#512 Tuned a bit according to comments

src/main/asciidoc/inc/_global-configuration.adoc

@@ -35,9 +35,14 @@ be specified by the certPath or machine configuration, or by the
 | `docker.autoCreate` `CustomNetworks`
 
 | *autoPull*
-| Valid values: `on|off|always|once`. By default external images (base image for building or images to start) are downloaded automatically if they don't exist locally.
-  This feature can be turned off by setting this value to `off`. If you want to check for a newer version of an image and download it if it exists, set this value to `always`.
-  If you are running a `reactor` build, you may set this value to `once` so the image is only checkedn and pulled once for the entire build.
+a| Decide how to pull missing base images or images to start:
+
+ * `on` : Automatic download any missing images (default)
+ * `off` : Automatic pulling is switched off
+ * `always` : Pull images always even when they are already exist locally
+ * `once` : For multi-module builds images are only checked once and pulled for the whole build.
+
+ to `once` so the image is only checkedn and pulled once for the entire build.
 | `docker.autoPull`
 
 | *certPath*

src/main/java/io/fabric8/maven/docker/AbstractDockerMojo.java

@@ -413,7 +413,8 @@ protected void checkImageWithAutoPull(ServiceHub hub, String image, String regis
                                           boolean autoPullAlwaysAllowed) throws DockerAccessException, MojoExecutionException {
         // TODO: further refactoring could be done to avoid referencing the QueryService here
         QueryService queryService = hub.getQueryService();
-        if (!queryService.imageRequiresAutoPull(autoPull, image, autoPullAlwaysAllowed, getPreviouslyPulledImageCache())) {
+        Set<String> previouslyPulledCache = getPreviouslyPulledImageCache();
+        if (!queryService.imageRequiresAutoPull(autoPull, image, autoPullAlwaysAllowed, previouslyPulledCache)) {
             return;
         }
 
@@ -422,6 +423,7 @@ protected void checkImageWithAutoPull(ServiceHub hub, String image, String regis
         long time = System.currentTimeMillis();
         docker.pullImage(withLatestIfNoTag(image), prepareAuthConfig(imageName, registry, false), registry);
         log.info("Pulled %s in %s", imageName.getFullName(), EnvUtil.formatDurationTill(time));
+        previouslyPulledCache.add(image);
 
         if (registry != null && !imageName.hasRegistry()) {
             // If coming from a registry which was not contained in the original name, add a tag from the
@@ -434,8 +436,6 @@ private synchronized Set<String> getPreviouslyPulledImageCache() {
         @SuppressWarnings({ "rawtypes", "unchecked" })
         Set<String> cache = (Set) session.getUserProperties().get(CONTEXT_KEY_PREVIOUSLY_PULLED);
         if (cache == null) {
-            System.out.println("creating new context");
-
             cache = Sets.newConcurrentHashSet();
             session.getUserProperties().put(CONTEXT_KEY_PREVIOUSLY_PULLED, cache);
         }

src/main/java/io/fabric8/maven/docker/service/QueryService.java

@@ -177,7 +177,8 @@ public boolean hasImage(String name) throws DockerAccessException {
      * @param mode the auto pull mode coming from the configuration
      * @param imageName name of the image to check
      * @param always whether to a alwaysPull mode would be active or is always ignored
-     * @return
+     * @return true if the image needs to be pulled, false otherwise
+     *
      * @throws DockerAccessException
      * @throws MojoExecutionException
      */
@@ -209,8 +210,6 @@ private boolean imageRequiresPull(AutoPullMode autoPullMode, String imageName, b
             return false;
         }
 
-        previouslyPulled.add(imageName);
-
         return pullIfNotPresent(autoPullMode, imageName) || alwaysPull(autoPullMode, always);
     }
 

src/main/java/io/fabric8/maven/docker/util/AutoPullMode.java

@@ -45,7 +45,6 @@ public boolean doPullIfNotPresent() {
 
     public boolean alwaysPull() {
         return (this == ONCE || this == ALWAYS);
-
     }
 
     static public AutoPullMode fromString(String val) {

src/test/java/io/fabric8/maven/docker/service/QueryServiceAutoPullTest.java

@@ -107,11 +107,17 @@ public void testPullImageOnce() throws Exception {
         whenCheckIfImageRequiredAutoPull();
         thenImageRequiresPull();
 
+        givenPreviousPullHappened();
+
         givenAnImageExists();
         whenCheckIfImageRequiredAutoPull();
         thenImageDoesNotRequirePull();
     }
 
+    private void givenPreviousPullHappened() {
+        previousImages.add(imageName);
+    }
+
     private void givenAnImageDoesNotExist() throws DockerAccessException {
         this.imageName = "test";