Ref #25533: support empty pod patches

Author: LEDfan

src/main/java/eu/openanalytics/containerproxy/backend/kubernetes/KubernetesBackend.java

@@ -76,6 +76,7 @@
 import io.fabric8.kubernetes.client.internal.readiness.Readiness;
 import io.fabric8.kubernetes.client.utils.Serialization;
 import org.apache.commons.io.IOUtils;
+import org.apache.commons.lang.StringUtils;
 
 import javax.inject.Inject;
 import javax.json.JsonPatch;
@@ -367,6 +368,10 @@ private JsonPatch readPatchFromSpec(ContainerSpec containerSpec, Proxy proxy) th
 				userService.getCurrentAuth().getCredentials());
 		String expressionAwarePatch = expressionResolver.evaluateToString(patchAsString, context);
 
+		if (StringUtils.isBlank(expressionAwarePatch)) {
+			return null;
+		}
+
 		ObjectMapper yamlReader = new ObjectMapper(new YAMLFactory());
 		yamlReader.registerModule(new JSR353Module());
 		return yamlReader.readValue(expressionAwarePatch, JsonPatch.class);

src/main/java/eu/openanalytics/containerproxy/service/ProxyService.java

@@ -103,8 +103,8 @@ public class ProxyService {
 	@Inject
 	private Environment environment;
 
-    @Inject
-    private ParametersService parametersService;
+	@Inject
+	private RuntimeValueService runtimeValueService;
 
 	private boolean stopAppsOnShutdown;