open-vault/command/main.go
Alexander Scheel 3eaa4b0d75
Write explicit -help output to stdout (#17308)
* Write explicit -help output to stdout

Per the consensus of most programs, and mirroring the GNU Coding
Standards for CLI design, when users request -help explicitly via the
CLI, this should be written to stdout to allow paging of output. stderr
is fine when an invalid usage triggers the help text however.

In our case, mitchellh/cli helpfully adds a HelpWriter that we
previously set to stderr explicitly. This writer is only called to print
user-requested help text; it is not called on error cases (e.g., bad
usage triggering additional help text to the user).

Thus it should safely be settable to stdout, enabling pagers without
additional redirects.

Notably, we do have to set ErrorWriter as it defaults to initializing to
the value of HelpWriter, which we want to set to stdout now, which is
less useful.

See also: https://www.gnu.org/prep/standards/html_node/_002d_002dhelp.html
Resolves: #17004

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

* Add changelog

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>
2022-09-26 12:15:48 -04:00

361 lines
8.3 KiB
Go

package command
import (
"bufio"
"bytes"
"fmt"
"io"
"os"
"sort"
"strconv"
"strings"
"text/tabwriter"
"github.com/fatih/color"
"github.com/hashicorp/vault/api"
"github.com/hashicorp/vault/command/token"
colorable "github.com/mattn/go-colorable"
"github.com/mitchellh/cli"
)
type VaultUI struct {
cli.Ui
format string
detailed bool
}
const (
globalFlagOutputCurlString = "output-curl-string"
globalFlagOutputPolicy = "output-policy"
globalFlagFormat = "format"
globalFlagDetailed = "detailed"
)
var globalFlags = []string{
globalFlagOutputCurlString, globalFlagOutputPolicy, globalFlagFormat, globalFlagDetailed,
}
// setupEnv parses args and may replace them and sets some env vars to known
// values based on format options
func setupEnv(args []string) (retArgs []string, format string, detailed bool, outputCurlString bool, outputPolicy bool) {
var err error
var nextArgFormat bool
var haveDetailed bool
for _, arg := range args {
if nextArgFormat {
nextArgFormat = false
format = arg
continue
}
if arg == "--" {
break
}
if len(args) == 1 && (arg == "-v" || arg == "-version" || arg == "--version") {
args = []string{"version"}
break
}
if isGlobalFlag(arg, globalFlagOutputCurlString) {
outputCurlString = true
continue
}
if isGlobalFlag(arg, globalFlagOutputPolicy) {
outputPolicy = true
continue
}
// Parse a given flag here, which overrides the env var
if isGlobalFlagWithValue(arg, globalFlagFormat) {
format = getGlobalFlagValue(arg)
}
// For backwards compat, it could be specified without an equal sign
if isGlobalFlag(arg, globalFlagFormat) {
nextArgFormat = true
}
// Parse a given flag here, which overrides the env var
if isGlobalFlagWithValue(arg, globalFlagDetailed) {
detailed, err = strconv.ParseBool(getGlobalFlagValue(globalFlagDetailed))
if err != nil {
detailed = false
}
haveDetailed = true
}
// For backwards compat, it could be specified without an equal sign to enable
// detailed output.
if isGlobalFlag(arg, globalFlagDetailed) {
detailed = true
haveDetailed = true
}
}
envVaultFormat := os.Getenv(EnvVaultFormat)
// If we did not parse a value, fetch the env var
if format == "" && envVaultFormat != "" {
format = envVaultFormat
}
// Lowercase for consistency
format = strings.ToLower(format)
if format == "" {
format = "table"
}
envVaultDetailed := os.Getenv(EnvVaultDetailed)
// If we did not parse a value, fetch the env var
if !haveDetailed && envVaultDetailed != "" {
detailed, err = strconv.ParseBool(envVaultDetailed)
if err != nil {
detailed = false
}
}
return args, format, detailed, outputCurlString, outputPolicy
}
func isGlobalFlag(arg string, flag string) bool {
return arg == "-"+flag || arg == "--"+flag
}
func isGlobalFlagWithValue(arg string, flag string) bool {
return strings.HasPrefix(arg, "--"+flag+"=") || strings.HasPrefix(arg, "-"+flag+"=")
}
func getGlobalFlagValue(arg string) string {
_, value, _ := strings.Cut(arg, "=")
return value
}
type RunOptions struct {
TokenHelper token.TokenHelper
Stdout io.Writer
Stderr io.Writer
Address string
Client *api.Client
}
func Run(args []string) int {
return RunCustom(args, nil)
}
// RunCustom allows passing in a base command template to pass to other
// commands. Currently, this is only used for setting a custom token helper.
func RunCustom(args []string, runOpts *RunOptions) int {
if runOpts == nil {
runOpts = &RunOptions{}
}
var format string
var detailed bool
var outputCurlString bool
var outputPolicy bool
args, format, detailed, outputCurlString, outputPolicy = setupEnv(args)
// Don't use color if disabled
useColor := true
if os.Getenv(EnvVaultCLINoColor) != "" || color.NoColor {
useColor = false
}
if runOpts.Stdout == nil {
runOpts.Stdout = os.Stdout
}
if runOpts.Stderr == nil {
runOpts.Stderr = os.Stderr
}
// Only use colored UI if stdout is a tty, and not disabled
if useColor && format == "table" {
if f, ok := runOpts.Stdout.(*os.File); ok {
runOpts.Stdout = colorable.NewColorable(f)
}
if f, ok := runOpts.Stderr.(*os.File); ok {
runOpts.Stderr = colorable.NewColorable(f)
}
} else {
runOpts.Stdout = colorable.NewNonColorable(runOpts.Stdout)
runOpts.Stderr = colorable.NewNonColorable(runOpts.Stderr)
}
uiErrWriter := runOpts.Stderr
if outputCurlString || outputPolicy {
uiErrWriter = &bytes.Buffer{}
}
ui := &VaultUI{
Ui: &cli.ColoredUi{
ErrorColor: cli.UiColorRed,
WarnColor: cli.UiColorYellow,
Ui: &cli.BasicUi{
Reader: bufio.NewReader(os.Stdin),
Writer: runOpts.Stdout,
ErrorWriter: uiErrWriter,
},
},
format: format,
detailed: detailed,
}
serverCmdUi := &VaultUI{
Ui: &cli.ColoredUi{
ErrorColor: cli.UiColorRed,
WarnColor: cli.UiColorYellow,
Ui: &cli.BasicUi{
Reader: bufio.NewReader(os.Stdin),
Writer: runOpts.Stdout,
},
},
format: format,
}
if _, ok := Formatters[format]; !ok {
ui.Error(fmt.Sprintf("Invalid output format: %s", format))
return 1
}
initCommands(ui, serverCmdUi, runOpts)
hiddenCommands := []string{"version"}
cli := &cli.CLI{
Name: "vault",
Args: args,
Commands: Commands,
HelpFunc: groupedHelpFunc(
cli.BasicHelpFunc("vault"),
),
HelpWriter: runOpts.Stdout,
ErrorWriter: runOpts.Stderr,
HiddenCommands: hiddenCommands,
Autocomplete: true,
AutocompleteNoDefaultFlags: true,
}
exitCode, err := cli.Run()
if outputCurlString {
return generateCurlString(exitCode, runOpts, uiErrWriter.(*bytes.Buffer))
} else if outputPolicy {
return generatePolicy(exitCode, runOpts, uiErrWriter.(*bytes.Buffer))
} else if err != nil {
fmt.Fprintf(runOpts.Stderr, "Error executing CLI: %s\n", err.Error())
return 1
}
return exitCode
}
var commonCommands = []string{
"read",
"write",
"delete",
"list",
"login",
"agent",
"server",
"status",
"unwrap",
}
func groupedHelpFunc(f cli.HelpFunc) cli.HelpFunc {
return func(commands map[string]cli.CommandFactory) string {
var b bytes.Buffer
tw := tabwriter.NewWriter(&b, 0, 2, 6, ' ', 0)
fmt.Fprintf(tw, "Usage: vault <command> [args]\n\n")
fmt.Fprintf(tw, "Common commands:\n")
for _, v := range commonCommands {
printCommand(tw, v, commands[v])
}
otherCommands := make([]string, 0, len(commands))
for k := range commands {
found := false
for _, v := range commonCommands {
if k == v {
found = true
break
}
}
if !found {
otherCommands = append(otherCommands, k)
}
}
sort.Strings(otherCommands)
fmt.Fprintf(tw, "\n")
fmt.Fprintf(tw, "Other commands:\n")
for _, v := range otherCommands {
printCommand(tw, v, commands[v])
}
tw.Flush()
return strings.TrimSpace(b.String())
}
}
func printCommand(w io.Writer, name string, cmdFn cli.CommandFactory) {
cmd, err := cmdFn()
if err != nil {
panic(fmt.Sprintf("failed to load %q command: %s", name, err))
}
fmt.Fprintf(w, " %s\t%s\n", name, cmd.Synopsis())
}
func generateCurlString(exitCode int, runOpts *RunOptions, preParsingErrBuf *bytes.Buffer) int {
if exitCode == 0 {
fmt.Fprint(runOpts.Stderr, "Could not generate cURL command")
return 1
}
if api.LastOutputStringError == nil {
if exitCode == 127 {
// Usage, just pass it through
return exitCode
}
runOpts.Stderr.Write(preParsingErrBuf.Bytes())
runOpts.Stderr.Write([]byte("Unable to generate cURL string from command\n"))
return exitCode
}
cs, err := api.LastOutputStringError.CurlString()
if err != nil {
runOpts.Stderr.Write([]byte(fmt.Sprintf("Error creating request string: %s\n", err)))
return 1
}
runOpts.Stdout.Write([]byte(fmt.Sprintf("%s\n", cs)))
return 0
}
func generatePolicy(exitCode int, runOpts *RunOptions, preParsingErrBuf *bytes.Buffer) int {
if exitCode == 0 {
fmt.Fprint(runOpts.Stderr, "Could not generate policy")
return 1
}
if api.LastOutputPolicyError == nil {
if exitCode == 127 {
// Usage, just pass it through
return exitCode
}
runOpts.Stderr.Write(preParsingErrBuf.Bytes())
runOpts.Stderr.Write([]byte("Unable to generate policy from command\n"))
return exitCode
}
hcl, err := api.LastOutputPolicyError.HCLString()
if err != nil {
runOpts.Stderr.Write([]byte(fmt.Sprintf("Error assembling policy HCL: %s\n", err)))
return 1
}
runOpts.Stdout.Write([]byte(fmt.Sprintf("%s\n", hcl)))
return 0
}