fix: remove warnings from policy groups.

While testing the group policy feature, it was realized that the warning
messages returned by the policy groups can be confusing. This commit
changes the code to stop adding warnings with the evaluation results
from policy members.

Signed-off-by: José Guilherme Vanz <[email protected]>

src/evaluation/evaluation_environment.rs

@@ -659,16 +659,6 @@ impl EvaluationEnvironment {
         // to define inside of the expression
         let allowed = rhai_engine.eval_expression::<bool>(expression.as_str())?;
 
-        // The API Server puts some limitations on the warnings:
-        // - they cannot exceed 256 characters
-        // - the size of all the warnings cannot exceed 4096 characters
-        // - they are returned as HTTP headers, hence not all characters are allowed
-        //
-        // Because of these reasons, we use the warning struct only to
-        // tell the user whether a member policy was evaluated or not. When it was
-        // evaluated we just tell the outcome (allow/reject).
-        let mut warnings = vec![];
-
         // The details of each policy evaluation are returned as part of the
         // AdmissionResponse.status.details.causes
         let mut status_causes = vec![];
@@ -677,13 +667,6 @@ impl EvaluationEnvironment {
 
         for policy_id in &policy_ids {
             if let Some(result) = evaluation_results.get(policy_id) {
-                let outcome = if result.allowed {
-                    "allowed"
-                } else {
-                    "rejected"
-                };
-                warnings.push(format!("{policy_id}: {outcome}",));
-
                 if !result.allowed {
                     let cause = admission_response::StatusCause {
                         field: Some(format!("spec.policies.{}", policy_id)),
@@ -692,14 +675,11 @@ impl EvaluationEnvironment {
                     };
                     status_causes.push(cause);
                 }
-            } else {
-                warnings.push(format!("{}: not evaluated", policy_id));
             }
         }
         debug!(
             ?policy_id,
             ?allowed,
-            ?warnings,
             ?status_causes,
             "policy group evaluation result"
         );
@@ -727,7 +707,7 @@ impl EvaluationEnvironment {
             patch: None,
             status,
             audit_annotations: None,
-            warnings: Some(warnings),
+            warnings: None,
         })
     }
 }
@@ -1060,11 +1040,6 @@ mod tests {
     #[case::all_policies_are_evaluated(
         "group_policy_with_unhappy_or_bracket_happy_and_unhappy_bracket",
         false,
-        vec![
-            "unhappy_policy_2: rejected",
-            "unhappy_policy_1: rejected",
-            "happy_policy_1: allowed",
-        ],
         vec![
             admission_response::StatusCause {
                 field: Some("spec.policies.unhappy_policy_1".to_string()),
@@ -1081,17 +1056,11 @@ mod tests {
     #[case::not_all_policies_are_evaluated(
         "group_policy_with_unhappy_or_happy_or_unhappy",
         true,
-        vec![
-            "unhappy_policy_1: rejected",
-            "unhappy_policy_2: not evaluated",
-            "happy_policy_1: allowed",
-        ],
         Vec::new(), // no expected causes, since the request is accepted
     )]
     fn group_policy_warning_assignments(
         #[case] policy_id: &str,
         #[case] admission_accepted: bool,
-        #[case] expected_warnings: Vec<&str>,
         #[case] expected_status_causes: Vec<admission_response::StatusCause>,
     ) {
         let policy_id = PolicyID::Policy(policy_id.to_string());
@@ -1111,15 +1080,7 @@ mod tests {
             .validate(&policy_id, &validate_request)
             .expect("should not have errored");
         assert_eq!(response.allowed, admission_accepted);
-
-        let warnings = response.warnings.expect("should have warnings");
-        for expected in expected_warnings {
-            assert!(
-                warnings.iter().any(|w| w.contains(expected)),
-                "could not find warning {}",
-                expected
-            );
-        }
+        assert_eq!(response.warnings, None);
 
         if admission_accepted {
             assert!(response.status.is_none());

tests/integration_test.rs

@@ -122,18 +122,9 @@ async fn test_validate_policy_group(#[case] payload: &str, #[case] expected_allo
                 .message,
         );
     }
+    assert_eq!(admission_review_response.response.warnings, None);
 
-    let warning_messages = &admission_review_response
-        .response
-        .warnings
-        .expect("warning messages should always be filled by policy groups");
-    assert_eq!(1, warning_messages.len());
-
-    let warning_msg = &warning_messages[0];
-    if expected_allowed {
-        assert!(warning_msg.contains("allowed"));
-    } else {
-        assert!(warning_msg.contains("rejected"));
+    if !expected_allowed {
         let causes = admission_review_response
             .response
             .status
@@ -252,13 +243,7 @@ async fn test_validate_policy_group_does_not_do_mutation() {
     );
     assert!(admission_review_response.response.patch.is_none());
 
-    let warning_messages = &admission_review_response
-        .response
-        .warnings
-        .expect("warning messages should always be filled by policy groups");
-    assert_eq!(1, warning_messages.len());
-    let warning_msg = &warning_messages[0];
-    assert!(warning_msg.contains("rejected"));
+    assert_eq!(admission_review_response.response.warnings, None);
 
     let causes = admission_review_response
         .response