delete_params)
+                    .await?,
+            ))
+        }
     }
 
     /// Sets a condition on a status.