TUN-3715: Only read config file once, right before invoking the command

Author: ipostelnik

CHANGES.md

@@ -1,5 +1,24 @@
 **Experimental**: This is a new format for release notes. The format and availability is subject to change.
 
+## UNRELEASED
+
+### Backward Incompatible Changes
+
+- none
+
+### New Features
+
+- none
+
+### Improvements
+
+- nonw
+
+### Bug Fixes
+
+- Don't look for configuration file in default paths when `--config FILE` flag is present after `tunnel` subcommand.
+
+
 ## 2021.3.0
 
 ### New Features

cmd/cloudflared/access/cmd.go

@@ -84,7 +84,7 @@ func Commands() []*cli.Command {
 			Subcommands: []*cli.Command{
 				{
 					Name:   "login",
-					Action: cliutil.ErrorHandler(login),
+					Action: cliutil.Action(login),
 					Usage:  "login <url of access application>",
 					Description: `The login subcommand initiates an authentication flow with your identity provider.
 					The subcommand will launch a browser. For headless systems, a url is provided.
@@ -100,7 +100,7 @@ func Commands() []*cli.Command {
 				},
 				{
 					Name:   "curl",
-					Action: cliutil.ErrorHandler(curl),
+					Action: cliutil.Action(curl),
 					Usage:  "curl [--allow-request, -ar] <url> [<curl args>...]",
 					Description: `The curl subcommand wraps curl and automatically injects the JWT into a cf-access-token
 					header when using curl to reach an application behind Access.`,
@@ -109,7 +109,7 @@ func Commands() []*cli.Command {
 				},
 				{
 					Name:        "token",
-					Action:      cliutil.ErrorHandler(generateToken),
+					Action:      cliutil.Action(generateToken),
 					Usage:       "token -app=<url of access application>",
 					ArgsUsage:   "url of Access application",
 					Description: `The token subcommand produces a JWT which can be used to authenticate requests.`,
@@ -121,7 +121,7 @@ func Commands() []*cli.Command {
 				},
 				{
 					Name:        "tcp",
-					Action:      cliutil.ErrorHandler(ssh),
+					Action:      cliutil.Action(ssh),
 					Aliases:     []string{"rdp", "ssh", "smb"},
 					Usage:       "",
 					ArgsUsage:   "",
@@ -175,7 +175,7 @@ func Commands() []*cli.Command {
 				},
 				{
 					Name:        "ssh-config",
-					Action:      cliutil.ErrorHandler(sshConfig),
+					Action:      cliutil.Action(sshConfig),
 					Usage:       "",
 					Description: `Prints an example configuration ~/.ssh/config`,
 					Flags: []cli.Flag{
@@ -191,7 +191,7 @@ func Commands() []*cli.Command {
 				},
 				{
 					Name:        "ssh-gen",
-					Action:      cliutil.ErrorHandler(sshGen),
+					Action:      cliutil.Action(sshGen),
 					Usage:       "",
 					Description: `Generates a short lived certificate for given hostname`,
 					Flags: []cli.Flag{

cmd/cloudflared/cliutil/deprecated.go

@@ -9,12 +9,12 @@ import (
 func RemovedCommand(name string) *cli.Command {
 	return &cli.Command{
 		Name: name,
-		Action: ErrorHandler(func(context *cli.Context) error {
+		Action: func(context *cli.Context) error {
 			return cli.Exit(
 				fmt.Sprintf("%s command is no longer supported by cloudflared. Consult Argo Tunnel documentation for possible alternative solutions.", name),
 				-1,
 			)
-		}),
+		},
 		Description: fmt.Sprintf("%s is deprecated", name),
 		Hidden: true,
 	}

cmd/cloudflared/cliutil/errors.go

@@ -2,6 +2,7 @@ package cliutil
 
 import (
 	"fmt"
+
 	"github.com/urfave/cli/v2"
 )
 
@@ -21,7 +22,7 @@ func UsageError(format string, args ...interface{}) error {
 }
 
 // Ensures exit with error code if actionFunc returns an error
-func ErrorHandler(actionFunc cli.ActionFunc) cli.ActionFunc {
+func WithErrorHandler(actionFunc cli.ActionFunc) cli.ActionFunc {
 	return func(ctx *cli.Context) error {
 		err := actionFunc(ctx)
 		if err != nil {

cmd/cloudflared/cliutil/handler.go

@@ -0,0 +1,53 @@
+package cliutil
+
+import (
+	"github.com/urfave/cli/v2"
+	"github.com/urfave/cli/v2/altsrc"
+
+	"github.com/cloudflare/cloudflared/config"
+	"github.com/cloudflare/cloudflared/logger"
+)
+
+func Action(actionFunc cli.ActionFunc) cli.ActionFunc {
+	return WithErrorHandler(func(c *cli.Context) error {
+		if err := setFlagsFromConfigFile(c); err != nil {
+			return err
+		}
+		return actionFunc(c)
+	})
+}
+
+func setFlagsFromConfigFile(c *cli.Context) error {
+	const errorExitCode = 1
+	log := logger.CreateLoggerFromContext(c, logger.EnableTerminalLog)
+	inputSource, err := config.ReadConfigFile(c, log)
+	if err != nil {
+		if err == config.ErrNoConfigFile {
+			return nil
+		}
+		return cli.Exit(err, errorExitCode)
+	}
+
+	if err := applyConfig(c, inputSource); err != nil {
+		return cli.Exit(err, errorExitCode)
+	}
+	return nil
+}
+
+func applyConfig(c *cli.Context, inputSource altsrc.InputSourceContext) error {
+	for _, context := range c.Lineage() {
+		if context.Command == nil {
+			// we've reached the placeholder root context not associated with the app
+			break
+		}
+		targetFlags := context.Command.Flags
+		if context.Command.Name == "" {
+			// commands that define child subcommands are executed as if they were an app
+			targetFlags = c.App.Flags
+		}
+		if err := altsrc.ApplyInputSourceValues(context, inputSource, targetFlags); err != nil {
+			return err
+		}
+	}
+	return nil
+}

cmd/cloudflared/linux_service.go

@@ -24,7 +24,7 @@ func runApp(app *cli.App, graceShutdownC chan struct{}) {
 			{
 				Name:   "install",
 				Usage:  "Install Argo Tunnel as a system service",
-				Action: cliutil.ErrorHandler(installLinuxService),
+				Action: cliutil.Action(installLinuxService),
 				Flags: []cli.Flag{
 					&cli.BoolFlag{
 						Name:  "legacy",
@@ -35,7 +35,7 @@ func runApp(app *cli.App, graceShutdownC chan struct{}) {
 			{
 				Name:   "uninstall",
 				Usage:  "Uninstall the Argo Tunnel service",
-				Action: cliutil.ErrorHandler(uninstallLinuxService),
+				Action: cliutil.Action(uninstallLinuxService),
 			},
 		},
 	})

cmd/cloudflared/macos_service.go

@@ -25,12 +25,12 @@ func runApp(app *cli.App, graceShutdownC chan struct{}) {
 			{
 				Name:   "install",
 				Usage:  "Install Argo Tunnel as an user launch agent",
-				Action: cliutil.ErrorHandler(installLaunchd),
+				Action: cliutil.Action(installLaunchd),
 			},
 			{
 				Name:   "uninstall",
 				Usage:  "Uninstall the Argo Tunnel launch agent",
-				Action: cliutil.ErrorHandler(uninstallLaunchd),
+				Action: cliutil.Action(uninstallLaunchd),
 			},
 		},
 	})

cmd/cloudflared/main.go

@@ -77,7 +77,6 @@ func main() {
 	See https://developers.cloudflare.com/argo-tunnel/ for more in-depth documentation.`
 	app.Flags = flags()
 	app.Action = action(graceShutdownC)
-	app.Before = tunnel.SetFlagsFromConfigFile
 	app.Commands = commands(cli.ShowVersion)
 
 	tunnel.Init(Version, graceShutdownC) // we need this to support the tunnel sub command...
@@ -90,7 +89,7 @@ func commands(version func(c *cli.Context)) []*cli.Command {
 	cmds := []*cli.Command{
 		{
 			Name:   "update",
-			Action: cliutil.ErrorHandler(updater.Update),
+			Action: cliutil.Action(updater.Update),
 			Usage:  "Update the agent if a new version exists",
 			Flags: []cli.Flag{
 				&cli.BoolFlag{
@@ -145,7 +144,7 @@ func isEmptyInvocation(c *cli.Context) bool {
 }
 
 func action(graceShutdownC chan struct{}) cli.ActionFunc {
-	return cliutil.ErrorHandler(func(c *cli.Context) (err error) {
+	return cliutil.Action(func(c *cli.Context) (err error) {
 		if isEmptyInvocation(c) {
 			return handleServiceMode(c, graceShutdownC)
 		}

cmd/cloudflared/proxydns/cmd.go

@@ -17,7 +17,8 @@ import (
 func Command(hidden bool) *cli.Command {
 	return &cli.Command{
 		Name:   "proxy-dns",
-		Action: cliutil.ErrorHandler(Run),
+		Action: cliutil.Action(Run),
+
 		Usage:  "Run a DNS over HTTPS proxy server.",
 		Flags: []cli.Flag{
 			&cli.StringFlag{

cmd/cloudflared/tunnel/cmd.go

@@ -7,7 +7,6 @@ import (
 	"io/ioutil"
 	"net/url"
 	"os"
-	"reflect"
 	"runtime/trace"
 	"strings"
 	"sync"
@@ -120,8 +119,7 @@ func Commands() []*cli.Command {
 func buildTunnelCommand(subcommands []*cli.Command) *cli.Command {
 	return &cli.Command{
 		Name:      "tunnel",
-		Action:    cliutil.ErrorHandler(TunnelCommand),
-		Before:    SetFlagsFromConfigFile,
+		Action:    cliutil.Action(TunnelCommand),
 		Category:  "Tunnel",
 		Usage:     "Make a locally-running web service accessible over the internet using Argo Tunnel.",
 		ArgsUsage: " ",
@@ -369,26 +367,6 @@ func StartServer(
 	return waitToShutdown(&wg, cancel, errC, graceShutdownC, c.Duration("grace-period"), log)
 }
 
-func SetFlagsFromConfigFile(c *cli.Context) error {
-	const exitCode = 1
-	log := logger.CreateLoggerFromContext(c, logger.EnableTerminalLog)
-	inputSource, err := config.ReadConfigFile(c, log)
-	if err != nil {
-		if err == config.ErrNoConfigFile {
-			return nil
-		}
-		return cli.Exit(err, exitCode)
-	}
-	targetFlags := c.Command.Flags
-	if c.Command.Name == "" {
-		targetFlags = c.App.Flags
-	}
-	if err := altsrc.ApplyInputSourceValues(c, inputSource, targetFlags); err != nil {
-		return cli.Exit(err, exitCode)
-	}
-	return nil
-}
-
 func waitToShutdown(wg *sync.WaitGroup,
 	cancelServerContext func(),
 	errC <-chan error,
@@ -477,33 +455,6 @@ func addPortIfMissing(uri *url.URL, port int) string {
 	return fmt.Sprintf("%s:%d", uri.Hostname(), port)
 }
 
-// appendFlags will append extra flags to a slice of flags.
-//
-// The cli package will panic if two flags exist with the same name,
-// so if extraFlags contains a flag that was already defined, modify the
-// original flags to use the extra version.
-func appendFlags(flags []cli.Flag, extraFlags ...cli.Flag) []cli.Flag {
-	for _, extra := range extraFlags {
-		var found bool
-
-		// Check if an extra flag overrides an existing flag.
-		for i, flag := range flags {
-			if reflect.DeepEqual(extra.Names(), flag.Names()) {
-				flags[i] = extra
-				found = true
-				break
-			}
-		}
-
-		// Append the extra flag if it has nothing to override.
-		if !found {
-			flags = append(flags, extra)
-		}
-	}
-
-	return flags
-}
-
 func tunnelFlags(shouldHide bool) []cli.Flag {
 	flags := configureCloudflaredFlags(shouldHide)
 	flags = append(flags, configureProxyFlags(shouldHide)...)
@@ -652,6 +603,7 @@ func tunnelFlags(shouldHide bool) []cli.Flag {
 			Aliases: []string{"n"},
 			EnvVars: []string{"TUNNEL_NAME"},
 			Usage:   "Stable name to identify the tunnel. Using this flag will create, route and run a tunnel. For production usage, execute each command separately",
+			Hidden:  shouldHide,
 		}),
 		altsrc.NewBoolFlag(&cli.BoolFlag{
 			Name:   uiFlag,