feat(cli): implement personality for application name-agnostic help manuals

cmd/version.go

@@ -24,3 +24,9 @@ func MockVersion(version string) (restore func()) {
 	Version = version
 	return func() { Version = old }
 }
+
+// ProgramName represents the name of the application binary.
+var ProgramName string = "pebble"
+
+// DisplayName represents the user-facing name of the application.
+var DisplayName string = "Pebble"

internals/cli/cli.go

@@ -33,6 +33,7 @@ import (
 	"golang.org/x/crypto/ssh/terminal"
 
 	"github.com/canonical/pebble/client"
+	"github.com/canonical/pebble/cmd"
 	"github.com/canonical/pebble/internals/logger"
 )
 
@@ -165,8 +166,9 @@ func Parser(cli *client.Client) *flags.Parser {
 
 	flagOpts := flags.Options(flags.PassDoubleDash)
 	parser := flags.NewParser(&defaultOpts, flagOpts)
-	parser.ShortDescription = "Tool to interact with pebble"
-	parser.LongDescription = longPebbleDescription
+	parser.Command.Name = cmd.ProgramName
+	parser.ShortDescription = "System and service manager"
+	parser.LongDescription = applyPersonality(longPebbleDescription)
 
 	// Add --help like what go-flags would do for us, but hidden
 	addHelp(parser)
@@ -192,7 +194,7 @@ func Parser(cli *client.Client) *flags.Parser {
 		} else {
 			target = parser.Command
 		}
-		cmd, err := target.AddCommand(c.Name, c.Summary, strings.TrimSpace(c.Description), obj)
+		cmd, err := target.AddCommand(c.Name, applyPersonality(c.Summary), applyPersonality(strings.TrimSpace(c.Description)), obj)
 		if err != nil {
 			logger.Panicf("internal error: cannot add command %q: %v", c.Name, err)
 		}
@@ -203,9 +205,9 @@ func Parser(cli *client.Client) *flags.Parser {
 		positionalHelp := map[string]string{}
 		for specifier, help := range c.ArgsHelp {
 			if flagRegexp.MatchString(specifier) {
-				flagHelp[specifier] = help
+				flagHelp[specifier] = applyPersonality(help)
 			} else if positionalRegexp.MatchString(specifier) {
-				positionalHelp[specifier] = help
+				positionalHelp[specifier] = applyPersonality(help)
 			} else {
 				logger.Panicf("internal error: invalid help specifier from %q: %q", c.Name, specifier)
 			}
@@ -219,10 +221,10 @@ func Parser(cli *client.Client) *flags.Parser {
 		for _, opt := range opts {
 			if description, ok := flagHelp["--"+opt.LongName]; ok {
 				lintDesc(c.Name, opt.LongName, description, opt.Description)
-				opt.Description = description
+				opt.Description = applyPersonality(description)
 			} else if description, ok := flagHelp["-"+string(opt.ShortName)]; ok {
 				lintDesc(c.Name, string(opt.ShortName), description, opt.Description)
-				opt.Description = description
+				opt.Description = applyPersonality(description)
 			} else if !opt.Hidden {
 				logger.Panicf("internal error: %q missing description for %q", c.Name, opt)
 			}
@@ -240,6 +242,11 @@ func Parser(cli *client.Client) *flags.Parser {
 	return parser
 }
 
+func applyPersonality(s string) string {
+	r := strings.NewReplacer("{{.ProgramName}}", cmd.ProgramName, "{{.DisplayName}}", cmd.DisplayName)
+	return r.Replace(s)
+}
+
 var (
 	isStdinTTY  = terminal.IsTerminal(0)
 	isStdoutTTY = terminal.IsTerminal(1)
@@ -271,7 +278,7 @@ func Run() error {
 		}
 	}()
 
-	logger.SetLogger(logger.New(os.Stderr, "[pebble] "))
+	logger.SetLogger(logger.New(os.Stderr, fmt.Sprintf("[%s] ", cmd.ProgramName)))
 
 	_, clientConfig.Socket = getEnvPaths()
 
@@ -293,11 +300,11 @@ func Run() error {
 				return nil
 			case flags.ErrUnknownCommand:
 				sub := os.Args[1]
-				sug := "pebble help"
+				sug := cmd.ProgramName + " help"
 				if len(xtra) > 0 {
 					sub = xtra[0]
 					if x := parser.Command.Active; x != nil && x.Name != "help" {
-						sug = "pebble help " + x.Name
+						sug = cmd.ProgramName + " help " + x.Name
 					}
 				}
 				return fmt.Errorf("unknown command %q, see '%s'", sub, sug)
@@ -341,7 +348,7 @@ func errorToMessage(e error) (normalMessage string, err error) {
 		}
 	case client.ErrorKindSystemRestart:
 		isError = false
-		msg = "pebble is about to reboot the system"
+		msg = fmt.Sprintf("%s is about to reboot the system", cmd.DisplayName)
 	case client.ErrorKindNoDefaultServices:
 		msg = "no default services"
 	default:

internals/cli/cmd_changes.go

@@ -22,6 +22,7 @@ import (
 	"github.com/canonical/go-flags"
 
 	"github.com/canonical/pebble/client"
+	"github.com/canonical/pebble/cmd"
 )
 
 const cmdChangesSummary = "List system changes"
@@ -97,7 +98,7 @@ func (c *cmdChanges) Execute(args []string) error {
 	}
 
 	if allDigits(c.Positional.Service) {
-		return fmt.Errorf(`'pebble changes' command expects a service name, try 'pebble tasks %s'`, c.Positional.Service)
+		return fmt.Errorf(`'%s changes' command expects a service name, try '%s tasks %s'`, cmd.ProgramName, cmd.ProgramName, c.Positional.Service)
 	}
 
 	if c.Positional.Service == "everything" {

internals/cli/cmd_changes_test.go

@@ -177,7 +177,7 @@ func (s *PebbleSuite) TestChangeSimpleRebooting(c *check.C) {
 
 	_, err := cli.Parser(cli.Client()).ParseArgs([]string{"tasks", "42"})
 	c.Assert(err, check.IsNil)
-	c.Check(s.Stderr(), check.Equals, "WARNING: pebble is about to reboot the system\n")
+	c.Check(s.Stderr(), check.Equals, "WARNING: Pebble is about to reboot the system\n")
 }
 
 func (s *PebbleSuite) TestChangeSimpleUnknownMaintenance(c *check.C) {

internals/cli/cmd_enter.go

@@ -25,7 +25,7 @@ import (
 
 const cmdEnterSummary = "Run subcommand under a container environment"
 const cmdEnterDescription = `
-The enter command facilitates the use of Pebble as an entrypoint for containers.
+The enter command facilitates the use of {{.DisplayName}} as an entrypoint for containers.
 When used without a subcommand it mimics the behavior of the run command
 alone, while if used with a subcommand it runs that subcommand in the most
 appropriate environment taking into account its purpose.
@@ -178,7 +178,7 @@ func (cmd *cmdEnter) Execute(args []string) error {
 	case runStop = <-runReadyCh:
 	case runPanic := <-runResultCh:
 		if runPanic == nil {
-			panic("internal error: pebble daemon stopped early")
+			panic("internal error: daemon stopped early")
 		}
 		panic(runPanic)
 	}

internals/cli/cmd_exec.go

@@ -39,7 +39,7 @@ stderr are output locally.
 To avoid confusion, exec options may be separated from the command and its
 arguments using "--", for example:
 
-pebble exec --timeout 10s -- echo -n foo bar
+{{.ProgramName}} exec --timeout 10s -- echo -n foo bar
 `
 
 type cmdExec struct {

internals/cli/cmd_help.go

@@ -23,6 +23,8 @@ import (
 	"unicode/utf8"
 
 	"github.com/canonical/go-flags"
+
+	cmdpkg "github.com/canonical/pebble/cmd"
 )
 
 const cmdHelpSummary = "Show help about a command"
@@ -103,17 +105,24 @@ func (cmd *cmdHelp) setParser(parser *flags.Parser) {
 // - duplicated TP lines that break older groff (e.g. 14.04), lp:1814767
 type manfixer struct {
 	bytes.Buffer
-	done bool
+	done        bool
+	programName string
 }
 
 func (w *manfixer) Write(buf []byte) (int, error) {
 	if !w.done {
 		w.done = true
-		if bytes.HasPrefix(buf, []byte(".TH pebble 1 ")) {
-			// io.Writer.Write must not modify the buffer, even temporarily
-			n, _ := w.Buffer.Write(buf[:9])
+		// Find the .TH <program name> prefix.
+		prefix := ".TH " + w.programName + " "
+		if bytes.HasPrefix(buf, []byte(prefix)) {
+			// io.Writer.Write must not modify the buffer, even temporarily.
+			// Write all characters up to the prefix.
+			n, _ := w.Buffer.Write(buf[:len(prefix)])
+			// Do not write the character after the prefix (originally, '1'),
+			// and write an '8' instead, for fixing up the man section.
 			w.Buffer.Write([]byte{'8'})
-			m, err := w.Buffer.Write(buf[10:])
+			// Write everything after the original '1' character.
+			m, err := w.Buffer.Write(buf[1+len(prefix):])
 			return n + m + 1, err
 		}
 	}
@@ -134,7 +143,7 @@ func (cmd cmdHelp) Execute(args []string) error {
 	if cmd.Manpage {
 		// you shouldn't try to to combine --man with --all nor a
 		// subcommand, but --man is hidden so no real need to check.
-		out := &manfixer{}
+		out := &manfixer{programName: cmd.parser.Name}
 		cmd.parser.WriteManPage(out)
 		out.flush()
 		return nil
@@ -151,9 +160,9 @@ func (cmd cmdHelp) Execute(args []string) error {
 	for _, subname := range cmd.Positional.Subs {
 		subcmd = subcmd.Find(subname)
 		if subcmd == nil {
-			sug := "pebble help"
+			sug := cmdpkg.ProgramName + " help"
 			if x := cmd.parser.Command.Active; x != nil && x.Name != "help" {
-				sug = "pebble help " + x.Name
+				sug = cmdpkg.ProgramName + " help " + x.Name
 			}
 			return fmt.Errorf("unknown command %q, see '%s'.", subname, sug)
 		}
@@ -175,7 +184,7 @@ type HelpCategory struct {
 // HelpCategories helps us by grouping commands
 var HelpCategories = []HelpCategory{{
 	Label:       "Run",
-	Description: "run pebble",
+	Description: "run the service manager",
 	Commands:    []string{"run", "help", "version"},
 }, {
 	Label:       "Plan",
@@ -205,35 +214,35 @@ var HelpCategories = []HelpCategory{{
 
 var (
 	longPebbleDescription = strings.TrimSpace(`
-Pebble lets you control services and perform management actions on
+{{.DisplayName}} lets you control services and perform management actions on
 the system that is running them.
 `)
-	pebbleUsage               = "Usage: pebble <command> [<options>...]"
+	pebbleUsage               = "Usage: {{.ProgramName}} <command> [<options>...]"
 	pebbleHelpCategoriesIntro = "Commands can be classified as follows:"
 	pebbleHelpAllFooter       = "Set the PEBBLE environment variable to override the configuration directory \n" +
 		"(which defaults to " + defaultPebbleDir + "). Set PEBBLE_SOCKET to override \n" +
 		"the unix socket used for the API (defaults to $PEBBLE/.pebble.socket).\n" +
 		"\n" +
-		"For more information about a command, run 'pebble help <command>'."
-	pebbleHelpFooter = "For a short summary of all commands, run 'pebble help --all'."
+		"For more information about a command, run '{{.ProgramName}} help <command>'."
+	pebbleHelpFooter = "For a short summary of all commands, run '{{.ProgramName}} help --all'."
 )
 
 func printHelpHeader() {
-	fmt.Fprintln(Stdout, longPebbleDescription)
+	fmt.Fprintln(Stdout, applyPersonality(longPebbleDescription))
 	fmt.Fprintln(Stdout)
-	fmt.Fprintln(Stdout, pebbleUsage)
+	fmt.Fprintln(Stdout, applyPersonality(pebbleUsage))
 	fmt.Fprintln(Stdout)
-	fmt.Fprintln(Stdout, pebbleHelpCategoriesIntro)
+	fmt.Fprintln(Stdout, applyPersonality(pebbleHelpCategoriesIntro))
 }
 
 func printHelpAllFooter() {
 	fmt.Fprintln(Stdout)
-	fmt.Fprintln(Stdout, pebbleHelpAllFooter)
+	fmt.Fprintln(Stdout, applyPersonality(pebbleHelpAllFooter))
 }
 
 func printHelpFooter() {
 	printHelpAllFooter()
-	fmt.Fprintln(Stdout, pebbleHelpFooter)
+	fmt.Fprintln(Stdout, applyPersonality(pebbleHelpFooter))
 }
 
 // this is called when the Execute returns a flags.Error with ErrCommandRequired

internals/cli/cmd_help_test.go

@@ -56,7 +56,7 @@ func (s *PebbleSuite) TestHelpMan(c *C) {
 
 	err := cli.RunMain()
 	c.Assert(err, Equals, nil)
-	c.Check(s.Stdout(), Matches, `(?s)\.TH.*\.SH NAME.*pebble \\- Tool to interact with pebble.*`)
+	c.Check(s.Stdout(), Matches, `(?s)\.TH pebble 8.*\.SH NAME.*pebble \\- System and service manager.*`)
 	c.Check(s.Stderr(), Equals, "")
 }
 

internals/cli/cmd_notices.go

@@ -29,7 +29,7 @@ const cmdNoticesSummary = "List notices"
 const cmdNoticesDescription = `
 The notices command lists notices not yet acknowledged, ordered by the
 last-repeated time (oldest first). After it runs, the notices that were shown
-may then be acknowledged by running 'pebble okay'. When a notice repeats, it
+may then be acknowledged by running '{{.ProgramName}} okay'. When a notice repeats, it
 needs to be acknowledged again.
 `
 

internals/cli/cmd_okay.go

@@ -20,14 +20,15 @@ import (
 	"github.com/canonical/go-flags"
 
 	"github.com/canonical/pebble/client"
+	cmdpkg "github.com/canonical/pebble/cmd"
 )
 
 const cmdOkaySummary = "Acknowledge notices and warnings"
 const cmdOkayDescription = `
 The okay command acknowledges warnings and notices that have been previously
-listed using 'pebble warnings' or 'pebble notices', so that they are omitted
+listed using '{{.ProgramName}} warnings' or '{{.ProgramName}} notices', so that they are omitted
 from future runs of either command. When a notice or warning is repeated, it
-will again show up until the next 'pebble okay'.
+will again show up until the next '{{.ProgramName}} okay'.
 `
 
 type cmdOkay struct {
@@ -85,10 +86,10 @@ func (cmd *cmdOkay) Execute(args []string) error {
 	}
 
 	if cmd.Warnings && !okayedWarnings {
-		return fmt.Errorf("no warnings have been listed; try 'pebble warnings'")
+		return fmt.Errorf("no warnings have been listed; try '%s warnings'", cmdpkg.ProgramName)
 	}
 	if !cmd.Warnings && !okayedNotices && !okayedWarnings {
-		return fmt.Errorf("no notices or warnings have been listed; try 'pebble notices' or 'pebble warnings'")
+		return fmt.Errorf("no notices or warnings have been listed; try '%s notices' or '%s warnings'", cmdpkg.ProgramName, cmdpkg.ProgramName)
 	}
 
 	return nil

internals/cli/cmd_plan.go

@@ -22,7 +22,7 @@ import (
 
 var cmdPlanSummary = "Show the plan with layers combined"
 var cmdPlanDescription = `
-The plan command prints out the effective configuration of pebble in YAML
+The plan command prints out the effective configuration of {{.DisplayName}} in YAML
 format. Layers are combined according to the override rules defined in them.
 `
 

internals/cli/cmd_run.go

@@ -31,16 +31,16 @@ import (
 	"github.com/canonical/pebble/internals/systemd"
 )
 
-const cmdRunSummary = "Run the pebble environment"
+const cmdRunSummary = "Run the service manager environment"
 const cmdRunDescription = `
-The run command starts pebble and runs the configured environment.
+The run command starts {{.DisplayName}} and runs the configured environment.
 
 Additional arguments may be provided to the service command with the --args option, which
-must be terminated with ";" unless there are no further Pebble options.  These arguments
+must be terminated with ";" unless there are no further program options.  These arguments
 are appended to the end of the service command, and replace any default arguments defined
 in the service plan. For example:
 
-    $ pebble run --args myservice --port 8080 \; --hold
+{{.ProgramName}} run --args myservice --port 8080 \; --hold
 `
 
 type sharedRunEnterOpts struct {
@@ -52,7 +52,7 @@ type sharedRunEnterOpts struct {
 }
 
 var sharedRunEnterArgsHelp = map[string]string{
-	"--create-dirs": "Create pebble directory on startup if it doesn't exist",
+	"--create-dirs": "Create {{.DisplayName}} directory on startup if it doesn't exist",
 	"--hold":        "Do not start default services automatically",
 	"--http":        `Start HTTP API listening on this address (e.g., ":4000")`,
 	"--verbose":     "Log all output from services to stdout",
@@ -98,7 +98,7 @@ func (rcmd *cmdRun) run(ready chan<- func()) {
 			// This exit code must be in system'd SuccessExitStatus.
 			panic(&exitStatus{42})
 		}
-		fmt.Fprintf(os.Stderr, "cannot run pebble: %v\n", err)
+		fmt.Fprintf(os.Stderr, "cannot run daemon: %v\n", err)
 		panic(&exitStatus{1})
 	}
 }

internals/cli/cmd_signal.go

@@ -28,7 +28,7 @@ const cmdSignalDescription = `
 The signal command sends a signal to one or more running services. The signal
 name must be uppercase, for example:
 
-pebble signal HUP mysql nginx
+{{.ProgramName}} signal HUP mysql nginx
 `
 
 type cmdSignal struct {