fix: handle single lines terminated by carriage return

A single line terminated by a carriage return caused the resulting
manifest to be invalid.

The code now trims the single lines to ensure the resulting annotation
is compliant with the OCI standard.

Moreover, the debug message was wrong, it was reporting the annotations
to be kept as dropped.

Signed-off-by: Flavio Castelli <fcastelli@suse.com>

Author: flavio

src/push.rs

@@ -9,7 +9,7 @@ use policy_evaluator::{
     },
     policy_metadata::Metadata,
 };
-use tracing::warn;
+use tracing::{debug, warn};
 
 use crate::backend::BackendDetector;
 
@@ -61,16 +61,16 @@ fn build_oci_annotations(annotations: BTreeMap<String, String>) -> BTreeMap<Stri
     let mut annotations: BTreeMap<String, String> = annotations
         .iter()
         .filter(|(k, v)| {
-            let filter = v.lines().count() <= 1;
-            if filter {
+            let keep = v.lines().count() <= 1;
+            if !keep {
                 warn!(
                     annotation = k,
                     "annotation is a multi-line string, it will be removed from the OCI manifest",
                 );
             }
-            filter
+            keep
         })
-        .map(|(k, v)| (k.to_owned(), v.to_owned()))
+        .map(|(k, v)| (k.to_owned(), v.trim().to_owned()))
         .collect();
 
     if let Some(source) = annotations.get(KUBEWARDEN_ANNOTATION_POLICY_SOURCE) {
@@ -82,14 +82,17 @@ fn build_oci_annotations(annotations: BTreeMap<String, String>) -> BTreeMap<Stri
         }
     }
 
+    debug!("OCI annotations: {:?}", annotations);
+
     annotations
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
     use policy_evaluator::constants::{
-        KUBEWARDEN_ANNOTATION_POLICY_URL, KUBEWARDEN_ANNOTATION_POLICY_USAGE,
+        KUBEWARDEN_ANNOTATION_POLICY_DESCRIPTION, KUBEWARDEN_ANNOTATION_POLICY_URL,
+        KUBEWARDEN_ANNOTATION_POLICY_USAGE,
     };
 
     #[test]
@@ -110,6 +113,10 @@ mod tests {
             KUBEWARDEN_ANNOTATION_POLICY_USAGE.to_string(),
             "this is a multi-line\nstring".to_string(),
         );
+        annotations.insert(
+            KUBEWARDEN_ANNOTATION_POLICY_DESCRIPTION.to_string(),
+            "this is a line that ends with a line terminator\n".to_string(),
+        );
 
         let actual = build_oci_annotations(annotations);
 
@@ -126,6 +133,12 @@ mod tests {
             actual.get(KUBEWARDEN_ANNOTATION_POLICY_SOURCE).unwrap(),
             policy_source
         );
+        assert_eq!(
+            actual
+                .get(KUBEWARDEN_ANNOTATION_POLICY_DESCRIPTION)
+                .unwrap(),
+            "this is a line that ends with a line terminator",
+        );
     }
 
     #[test]