X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/51bb28e3e62563fa0921f003b8d11ce8740f3a68..f41534fcdfa95c282a04d64158f8a7d850637768:/lib/cmd/cmd.go

diff --git a/lib/cmd/cmd.go b/lib/cmd/cmd.go
index f33354a24b..63d7576b4c 100644
--- a/lib/cmd/cmd.go
+++ b/lib/cmd/cmd.go
@@ -2,8 +2,8 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
-// package cmd defines a RunFunc type, representing a process that can
-// be invoked from a command line.
+// Package cmd helps define reusable functions that can be exposed as
+// [subcommands of] command line programs.
 package cmd
 
 import (
@@ -11,45 +11,97 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"path/filepath"
+	"regexp"
+	"runtime"
 	"sort"
 	"strings"
+
+	"github.com/sirupsen/logrus"
 )
 
-// A RunFunc runs a command with the given args, and returns an exit
-// code.
-type RunFunc func(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int
+type Handler interface {
+	RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int
+}
+
+type HandlerFunc func(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int
+
+func (f HandlerFunc) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
+	return f(prog, args, stdin, stdout, stderr)
+}
+
+// Version is a Handler that prints the package version (set at build
+// time using -ldflags) and Go runtime version to stdout, and returns
+// 0.
+var Version versionCommand
+
+var version = "dev"
 
-// Multi returns a RunFunc that looks up its first argument in m, and
-// invokes the resulting RunFunc with the remaining args.
+type versionCommand struct{}
+
+func (versionCommand) String() string {
+	return fmt.Sprintf("%s (%s)", version, runtime.Version())
+}
+
+func (versionCommand) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
+	prog = regexp.MustCompile(` -*version$`).ReplaceAllLiteralString(prog, "")
+	fmt.Fprintf(stdout, "%s %s (%s)\n", prog, version, runtime.Version())
+	return 0
+}
+
+// Multi is a Handler that looks up its first argument in a map (after
+// stripping any "arvados-" or "crunch-" prefix), and invokes the
+// resulting Handler with the remaining args.
 //
 // Example:
 //
-//     os.Exit(Multi(map[string]RunFunc{
-//             "foobar": func(prog string, args []string) int {
+//     os.Exit(Multi(map[string]Handler{
+//             "foobar": HandlerFunc(func(prog string, args []string) int {
 //                     fmt.Println(args[0])
 //                     return 2
-//             },
+//             }),
 //     })("/usr/bin/multi", []string{"foobar", "baz"}))
 //
 // ...prints "baz" and exits 2.
-func Multi(m map[string]RunFunc) RunFunc {
-	return func(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
-		if len(args) < 1 {
-			fmt.Fprintf(stderr, "usage: %s command [args]\n", prog)
-			multiUsage(stderr, m)
-			return 2
-		}
-		if cmd, ok := m[args[0]]; !ok {
-			fmt.Fprintf(stderr, "unrecognized command %q\n", args[0])
-			multiUsage(stderr, m)
-			return 2
-		} else {
-			return cmd(prog+" "+args[0], args[1:], stdin, stdout, stderr)
-		}
+type Multi map[string]Handler
+
+func (m Multi) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
+	_, basename := filepath.Split(prog)
+	if i := strings.Index(basename, "~"); i >= 0 {
+		// drop "~anything" suffix (arvados-dispatch-cloud's
+		// DeployRunnerBinary feature relies on this)
+		basename = basename[:i]
+	}
+	cmd, ok := m[basename]
+	if !ok {
+		// "controller" command exists, and binary is named "arvados-controller"
+		cmd, ok = m[strings.TrimPrefix(basename, "arvados-")]
+	}
+	if !ok {
+		// "dispatch-slurm" command exists, and binary is named "crunch-dispatch-slurm"
+		cmd, ok = m[strings.TrimPrefix(basename, "crunch-")]
+	}
+	if ok {
+		return cmd.RunCommand(prog, args, stdin, stdout, stderr)
+	} else if len(args) < 1 {
+		fmt.Fprintf(stderr, "usage: %s command [args]\n", prog)
+		m.Usage(stderr)
+		return 2
+	} else if cmd, ok = m[args[0]]; ok {
+		return cmd.RunCommand(prog+" "+args[0], args[1:], stdin, stdout, stderr)
+	} else {
+		fmt.Fprintf(stderr, "%s: unrecognized command %q\n", prog, args[0])
+		m.Usage(stderr)
+		return 2
 	}
 }
 
-func multiUsage(stderr io.Writer, m map[string]RunFunc) {
+func (m Multi) Usage(stderr io.Writer) {
+	fmt.Fprintf(stderr, "\nAvailable commands:\n")
+	m.listSubcommands(stderr, "")
+}
+
+func (m Multi) listSubcommands(out io.Writer, prefix string) {
 	var subcommands []string
 	for sc := range m {
 		if strings.HasPrefix(sc, "-") {
@@ -61,17 +113,23 @@ func multiUsage(stderr io.Writer, m map[string]RunFunc) {
 		subcommands = append(subcommands, sc)
 	}
 	sort.Strings(subcommands)
-	fmt.Fprintf(stderr, "\nAvailable commands:\n")
 	for _, sc := range subcommands {
-		fmt.Fprintf(stderr, "    %s\n", sc)
+		switch cmd := m[sc].(type) {
+		case Multi:
+			cmd.listSubcommands(out, prefix+sc+" ")
+		default:
+			fmt.Fprintf(out, "    %s%s\n", prefix, sc)
+		}
 	}
 }
 
 type FlagSet interface {
 	Init(string, flag.ErrorHandling)
+	Args() []string
 	NArg() int
 	Parse([]string) error
 	SetOutput(io.Writer)
+	PrintDefaults()
 }
 
 // SubcommandToFront silently parses args using flagset, and returns a
@@ -97,3 +155,9 @@ func SubcommandToFront(args []string, flagset FlagSet) []string {
 	copy(newargs[flagargs+1:], args[flagargs+1:])
 	return newargs
 }
+
+type NoPrefixFormatter struct{}
+
+func (NoPrefixFormatter) Format(entry *logrus.Entry) ([]byte, error) {
+	return []byte(entry.Message + "\n"), nil
+}