Fix for Issue 64

plugin/src/main/java/com/spotify/plugin/dockerfile/AbstractDockerMojo.java

@@ -26,6 +26,7 @@
 import com.google.common.io.Files;
 import com.spotify.docker.client.DefaultDockerClient;
 import com.spotify.docker.client.DockerClient;
+import com.spotify.docker.client.DockerConfigReader;
 import com.spotify.docker.client.auth.ConfigFileRegistryAuthSupplier;
 import com.spotify.docker.client.auth.MultiRegistryAuthSupplier;
 import com.spotify.docker.client.auth.RegistryAuthSupplier;
@@ -94,6 +95,18 @@ public String getFileName() {
       property = "dockerfile.dockerInfoDirectory", required = true)
   protected File dockerInfoDirectory;
 
+  /**
+   * Path to docker config file, if the default is not acceptable.
+   */
+  @Parameter(property = "dockerfile.dockerConfigFile")
+  protected File dockerConfigFile;
+
+  /**
+   * A maven server id, in order to use maven settings to supply server auth.
+   */
+  @Parameter(defaultValue = "false", property = "dockerfile.useMavenSettingsForAuth")
+  protected boolean useMavenSettingsForAuth;
+
   /**
    * Directory where test metadata will be written during build.
    */
@@ -407,7 +420,21 @@ private DockerClient openDockerClient() throws MojoExecutionException {
   @Nonnull
   private RegistryAuthSupplier createRegistryAuthSupplier() {
     final List<RegistryAuthSupplier> suppliers = new ArrayList<>();
-    suppliers.add(new ConfigFileRegistryAuthSupplier());
+
+    if (useMavenSettingsForAuth) {
+      suppliers.add(new MavenRegistryAuthSupplier(session.getSettings()));
+    }
+
+    if (dockerConfigFile == null || "".equals(dockerConfigFile.getName())) {
+      suppliers.add(new ConfigFileRegistryAuthSupplier());
+    } else {
+      suppliers.add(
+          new ConfigFileRegistryAuthSupplier(
+            new DockerConfigReader(),
+            dockerConfigFile.toPath()
+          )
+      );
+    }
 
     if (googleContainerRegistryEnabled) {
       try {

plugin/src/main/java/com/spotify/plugin/dockerfile/MavenRegistryAuthSupplier.java

@@ -0,0 +1,79 @@
+/*-
+ * -\-\-
+ * Dockerfile Maven Plugin
+ * --
+ * Copyright (C) 2017 Spotify AB
+ * --
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * -/-/-
+ */
+
+package com.spotify.plugin.dockerfile;
+
+import com.spotify.docker.client.ImageRef;
+import com.spotify.docker.client.auth.RegistryAuthSupplier;
+import com.spotify.docker.client.exceptions.DockerException;
+import com.spotify.docker.client.messages.RegistryAuth;
+import com.spotify.docker.client.messages.RegistryConfigs;
+import java.util.HashMap;
+import java.util.Map;
+import org.apache.maven.settings.Server;
+import org.apache.maven.settings.Settings;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MavenRegistryAuthSupplier implements RegistryAuthSupplier {
+
+  private static final Logger log = LoggerFactory.getLogger(MavenRegistryAuthSupplier.class);
+
+  private final Settings settings;
+
+  public MavenRegistryAuthSupplier(final Settings settings) {
+    this.settings = settings;
+  }
+
+  @Override
+  public RegistryAuth authFor(final String imageName) throws DockerException {
+    final ImageRef ref = new ImageRef(imageName);
+    Server server = settings.getServer(ref.getRegistryName());
+    if (server != null) {
+      return RegistryAuth.builder()
+        .username(server.getUsername())
+        .password(server.getPassword())
+        .build();
+    }
+    log.warn("Did not find maven server configuration for docker server " + ref.getRegistryName());
+    return null;
+  }
+
+  @Override
+  public RegistryAuth authForSwarm() throws DockerException {
+    return null;
+  }
+
+  @Override
+  public RegistryConfigs authForBuild() throws DockerException {
+    final Map<String, RegistryAuth> allConfigs = new HashMap<>();
+    for (Server server : settings.getServers()) {
+      allConfigs.put(
+          server.getId(),
+          RegistryAuth.builder()
+            .username(server.getUsername())
+            .password(server.getPassword())
+            .build()
+      );
+    }
+    return RegistryConfigs.create(allConfigs);
+  }
+
+}