Pin image sha for testing and fix volume expectations

Author: felipecrs

src/test/java/org/jenkinsci/plugins/docker/workflow/client/DockerClientTest.java

@@ -57,19 +57,22 @@ public void setup() throws Exception {
 
     @Test
     public void test_run() throws IOException, InterruptedException {
+        // Pin to a specific sha256 hash of the image to avoid any potential issues with the image changing in the future.
+        // Original image tag: docker:20.10.9-dind
+        String image = "docker.io/library/docker@sha256:d842418d21545fde57c2512681d9bdc4ce0e54f2e0305a293ee20a9b6166932b";
         EnvVars launchEnv = DockerTestUtil.newDockerLaunchEnv();
         String containerId =
-                dockerClient.run(launchEnv, "docker:20.10.9-dind", null, null, Collections.<String, String>emptyMap(), Collections.<String>emptyList(), new EnvVars(),
+                dockerClient.run(launchEnv, image, null, null, Collections.<String, String>emptyMap(), Collections.<String>emptyList(), new EnvVars(),
                         dockerClient.whoAmI(), "cat");
         Assert.assertEquals(64, containerId.length());
         ContainerRecord containerRecord = dockerClient.getContainerRecord(launchEnv, containerId);
-        Assert.assertEquals(dockerClient.inspect(launchEnv, "docker:20.10.9-dind", ".Id"), containerRecord.getImageId());
+        Assert.assertEquals(dockerClient.inspect(launchEnv, image, ".Id"), containerRecord.getImageId());
         Assert.assertTrue(containerRecord.getContainerName().length() > 0);
         Assert.assertTrue(containerRecord.getHost().length() > 0);
         Assert.assertTrue(containerRecord.getCreated() > 1000000000000L);
-        Assert.assertEquals(Collections.<String>emptyList(), dockerClient.getVolumes(launchEnv, containerId));
 
-        // Check that an anonymous volume was created
+        // Check that an anonymous volume was created mounted at /var/lib/docker
+        Assert.assertEquals(Collections.<String>singletonList("/var/lib/docker"), dockerClient.getVolumes(launchEnv, containerId));
         String anonymousVolumeName = dockerClient.inspect(launchEnv, containerId, "range .Mounts }}{{ .Name }}{{ end");
         Assert.assertEquals(64, anonymousVolumeName.length());