tolerate invalid cni caches for deletion

Signed-off-by: Henry Wang <henwang@amazon.com>

libcni/api.go

@@ -586,9 +586,9 @@ func (c *CNIConfig) DelNetworkList(ctx context.Context, list *NetworkConfigList,
 	if gtet, err := version.GreaterThanOrEqualTo(list.CNIVersion, "0.4.0"); err != nil {
 		return err
 	} else if gtet {
-		cachedResult, err = c.getCachedResult(list.Name, list.CNIVersion, rt)
-		if err != nil {
-			return fmt.Errorf("failed to get network %q cached result: %w", list.Name, err)
+		if cachedResult, err = c.getCachedResult(list.Name, list.CNIVersion, rt); err != nil {
+			_ = c.cacheDel(list.Name, rt)
+			cachedResult = nil
 		}
 	}
 
@@ -598,7 +598,10 @@ func (c *CNIConfig) DelNetworkList(ctx context.Context, list *NetworkConfigList,
 			return fmt.Errorf("plugin %s failed (delete): %w", pluginDescription(net.Network), err)
 		}
 	}
-	_ = c.cacheDel(list.Name, rt)
+
+	if cachedResult != nil {
+		_ = c.cacheDel(list.Name, rt)
+	}
 
 	return nil
 }

libcni/api_test.go

@@ -1474,15 +1474,15 @@ var _ = Describe("Invoking plugins", func() {
 			})
 
 			Context("when the cached result is invalid", func() {
-				It("returns an error", func() {
+				It("tolerates the error", func() {
 					cacheFile := resultCacheFilePath(cacheDirPath, netConfigList.Name, runtimeConfig)
 					err := os.MkdirAll(filepath.Dir(cacheFile), 0o700)
 					Expect(err).NotTo(HaveOccurred())
 					err = os.WriteFile(cacheFile, []byte("adfadsfasdfasfdsafaf"), 0o600)
 					Expect(err).NotTo(HaveOccurred())
 
 					err = cniConfig.DelNetworkList(ctx, netConfigList, runtimeConfig)
-					Expect(err).To(MatchError("failed to get network \"some-list\" cached result: decoding version from network config: invalid character 'a' looking for beginning of value"))
+					Expect(err).NotTo(HaveOccurred())
 				})
 			})
 		})