Allow configuring the AlwaysPullPolicy (#10188)

Author: sebastian-steiner

core/src/main/java/org/testcontainers/images/PullPolicy.java

@@ -40,7 +40,7 @@ public static synchronized ImagePullPolicy defaultPolicy() {
                         .currentThread()
                         .getContextClassLoader()
                         .loadClass(imagePullPolicyClassName)
-                        .getConstructor()
+                        .getDeclaredConstructor()
                         .newInstance();
             } catch (Exception e) {
                 throw new IllegalArgumentException(

core/src/test/java/org/testcontainers/images/OverrideImagePullPolicyTest.java

@@ -51,4 +51,20 @@ public void simpleConfigurationTest() {
             container.stop();
         }
     }
+
+    @Test
+    public void alwaysPullConfigurationTest() {
+        Mockito
+            .doReturn(AlwaysPullPolicy.class.getCanonicalName())
+            .when(TestcontainersConfiguration.getInstance())
+            .getImagePullPolicy();
+
+        try (DockerRegistryContainer registry = new DockerRegistryContainer()) {
+            registry.start();
+            GenericContainer<?> container = new GenericContainer<>(registry.createImage()).withExposedPorts(8080);
+            container.start();
+            assertThat(container.getImage().imagePullPolicy).isInstanceOf(AlwaysPullPolicy.class);
+            container.stop();
+        }
+    }
 }

docs/features/advanced_options.md

@@ -38,6 +38,14 @@ You can also configure Testcontainers to use your custom implementation by using
     pull.policy=com.mycompany.testcontainers.ExampleImagePullPolicy
     ```
 
+You can also use the provided implementation to always pull images
+
+=== "`src/test/resources/testcontainers.properties`"
+    ```text
+    pull.policy=org.testcontainers.images.AlwaysPullPolicy
+    ```
+
+
 Please see [the documentation on configuration mechanisms](./configuration.md) for more information.
 
 ## Customizing the container