From 2f7fcb5c33b3d1a1cbb8ffe286ebb91b59f5dbf6 Mon Sep 17 00:00:00 2001
From: Ioannis Canellos <iocanel@gmail.com>
Date: Tue, 5 Apr 2016 13:03:02 +0300
Subject: [PATCH] Fix potential NPEs in KubernetesDiscoveryClient.

---
 .../discovery/KubernetesDiscoveryClient.java  | 33 +++++++++++--------
 ...ubernetesDiscoveryClientConfiguration.java |  3 +-
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClient.java b/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClient.java
index 58fd2f75..a9b6dbea 100644
--- a/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClient.java
+++ b/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClient.java
@@ -16,11 +16,16 @@
 
 package io.fabric8.spring.cloud.discovery;
 
+import io.fabric8.kubernetes.api.model.Endpoints;
 import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.utils.Utils;
+import org.springframework.cloud.client.DefaultServiceInstance;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.discovery.DiscoveryClient;
+import org.springframework.util.Assert;
 
 import java.util.List;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 public class KubernetesDiscoveryClient implements DiscoveryClient {
@@ -28,11 +33,11 @@ public class KubernetesDiscoveryClient implements DiscoveryClient {
     private static final String HOSTNAME = "HOSTNAME";
 
     private KubernetesClient client;
-    private String localServiceId;
+    private KubernetesDiscoveryProperties properties;
 
-    public KubernetesDiscoveryClient(KubernetesClient client, String localServiceId) {
+    public KubernetesDiscoveryClient(KubernetesClient client, KubernetesDiscoveryProperties properties) {
         this.client = client;
-        this.localServiceId = localServiceId;
+        this.properties = properties;
     }
 
     public KubernetesClient getClient() {
@@ -43,14 +48,6 @@ public class KubernetesDiscoveryClient implements DiscoveryClient {
         this.client = client;
     }
 
-    public String getLocalServiceId() {
-        return localServiceId;
-    }
-
-    public void setLocalServiceId(String localServiceId) {
-        this.localServiceId = localServiceId;
-    }
-
     @Override
     public String description() {
         return "Kubernetes Discovery Client";
@@ -58,17 +55,25 @@ public class KubernetesDiscoveryClient implements DiscoveryClient {
 
     @Override
     public ServiceInstance getLocalServiceInstance() {
+        String serviceName = properties.getServiceName();
         String podName = System.getenv(HOSTNAME);
-        return client.endpoints().withName(localServiceId).get().getSubsets()
+
+        Endpoints endpoints = client.endpoints().withName(serviceName).get();
+        if (Utils.isNullOrEmpty(podName) || endpoints == null) {
+            //TODO: Fallback to something more meaningful.
+            return new DefaultServiceInstance(serviceName, "localhost", 8080, false);
+        }
+        return endpoints.getSubsets()
                 .stream()
                 .filter(s -> s.getAddresses().iterator().next().getIp().equals(podName))
-                .map(s -> new KubernetesServiceInstance(localServiceId, s.getPorts().iterator().next().getName(), s, false))
+                .map(s -> new KubernetesServiceInstance(serviceName, s.getPorts().iterator().next().getName(), s, false))
                 .findFirst().get();
     }
 
     @Override
     public List<ServiceInstance> getInstances(String serviceId) {
-        return client.endpoints().withName(serviceId).get()
+        Assert.notNull(serviceId, "[Assertion failed] - the object argument must be null");
+        return Optional.of(client.endpoints().withName(serviceId).get()).orElse(new Endpoints())
                 .getSubsets()
                 .stream().map(s -> new KubernetesServiceInstance(serviceId, s.getPorts().iterator().next().getName(), s, false))
                 .collect(Collectors.toList());
diff --git a/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClientConfiguration.java b/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClientConfiguration.java
index d9ac8591..e0d01fa1 100644
--- a/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClientConfiguration.java
+++ b/spring-cloud-kubernetes-discovery/src/main/java/io/fabric8/spring/cloud/discovery/KubernetesDiscoveryClientConfiguration.java
@@ -31,11 +31,12 @@ public class KubernetesDiscoveryClientConfiguration {
     @Bean
     @ConditionalOnMissingBean
     public KubernetesDiscoveryClient kubernetesDiscoveryClient(KubernetesClient client, KubernetesDiscoveryProperties properties) {
-        return new KubernetesDiscoveryClient(client, properties.getServiceName());
+        return new KubernetesDiscoveryClient(client, properties);
     }
 
     @Bean
     public KubernetesDiscoveryLifecycle kubernetesDiscoveryLifecycle(KubernetesClient client, KubernetesDiscoveryProperties properties) {
         return new KubernetesDiscoveryLifecycle(client, properties);
+
     }
 }