Issue #35: UnknownhostException should be retried (#36)

This PR fixes #35 As described in the proposed solution in issue35, this adds UnkownhostException the predicate that decides what is a retryable exception.
pravega · Feb 25, 2021 · 11e9386 · 11e9386
1 parent ea0c29a
commit 11e9386
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Showing 2 changed files with 25 additions and 36 deletions.
diff --git a/client/src/main/java/io/pravega/keycloak/client/KeycloakAuthzClient.java b/client/src/main/java/io/pravega/keycloak/client/KeycloakAuthzClient.java
@@ -29,6 +29,7 @@
 
 import java.io.IOException;
 import java.net.ConnectException;
+import java.net.UnknownHostException;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -138,7 +139,7 @@ private static Predicate<Throwable> isRetryable() {
                     LOG.warn("Retryable HttpResponseException with HTTP code:  {}", statusCode);
                     return true;
                 }
-            } else if (rootCause instanceof ConnectException) {
+            } else if (rootCause instanceof ConnectException || rootCause instanceof UnknownHostException) {
                 LOG.warn("Retryable connection exception", rootCause);
                 return true;
             } else {

diff --git a/client/src/test/java/io/pravega/keycloak/client/KeycloakAuthzClientTest.java b/client/src/test/java/io/pravega/keycloak/client/KeycloakAuthzClientTest.java
@@ -29,6 +29,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.net.ConnectException;
+import java.net.UnknownHostException;
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.HashMap;
@@ -45,7 +46,6 @@
 public class KeycloakAuthzClientTest {
     private static final String SVC_ACCOUNT_JSON_FILE = getResourceFile("service-account.json");
     private static final String SVC_ACCOUNT_JSON_STRING = getResourceString(getResourceFile("service-account.json"));
-    private static final AccessTokenIssuer ISSUER = new AccessTokenIssuer();
 
     @Test
     public void getRPTCacheHits() {
@@ -106,49 +106,22 @@ public void getRPTCannotExchangeAccessTokenForRPT() {
 
     @Test
     public void getRPTWithHttp500Exception() {
-        AuthzClient client = mock(AuthzClient.class, Mockito.RETURNS_DEEP_STUBS);
-        TokenCache tokenCache = spy(new TokenCache(0));
-
-        when(client.obtainAccessToken()).thenThrow(new HttpResponseException("", 500, "", null));
-        KeycloakAuthzClient authzClient = new KeycloakAuthzClient(client, tokenCache, 3, 1);
-        try {
-            authzClient.getRPT();
-            Assert.fail();
-        } catch (RetriesExhaustedException e) {
-        }
-        verify(client, times(3)).obtainAccessToken();
+        assertRetried(new HttpResponseException("", 500, "", null), 3);
     }
 
     @Test
     public void getRPTWithRuntimeConnectException() {
-        AuthzClient client = mock(AuthzClient.class, Mockito.RETURNS_DEEP_STUBS);
-        TokenCache tokenCache = spy(new TokenCache(0));
+        assertRetried(new RuntimeException(new ConnectException()), 3);
+    }
 
-        when(client.obtainAccessToken()).thenThrow(new RuntimeException(new ConnectException()));
-        KeycloakAuthzClient authzClient = new KeycloakAuthzClient(client, tokenCache, 3, 1);
-        try {
-            authzClient.getRPT();
-            Assert.fail();
-        } catch (RetriesExhaustedException e) {
-        }
-        verify(client, times(3)).obtainAccessToken();
+    @Test
+    public void getRPTWithRuntimeUnknownHostException() {
+        assertRetried(new RuntimeException(new UnknownHostException()), 3);
     }
 
     @Test
     public void getRPTWithRandomRuntimeException() {
-        AuthzClient client = mock(AuthzClient.class, Mockito.RETURNS_DEEP_STUBS);
-        TokenCache tokenCache = spy(new TokenCache(0));
-
-        when(client.obtainAccessToken()).thenThrow(new RuntimeException("bogus"));
-        KeycloakAuthzClient authzClient = new KeycloakAuthzClient(client, tokenCache, 3, 1);
-        try {
-            authzClient.getRPT();
-            Assert.fail();
-        } catch (RetriesExhaustedException e) {
-            Assert.fail();
-        } catch (RuntimeException e) {
-        }
-        verify(client, times(1)).obtainAccessToken();
+        assertRetried(new RuntimeException("bogus"), 1);
     }
 
     @Test
@@ -242,6 +215,21 @@ public void checkDeserializeToken() {
         assertEquals(token.getPreferredUsername(), "user-1");
     }
 
+    private void assertRetried(Exception ex, int retries) {
+        AuthzClient client = mock(AuthzClient.class, Mockito.RETURNS_DEEP_STUBS);
+        TokenCache tokenCache = spy(new TokenCache(0));
+
+        when(client.obtainAccessToken()).thenThrow(ex);
+        KeycloakAuthzClient authzClient = new KeycloakAuthzClient(client, tokenCache, 3, 1);
+        try {
+            authzClient.getRPT();
+            Assert.fail();
+        } catch (RetriesExhaustedException e) {
+        } catch (RuntimeException e) {
+        }
+        verify(client, times(retries)).obtainAccessToken();
+    }
+
     private AccessTokenResponse accessTokenResponse() {
         AccessTokenResponse acr = new AccessTokenResponse();
         acr.setToken("TOKEN");