introduce golden file test helper

lib/utils/golden/golden.go

@@ -0,0 +1,128 @@
+/*
+Copyright 2022 Gravitational, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Golden files are a convenient way of storing data that we want to assert in
+// unit tests. They are stored under the `testdata/` directory in a directory
+// based on the name of the test. They are especially useful for storing large
+// pieces of data that can be unwieldy to embed directly into your test tables.
+//
+// The convenience factor comes from the update mode which causes the tests to
+// write data, rather than assert against it. This allows expected outputs
+// to be updated easily when the underlying implementation is adjusted.
+// This mode can be enabled by setting `GOLDEN_UPDATE=1` when running the tests
+// you wish to update.
+//
+// Usage:
+//
+// Golden is ideal for testing the results of marshalling, or units that output
+// large amounts of data to stdout or a file:
+//
+// 	func TestMarshalFooStruct(t *testing.T) {
+//		got, err := json.Marshal(FooStruct{Some: "Data"})
+//		require.NoError(t, err)
+//
+//		if golden.Update() {
+//			golden.Set(t, got)
+//		}
+//		require.Equal(t, golden.Get(t), got)
+//  }
+//
+// It is possible to have multiple golden files per test using `GetNamed` and
+// `SetNamed`. This is useful for cases where your unit under test produces
+// multiple pieces of output e.g stdout and stderr:
+//
+// 	func TestFooCommand(t *testing.T) {
+//		stdoutBuf := new(bytes.Buffer)
+//		stderrBuf := new(bytes.Buffer)
+//
+//		FooCommand(stdoutBuf, stderrBuf)
+//
+//		stdout := stdoutBuf.Bytes()
+//		stderr := stderrBuf.Bytes()
+//
+//		if golden.Update() {
+//			golden.SetNamed(t, "stdout", stdout)
+//			golden.SetNamed(t, "stderr", stderr)
+//		}
+//		require.Equal(t, golden.GetNamed(t, "stdout"), stdout)
+//		require.Equal(t, golden.GetNamed(t, "stderr"), stderr)
+//	}
+
+package golden
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func pathForFile(t *testing.T, name string) string {
+	pathComponents := []string{
+		"testdata",
+		t.Name(),
+	}
+
+	if name != "" {
+		pathComponents = append(pathComponents, name)
+	}
+
+	return filepath.Join(pathComponents...) + ".golden"
+}
+
+// ShouldSet provides a boolean value that indicates if your code should then
+// call `Set` or `SetNamed` to update the stored golden file value with new
+// data.
+func ShouldSet() bool {
+	env := os.Getenv("GOLDEN_UPDATE")
+	return env == "y" || env == "1"
+}
+
+// SetNamed writes the supplied data to a named golden file for the current
+// test.
+func SetNamed(t *testing.T, name string, data []byte) {
+	p := pathForFile(t, name)
+	dir := filepath.Dir(p)
+
+	err := os.MkdirAll(dir, 0o755)
+	require.NoError(t, err)
+
+	err = os.WriteFile(p, data, 0o644)
+	require.NoError(t, err)
+}
+
+// Set writes the supplied data to the golden file for the current test.
+func Set(t *testing.T, data []byte) {
+	SetNamed(t, "", data)
+}
+
+// GetNamed returns the contents of a named golden file for the current test. If
+// the specified golden file does not exist for the test, the test will be
+// failed.
+func GetNamed(t *testing.T, name string) []byte {
+	p := pathForFile(t, name)
+	data, err := os.ReadFile(p)
+	require.NoError(t, err)
+
+	return data
+}
+
+// Get returns the contents of the golden file for the current test. If there is
+// no golden file for the test, the test will be failed.
+func Get(t *testing.T) []byte {
+	return GetNamed(t, "")
+}

tool/tbot/config/config.go

@@ -95,6 +95,10 @@ type CLIConf struct {
 	// Clean is a flag that, if set, instructs `tbot init` to remove existing
 	// unexpected files.
 	Clean bool
+
+	// ConfigureOutput provides a path that the generated configuration file
+	// should be written to
+	ConfigureOutput string
 }
 
 // OnboardingConfig contains values only required on first connect.

tool/tbot/main.go

@@ -49,13 +49,13 @@ const (
 )
 
 func main() {
-	if err := Run(os.Args[1:]); err != nil {
+	if err := Run(os.Args[1:], os.Stdout); err != nil {
 		utils.FatalError(err)
 		trace.DebugReport(err)
 	}
 }
 
-func Run(args []string) error {
+func Run(args []string, stdout io.Writer) error {
 	var cf config.CLIConf
 	utils.InitLogger(utils.LoggingForDaemon, logrus.InfoLevel)
 
@@ -94,6 +94,7 @@ func Run(args []string) error {
 	configureCmd.Flag("oneshot", "If set, quit after the first renewal.").BoolVar(&cf.Oneshot)
 	configureCmd.Flag("renewal-interval", "Interval at which short-lived certificates are renewed; must be less than the certificate TTL.").DurationVar(&cf.RenewalInterval)
 	configureCmd.Flag("token", "A bot join token, if attempting to onboard a new bot; used on first connect.").Envar(tokenEnvVar).StringVar(&cf.Token)
+	configureCmd.Flag("output", "Path to write the generated configuration file to rather than write to stdout.").Short('o').StringVar(&cf.ConfigureOutput)
 
 	watchCmd := app.Command("watch", "Watch a destination directory for changes.").Hidden()
 
@@ -120,7 +121,7 @@ func Run(args []string) error {
 	case startCmd.FullCommand():
 		err = onStart(botConfig)
 	case configureCmd.FullCommand():
-		err = onConfigure(cf, os.Stdout)
+		err = onConfigure(cf, stdout)
 	case initCmd.FullCommand():
 		err = onInit(botConfig, &cf)
 	case watchCmd.FullCommand():
@@ -143,7 +144,7 @@ func onConfigure(
 	stdout io.Writer,
 ) error {
 	out := stdout
-	outPath := cf.ConfigPath
+	outPath := cf.ConfigureOutput
 	if outPath != "" {
 		f, err := os.Create(outPath)
 		if err != nil {

tool/tbot/main_test.go

@@ -1,42 +1,107 @@
+/*
+Copyright 2022 Gravitational, Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
 package main
 
 import (
 	"bytes"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
-	"github.com/gravitational/teleport/tool/tbot/config"
+	"github.com/gravitational/teleport/lib/utils/golden"
 	"github.com/stretchr/testify/require"
 )
 
-func Test_onConfigure(t *testing.T) {
+func TestRun_Configure(t *testing.T) {
 	t.Parallel()
 
-	cfg := &config.BotConfig{
-		AuthServer: "foo:bar",
+	// This is slightly rubbish, but due to the global nature of `botfs`,
+	// it's difficult to configure the default acl and symlink values to be
+	// the same across dev laptops and GCB.
+	// If we switch to a more dependency injected model for botfs, we can
+	// ensure that the test one returns the same value across operating systems.
+	normalizeOSDependentValues := func(data []byte) []byte {
+		str := string(data)
+		str = strings.ReplaceAll(
+			str, "symlinks: try-secure", "symlinks: secure",
+		)
+		str = strings.ReplaceAll(
+			str, `acls: "off"`, "acls: try",
+		)
+		return []byte(str)
 	}
-	// TODO: It would be nice to pull this out into a golden file
-	expect := "debug: false\nauth_server: foo:bar\ncertificate_ttl: 0s\nrenewal_interval: 0s\noneshot: false\n"
 
-	t.Run("file", func(t *testing.T) {
-		t.Parallel()
+	baseArgs := []string{"configure"}
+	tests := []struct {
+		name string
+		args []string
+	}{
+		{
+			name: "no parameters provided",
+			args: baseArgs,
+		},
+		{
+			name: "all parameters provided",
+			args: append(baseArgs, []string{
+				"-a", "example.com",
+				"--token", "xxyzz",
+				"--ca-pin", "sha256:capindata",
+				"--data-dir", "/custom/data/dir",
+				"--join-method", "token",
+				"--oneshot",
+				"--certificate-ttl", "42m",
+				"--renewal-interval", "21m",
+			}...),
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			t.Run("file", func(t *testing.T) {
+				t.Parallel()
 
-		path := filepath.Join(t.TempDir(), "config.yaml")
-		err := onConfigure(&config.BotConfig{}, path)
-		require.NoError(t, err)
+				path := filepath.Join(t.TempDir(), "config.yaml")
+				args := append(tt.args, []string{"-o", path}...)
+				err := Run(args, nil)
+				require.NoError(t, err)
 
-		data, err := os.ReadFile(path)
-		require.NoError(t, err)
-		require.Equal(t, expect, string(data))
-	})
+				data, err := os.ReadFile(path)
+				data = normalizeOSDependentValues(data)
+				require.NoError(t, err)
+				if golden.ShouldSet() {
+					golden.Set(t, data)
+				}
+				require.Equal(t, string(golden.Get(t)), string(data))
+			})
 
-	t.Run("stdout", func(t *testing.T) {
-		t.Parallel()
+			t.Run("stdout", func(t *testing.T) {
+				t.Parallel()
 
-		stdout := new(bytes.Buffer)
-		err := onConfigure(stdout, "")
-		require.NoError(t, err)
-		require.Equal(t, expect, stdout.String())
-	})
+				stdout := new(bytes.Buffer)
+				err := Run(tt.args, stdout)
+				require.NoError(t, err)
+				data := normalizeOSDependentValues(stdout.Bytes())
+				if golden.ShouldSet() {
+					golden.Set(t, data)
+				}
+				require.Equal(t, string(golden.Get(t)), string(data))
+			})
+		})
+	}
 }

tool/tbot/testdata/TestRun_Configure/all_parameters_provided/file.golden

@@ -0,0 +1,17 @@
+# tbot config file generated by `configure` command
+onboarding:
+  token: xxyzz
+  ca_path: ""
+  ca_pins:
+  - sha256:capindata
+  join_method: token
+storage:
+  directory:
+    path: /custom/data/dir
+    symlinks: secure
+    acls: try
+debug: false
+auth_server: example.com
+certificate_ttl: 42m0s
+renewal_interval: 21m0s
+oneshot: true

tool/tbot/testdata/TestRun_Configure/all_parameters_provided/stdout.golden

@@ -0,0 +1,17 @@
+# tbot config file generated by `configure` command
+onboarding:
+  token: xxyzz
+  ca_path: ""
+  ca_pins:
+  - sha256:capindata
+  join_method: token
+storage:
+  directory:
+    path: /custom/data/dir
+    symlinks: secure
+    acls: try
+debug: false
+auth_server: example.com
+certificate_ttl: 42m0s
+renewal_interval: 21m0s
+oneshot: true

tool/tbot/testdata/TestRun_Configure/no_parameters_provided/file.golden

@@ -0,0 +1,11 @@
+# tbot config file generated by `configure` command
+storage:
+  directory:
+    path: /var/lib/teleport/bot
+    symlinks: secure
+    acls: try
+debug: false
+auth_server: ""
+certificate_ttl: 1h0m0s
+renewal_interval: 20m0s
+oneshot: false

tool/tbot/testdata/TestRun_Configure/no_parameters_provided/stdout.golden

@@ -0,0 +1,11 @@
+# tbot config file generated by `configure` command
+storage:
+  directory:
+    path: /var/lib/teleport/bot
+    symlinks: secure
+    acls: try
+debug: false
+auth_server: ""
+certificate_ttl: 1h0m0s
+renewal_interval: 20m0s
+oneshot: false