Add response body checking to HttpWaitStrategy (#441)

Add forResponsePredicate() method to HttpWaitStrategy class.

Author: barrycommins

CHANGELOG.md

@@ -9,13 +9,13 @@ All notable changes to this project will be documented in this file.
 - Stopping creation of temporary directory prior to creating temporary file (#443)
 
 ### Changed
+- Added `forResponsePredicate` method to HttpWaitStrategy to test response body (#441)
 - Changed `DockerClientProviderStrategy` to be loaded via Service Loader (#434, #435)
 - Made it possible to specify docker compose container in configuration (#422, #425)
 - Clarified wording of pre-flight check messages (#457, #436)
 - Added caching of failure to find a docker daemon, so that subsequent tests fail fast. This is likely to be a significant improvement in situations where there is no docker daemon available, dramatically reducing run time and log output when further attempts to find the docker daemon cannot succeed.
 - Allowing JDBC containers' username, password and DB name to be customized (#400, #354)
 
-
 ## [1.4.2] - 2017-07-25
 ### Fixed
 - Worked around incompatibility between Netty's Unix socket support and OS X 10.11. Reinstated use of TCP-Unix Socket proxy when running on OS X prior to v10.12. (Fixes #402)

core/src/main/java/org/testcontainers/containers/wait/HttpWaitStrategy.java

@@ -3,15 +3,17 @@
 import com.google.common.base.Strings;
 import com.google.common.io.BaseEncoding;
 import org.rnorth.ducttape.TimeoutException;
-import org.testcontainers.DockerClientFactory;
 import org.testcontainers.containers.ContainerLaunchException;
 import org.testcontainers.containers.GenericContainer;
 
+import java.io.BufferedReader;
 import java.io.IOException;
+import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URI;
 import java.net.URL;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Predicate;
 
 import static org.rnorth.ducttape.unreliables.Unreliables.retryUntilSuccess;
 
@@ -36,6 +38,7 @@ public class HttpWaitStrategy extends GenericContainer.AbstractWaitStrategy {
     private boolean tlsEnabled;
     private String username;
     private String password;
+    private Predicate<String> responsePredicate;
 
     /**
      * Waits for the given status code.
@@ -82,6 +85,16 @@ public HttpWaitStrategy withBasicCredentials(String username, String password) {
         return this;
     }
 
+    /**
+     * Waits for the response to pass the given predicate
+     * @param responsePredicate The predicate to test the response against
+     * @return this
+     */
+    public HttpWaitStrategy forResponsePredicate(Predicate<String> responsePredicate) {
+        this.responsePredicate = responsePredicate;
+        return this;
+    }
+
     @Override
     protected void waitUntilReady() {
         final Integer livenessCheckPort = getLivenessCheckPort();
@@ -114,6 +127,14 @@ protected void waitUntilReady() {
                                     connection.getResponseCode()));
                         }
 
+                        if(responsePredicate != null) {
+                            String responseBody = getResponseBody(connection);
+                            if(!responsePredicate.test(responseBody)) {
+                                throw new RuntimeException(String.format("Response: %s did not match predicate",
+                                        responseBody));
+                            }
+                        }
+
                     } catch (IOException e) {
                         throw new RuntimeException(e);
                     }
@@ -155,4 +176,20 @@ private URI buildLivenessUri(int livenessCheckPort) {
     private String buildAuthString(String username, String password) {
         return AUTH_BASIC + BaseEncoding.base64().encode((username + ":" + password).getBytes());
     }
+
+    private String getResponseBody(HttpURLConnection connection) throws IOException {
+        BufferedReader reader;
+        if (200 <= connection.getResponseCode() && connection.getResponseCode() <= 299) {
+            reader = new BufferedReader(new InputStreamReader((connection.getInputStream())));
+        } else {
+            reader = new BufferedReader(new InputStreamReader((connection.getErrorStream())));
+        }
+
+        StringBuilder builder = new StringBuilder();
+        String line;
+        while ((line = reader.readLine()) != null) {
+            builder.append(line);
+        }
+        return builder.toString();
+    }
 }

core/src/test/java/org/testcontainers/junit/wait/HttpWaitStrategyTest.java

@@ -14,16 +14,18 @@
  */
 public class HttpWaitStrategyTest extends AbstractWaitStrategyTest<HttpWaitStrategy> {
     /**
-     * Doubly-escaped newline sequence indicating end of the HTTP header.
+     * newline sequence indicating end of the HTTP header.
      */
-    private static final String DOUBLE_NEWLINE = "\\\r\\\n\\\r\\\n";
+    private static final String NEWLINE = "\r\n";
+
+    private static final String GOOD_RESPONSE_BODY = "Good Response Body";
 
     /**
      * Expects that the WaitStrategy returns successfully after receiving an HTTP 200 response from the container.
      */
     @Test
     public void testWaitUntilReady_Success() {
-        waitUntilReadyAndSucceed("while true; do echo -e \"HTTP/1.1 200 OK" + DOUBLE_NEWLINE + "\" | nc -lp 8080; done");
+        waitUntilReadyAndSucceed(createShellCommand("200 OK", GOOD_RESPONSE_BODY));
     }
 
     /**
@@ -32,7 +34,16 @@ public void testWaitUntilReady_Success() {
      */
     @Test
     public void testWaitUntilReady_Timeout() {
-        waitUntilReadyAndTimeout("while true; do echo -e \"HTTP/1.1 400 Bad Request" + DOUBLE_NEWLINE + "\" | nc -lp 8080; done");
+        waitUntilReadyAndTimeout(createShellCommand("400 Bad Request", GOOD_RESPONSE_BODY));
+    }
+
+    /**
+     * Expects that the WaitStrategy throws a {@link RetryCountExceededException} after not the expected response body
+     * from the container within the timeout period.
+     */
+    @Test
+    public void testWaitUntilReady_Timeout_BadResponseBody() {
+        waitUntilReadyAndTimeout(createShellCommand("200 OK", "Bad Response"));
     }
 
     /**
@@ -48,6 +59,14 @@ protected void waitUntilReady() {
                 super.waitUntilReady();
                 ready.set(true);
             }
-        };
+        }.forResponsePredicate(s -> s.equals(GOOD_RESPONSE_BODY));
+    }
+
+    private String createShellCommand(String header, String responseBody) {
+        int length = responseBody.getBytes().length;
+        return "while true; do { echo -e \"HTTP/1.1 "+header+NEWLINE+
+                "Content-Type: text/html"+NEWLINE+
+                "Content-Length: "+length +NEWLINE+ "\";"
+                +" echo \""+responseBody+"\";} | nc -lp 8080; done";
     }
 }