Merge branch 'master' into kill.dont.stop

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerComposeExecutable.java

@@ -59,6 +59,8 @@ protected String dockerComposePath() {
 
     @Override
     public Process execute(String... commands) throws IOException {
+        DockerForMacHostsIssue.issueWarning();
+
         List<String> args = ImmutableList.<String>builder()
                 .add(dockerComposePath())
                 .addAll(projectName().constructComposeFileCommand())

docker-compose-rule-core/src/main/java/com/palantir/docker/compose/execution/DockerForMacHostsIssue.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2016 Palantir Technologies, Inc. All rights reserved.
+ */
+
+package com.palantir.docker.compose.execution;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.common.io.Files;
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Check whether Mac OS X users have pointed localunixsocket to localhost.
+ *
+ * <p>docker-compose takes an order of magnitude longer to run commands without this tip!
+ *
+ * @see <a href="https://github.com/docker/compose/issues/3419#issuecomment-221793401">Docker Compose Issue #3419</a>
+ */
+public class DockerForMacHostsIssue {
+
+    private static final String REDIRECT_LINE = "127.0.0.1 localunixsocket\n";
+    private static final String WARNING_MESSAGE = "\n\n **** WARNING: Your tests may be slow ****\n"
+            + "Please add the following line to /etc/hosts:\n    "
+            + REDIRECT_LINE
+            + "\nFor more information, see https://github.com/docker/compose/issues/3419#issuecomment-221793401\n\n";
+    private static volatile boolean checkPerformed = false;
+
+    public static void issueWarning() {
+        if (!checkPerformed) {
+            if (onMacOsX() && !localunixsocketRedirectedInEtcHosts()) {
+                System.err.print(WARNING_MESSAGE);
+            }
+        }
+        checkPerformed = true;
+    }
+
+    private static boolean onMacOsX() {
+        return System.getProperty("os.name", "generic").equals("Mac OS X");
+    }
+
+    private static boolean localunixsocketRedirectedInEtcHosts() {
+        try {
+            return Files.toString(new File("/etc/hosts"), UTF_8).contains(REDIRECT_LINE);
+        } catch (IOException e) {
+            return true;  // Better to be silent than issue false warnings
+        }
+    }
+
+    public static void main(String[] args) {
+        issueWarning();
+    }
+
+    private DockerForMacHostsIssue() {}
+}