Break some routines out of the mutable files test for future use

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)

integration-cli/docker_cli_run_test.go

@@ -1897,37 +1897,25 @@ func TestRunMutableNetworkFiles(t *testing.T) {
 	for _, fn := range []string{"resolv.conf", "hosts"} {
 		deleteAllContainers()
 
-		out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-d", "--name", "c1", "busybox", "sh", "-c", fmt.Sprintf("echo success >/etc/%s; while true; do sleep 1; done", fn)))
-		if err != nil {
-			t.Fatal(err, out)
-		}
-
-		time.Sleep(1 * time.Second)
-
-		contID := strings.TrimSpace(out)
-
-		f, err := os.Open(filepath.Join("/var/lib/docker/containers", contID, fn))
+		content, err := runCommandAndReadContainerFile(fn, exec.Command(dockerBinary, "run", "-d", "--name", "c1", "busybox", "sh", "-c", fmt.Sprintf("echo success >/etc/%s; while true; do sleep 1; done", fn)))
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		content, err := ioutil.ReadAll(f)
-		f.Close()
-
 		if strings.TrimSpace(string(content)) != "success" {
 			t.Fatal("Content was not what was modified in the container", string(content))
 		}
 
-		out, _, err = runCommandWithOutput(exec.Command(dockerBinary, "run", "-d", "--name", "c2", "busybox", "sh", "-c", fmt.Sprintf("while true; do cat /etc/%s; sleep 1; done", fn)))
+		out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "run", "-d", "--name", "c2", "busybox", "sh", "-c", fmt.Sprintf("while true; do cat /etc/%s; sleep 1; done", fn)))
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		contID = strings.TrimSpace(out)
+		contID := strings.TrimSpace(out)
 
-		resolvConfPath := filepath.Join("/var/lib/docker/containers", contID, fn)
+		resolvConfPath := containerStorageFile(contID, fn)
 
-		f, err = os.OpenFile(resolvConfPath, os.O_WRONLY|os.O_SYNC|os.O_APPEND, 0644)
+		f, err := os.OpenFile(resolvConfPath, os.O_WRONLY|os.O_SYNC|os.O_APPEND, 0644)
 		if err != nil {
 			t.Fatal(err)
 		}

integration-cli/docker_test_vars.go

@@ -16,10 +16,11 @@ var (
 	// the private registry to use for tests
 	privateRegistryURL = "127.0.0.1:5000"
 
-	dockerBasePath     = "/var/lib/docker"
-	execDriverPath     = dockerBasePath + "/execdriver/native"
-	volumesConfigPath  = dockerBasePath + "/volumes"
-	volumesStoragePath = dockerBasePath + "/vfs/dir"
+	dockerBasePath       = "/var/lib/docker"
+	execDriverPath       = dockerBasePath + "/execdriver/native"
+	volumesConfigPath    = dockerBasePath + "/volumes"
+	volumesStoragePath   = dockerBasePath + "/vfs/dir"
+	containerStoragePath = dockerBasePath + "/containers"
 
 	workingDirectory string
 )

integration-cli/docker_utils.go

@@ -731,3 +731,35 @@ func readFile(src string, t *testing.T) (content string) {
 	}
 	return string(data)
 }
+
+func containerStorageFile(containerId, basename string) string {
+	return filepath.Join("/var/lib/docker/containers", containerId, basename)
+}
+
+func runCommandAndReadContainerFile(filename string, cmd *exec.Cmd) ([]byte, error) {
+	out, _, err := runCommandWithOutput(cmd)
+	if err != nil {
+		return nil, err
+	}
+
+	time.Sleep(1 * time.Second)
+
+	contID := strings.TrimSpace(out)
+
+	return readContainerFile(contID, filename)
+}
+
+func readContainerFile(containerId, filename string) ([]byte, error) {
+	f, err := os.Open(containerStorageFile(containerId, filename))
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	content, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+
+	return content, nil
+}