e2e: improve test output on failures

This is mostly marking a bunch of the run methods as helpers so
that the internal assertions they do will show the line number of
the calling test instead.

There's also some small tweaks around the plugin initialization to
help with the output in the event that it fails to make it easier
to debug what went wrong.

Signed-off-by: Milas Bowman <milas.bowman@docker.com>

pkg/e2e/framework.go

@@ -110,36 +110,31 @@ func WithEnv(env ...string) CLIOption {
 
 // initializePlugins copies the necessary plugin files to the temporary config
 // directory for the test.
-func initializePlugins(t testing.TB, d string) {
+func initializePlugins(t testing.TB, configDir string) {
 	t.Helper()
 
 	t.Cleanup(func() {
 		if t.Failed() {
-			conf, _ := ioutil.ReadFile(filepath.Join(d, "config.json"))
+			if conf, err := ioutil.ReadFile(filepath.Join(configDir, "config.json")); err == nil {
-			t.Errorf("Config: %s\n", string(conf))
+				t.Logf("Config: %s\n", string(conf))
-			t.Error("Contents of config dir:")
+			}
-			for _, p := range dirContents(d) {
+			t.Log("Contents of config dir:")
-				t.Errorf(p)
+			for _, p := range dirContents(configDir) {
+				t.Logf("  - %s", p)
 			}
 		}
-		_ = os.RemoveAll(d)
 	})
 
-	_ = os.MkdirAll(filepath.Join(d, "cli-plugins"), 0755)
+	require.NoError(t, os.MkdirAll(filepath.Join(configDir, "cli-plugins"), 0755),
+		"Failed to create cli-plugins directory")
 	composePlugin, err := findExecutable(DockerComposeExecutableName, []string{"../../bin", "../../../bin"})
 	if os.IsNotExist(err) {
-		fmt.Println("WARNING: docker-compose cli-plugin not found")
+		t.Logf("WARNING: docker-compose cli-plugin not found")
 	}
 	if err == nil {
-		err = CopyFile(composePlugin, filepath.Join(d, "cli-plugins", DockerComposeExecutableName))
+		CopyFile(t, composePlugin, filepath.Join(configDir, "cli-plugins", DockerComposeExecutableName))
-		if err != nil {
-			panic(err)
-		}
 		// We don't need a functional scan plugin, but a valid plugin binary
-		err = CopyFile(composePlugin, filepath.Join(d, "cli-plugins", DockerScanExecutableName))
+		CopyFile(t, composePlugin, filepath.Join(configDir, "cli-plugins", DockerScanExecutableName))
-		if err != nil {
-			panic(err)
-		}
 	}
 }
 
@@ -170,26 +165,21 @@ func findExecutable(executableName string, paths []string) (string, error) {
 }
 
 // CopyFile copies a file from a sourceFile to a destinationFile setting permissions to 0755
-func CopyFile(sourceFile string, destinationFile string) error {
+func CopyFile(t testing.TB, sourceFile string, destinationFile string) {
+	t.Helper()
+
 	src, err := os.Open(sourceFile)
-	if err != nil {
+	require.NoError(t, err, "Failed to open source file: %s")
-		return err
-	}
 	// nolint: errcheck
 	defer src.Close()
 
 	dst, err := os.OpenFile(destinationFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0755)
-	if err != nil {
+	require.NoError(t, err, "Failed to open destination file: %s", destinationFile)
-		return err
-	}
 	// nolint: errcheck
 	defer dst.Close()
 
-	if _, err = io.Copy(dst, src); err != nil {
+	_, err = io.Copy(dst, src)
-		return err
+	require.NoError(t, err, "Failed to copy file: %s", sourceFile)
-	}
-
-	return err
 }
 
 // BaseEnvironment provides the minimal environment variables used across all
@@ -229,6 +219,7 @@ func (c *CLI) MetricsSocket() string {
 
 // NewDockerCmd creates a docker cmd without running it
 func (c *CLI) NewDockerCmd(t testing.TB, args ...string) icmd.Cmd {
+	t.Helper()
 	for _, arg := range args {
 		if arg == compose.PluginName {
 			t.Fatal("This test called 'RunDockerCmd' for 'compose'. Please prefer 'RunDockerComposeCmd' to be able to test as a plugin and standalone")
@@ -239,13 +230,15 @@ func (c *CLI) NewDockerCmd(t testing.TB, args ...string) icmd.Cmd {
 
 // RunDockerOrExitError runs a docker command and returns a result
 func (c *CLI) RunDockerOrExitError(t testing.TB, args ...string) *icmd.Result {
-	fmt.Printf("\t[%s] docker %s\n", t.Name(), strings.Join(args, " "))
+	t.Helper()
+	t.Logf("\t[%s] docker %s\n", t.Name(), strings.Join(args, " "))
 	return icmd.RunCmd(c.NewDockerCmd(t, args...))
 }
 
 // RunCmd runs a command, expects no error and returns a result
 func (c *CLI) RunCmd(t testing.TB, args ...string) *icmd.Result {
-	fmt.Printf("\t[%s] %s\n", t.Name(), strings.Join(args, " "))
+	t.Helper()
+	t.Logf("\t[%s] %s\n", t.Name(), strings.Join(args, " "))
 	assert.Assert(t, len(args) >= 1, "require at least one command in parameters")
 	res := icmd.RunCmd(c.NewCmd(args[0], args[1:]...))
 	res.Assert(t, icmd.Success)
@@ -254,7 +247,8 @@ func (c *CLI) RunCmd(t testing.TB, args ...string) *icmd.Result {
 
 // RunCmdInDir runs a command in a given dir, expects no error and returns a result
 func (c *CLI) RunCmdInDir(t testing.TB, dir string, args ...string) *icmd.Result {
-	fmt.Printf("\t[%s] %s\n", t.Name(), strings.Join(args, " "))
+	t.Helper()
+	t.Logf("\t[%s] %s\n", t.Name(), strings.Join(args, " "))
 	assert.Assert(t, len(args) >= 1, "require at least one command in parameters")
 	cmd := c.NewCmd(args[0], args[1:]...)
 	cmd.Dir = dir
@@ -265,6 +259,7 @@ func (c *CLI) RunCmdInDir(t testing.TB, dir string, args ...string) *icmd.Result
 
 // RunDockerCmd runs a docker command, expects no error and returns a result
 func (c *CLI) RunDockerCmd(t testing.TB, args ...string) *icmd.Result {
+	t.Helper()
 	res := c.RunDockerOrExitError(t, args...)
 	res.Assert(t, icmd.Success)
 	return res
@@ -272,6 +267,7 @@ func (c *CLI) RunDockerCmd(t testing.TB, args ...string) *icmd.Result {
 
 // RunDockerComposeCmd runs a docker compose command, expects no error and returns a result
 func (c *CLI) RunDockerComposeCmd(t testing.TB, args ...string) *icmd.Result {
+	t.Helper()
 	res := c.RunDockerComposeCmdNoCheck(t, args...)
 	res.Assert(t, icmd.Success)
 	return res
@@ -279,6 +275,7 @@ func (c *CLI) RunDockerComposeCmd(t testing.TB, args ...string) *icmd.Result {
 
 // RunDockerComposeCmdNoCheck runs a docker compose command, don't presume of any expectation and returns a result
 func (c *CLI) RunDockerComposeCmdNoCheck(t testing.TB, args ...string) *icmd.Result {
+	t.Helper()
 	return icmd.RunCmd(c.NewDockerComposeCmd(t, args...))
 }
 
@@ -317,7 +314,14 @@ func StdoutContains(expected string) func(*icmd.Result) bool {
 }
 
 // WaitForCmdResult try to execute a cmd until resulting output matches given predicate
-func (c *CLI) WaitForCmdResult(t testing.TB, command icmd.Cmd, predicate func(*icmd.Result) bool, timeout time.Duration, delay time.Duration) {
+func (c *CLI) WaitForCmdResult(
+	t testing.TB,
+	command icmd.Cmd,
+	predicate func(*icmd.Result) bool,
+	timeout time.Duration,
+	delay time.Duration,
+) {
+	t.Helper()
 	assert.Assert(t, timeout.Nanoseconds() > delay.Nanoseconds(), "timeout must be greater than delay")
 	var res *icmd.Result
 	checkStopped := func(logt poll.LogT) poll.Result {
@@ -332,7 +336,13 @@ func (c *CLI) WaitForCmdResult(t testing.TB, command icmd.Cmd, predicate func(*i
 }
 
 // WaitForCondition wait for predicate to execute to true
-func (c *CLI) WaitForCondition(t testing.TB, predicate func() (bool, string), timeout time.Duration, delay time.Duration) {
+func (c *CLI) WaitForCondition(
+	t testing.TB,
+	predicate func() (bool, string),
+	timeout time.Duration,
+	delay time.Duration,
+) {
+	t.Helper()
 	checkStopped := func(logt poll.LogT) poll.Result {
 		pass, description := predicate()
 		if !pass {
@@ -351,7 +361,14 @@ func Lines(output string) []string {
 // HTTPGetWithRetry performs an HTTP GET on an `endpoint`, using retryDelay also as a request timeout.
 // In the case of an error or the response status is not the expected one, it retries the same request,
 // returning the response body as a string (empty if we could not reach it)
-func HTTPGetWithRetry(t testing.TB, endpoint string, expectedStatus int, retryDelay time.Duration, timeout time.Duration) string {
+func HTTPGetWithRetry(
+	t testing.TB,
+	endpoint string,
+	expectedStatus int,
+	retryDelay time.Duration,
+	timeout time.Duration,
+) string {
+	t.Helper()
 	var (
 		r   *http.Response
 		err error