From b2e95a6457278943eca47193595d112cd680348b Mon Sep 17 00:00:00 2001
From: Lari Hotari <lhotari@apache.org>
Date: Thu, 24 Jun 2021 01:18:37 +0300
Subject: [PATCH] Enable Function subscription naming workaround when activated

The Pulsar Function will use the function name as the subscription name when this workaround
is activated. This workaround is activated when -DdsPatchFunctionNameAsSubscriptionName=true
system property or dsPatchFunctionNameAsSubscriptionName=true environment variable is passed
to the Functions Worker (or to the Pulsar Broker when there isn't a separate Functions Worker).
---
 .../functions/utils/FunctionConfigUtils.java  | 21 ++++++++++++++++++-
 .../functions/utils/SinkConfigUtils.java      |  4 ++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/FunctionConfigUtils.java b/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/FunctionConfigUtils.java
index 6b9b7628f9332..93a8d80d5eec0 100644
--- a/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/FunctionConfigUtils.java
+++ b/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/FunctionConfigUtils.java
@@ -54,11 +54,26 @@ public class FunctionConfigUtils {
 	static final Integer MAX_PENDING_ASYNC_REQUESTS_DEFAULT = Integer.valueOf(1000);
 	static final Boolean FORWARD_SOURCE_MESSAGE_PROPERTY_DEFAULT = Boolean.TRUE;
 
+    /*
+    Enable Function subscription naming workaround when activated
+
+    The Pulsar Function will use the function name as the subscription name when this workaround
+    is activated. This workaround is activated when -DdsPatchFunctionNameAsSubscriptionName=true
+    system property or dsPatchFunctionNameAsSubscriptionName=true environment variable is passed
+    to the Functions Worker (or to the Pulsar Broker when there isn't a separate Functions Worker).
+    */
+    private static final String FLAG_NAME_DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME =
+            "dsPatchFunctionNameAsSubscriptionName";
+    static final boolean DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME = Boolean.valueOf(System.getProperty(
+            FLAG_NAME_DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME, Boolean.FALSE.toString()))
+            || Boolean.valueOf(System.getenv().getOrDefault(FLAG_NAME_DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME,
+            Boolean.FALSE.toString()));
+
     private static final ObjectMapper OBJECT_MAPPER = ObjectMapperFactory.create();
 
     public static FunctionDetails convert(FunctionConfig functionConfig, ClassLoader classLoader)
             throws IllegalArgumentException {
-        
+
         boolean isBuiltin = !org.apache.commons.lang3.StringUtils.isEmpty(functionConfig.getJar()) && functionConfig.getJar().startsWith(org.apache.pulsar.common.functions.Utils.BUILTIN);
 
         Class<?>[] typeArgs = null;
@@ -155,6 +170,8 @@ public static FunctionDetails convert(FunctionConfig functionConfig, ClassLoader
         // Set subscription name
         if (isNotBlank(functionConfig.getSubName())) {
             sourceSpecBuilder.setSubscriptionName(functionConfig.getSubName());
+        } else if (DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME) {
+            sourceSpecBuilder.setSubscriptionName(functionConfig.getName());
         }
 
         // Set subscription position
@@ -348,6 +365,8 @@ public static FunctionConfig convertFromDetails(FunctionDetails functionDetails)
         functionConfig.setInputSpecs(consumerConfigMap);
         if (!isEmpty(functionDetails.getSource().getSubscriptionName())) {
             functionConfig.setSubName(functionDetails.getSource().getSubscriptionName());
+        } else if (DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME) {
+            functionConfig.setSubName(functionDetails.getName());
         }
         functionConfig.setRetainOrdering(functionDetails.getRetainOrdering());
         functionConfig.setRetainKeyOrdering(functionDetails.getRetainKeyOrdering());
diff --git a/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/SinkConfigUtils.java b/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/SinkConfigUtils.java
index e046537fb0218..270efe3f550f2 100644
--- a/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/SinkConfigUtils.java
+++ b/pulsar-functions/utils/src/main/java/org/apache/pulsar/functions/utils/SinkConfigUtils.java
@@ -158,6 +158,8 @@ public static FunctionDetails convert(SinkConfig sinkConfig, ExtractedSinkDetail
         }
         if (isNotBlank(sinkConfig.getSourceSubscriptionName())) {
             sourceSpecBuilder.setSubscriptionName(sinkConfig.getSourceSubscriptionName());
+        }  else if (FunctionConfigUtils.DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME) {
+            sourceSpecBuilder.setSubscriptionName(sinkConfig.getName());
         }
 
         Function.SubscriptionType subType = ((sinkConfig.getRetainOrdering() != null && sinkConfig.getRetainOrdering())
@@ -274,6 +276,8 @@ public static SinkConfig convertFromDetails(FunctionDetails functionDetails) {
         sinkConfig.setInputSpecs(consumerConfigMap);
         if (!isEmpty(functionDetails.getSource().getSubscriptionName())) {
             sinkConfig.setSourceSubscriptionName(functionDetails.getSource().getSubscriptionName());
+        } else if (FunctionConfigUtils.DS_PATCH_FUNCTION_NAME_AS_SUBSCRIPTION_NAME) {
+            sinkConfig.setSourceSubscriptionName(functionDetails.getName());
         }
         if (functionDetails.getSource().getSubscriptionType() == Function.SubscriptionType.FAILOVER) {
             sinkConfig.setRetainOrdering(true);