flagvalue

Documentation

Overview

Package flagvalue provides custom pflag.Value implementations for common flag types.

Index

• type SimpleValue
• type Value
  • func Counter(val int, p *int) Value
  • func Duration(val time.Duration, p *time.Duration) Value
  • func Enum[T comparable](allowed []T, val T, p *T) Value
  • func Simple[T SimpleValue](val T, p *T) Value
  • func SimpleMap[K, V SimpleValue](val map[K]V, p *map[K]V) Value
  • func SimpleSlice[T SimpleValue](val []T, p *[]T) Value

Examples

• Duration
• Enum
• Simple
• Simple (Boolean)
• SimpleMap
• SimpleSlice

Types

type SimpleValue

type SimpleValue interface {
	constraints.Float | constraints.Integer | ~string | ~bool |
		*string | *bool
}

SimpleValue is a constraint that includes all the types supported by the Simple flag value.

type Value

type Value = pflag.Value

Value is the interface to the dynamic value stored in a flag.

func Counter

func Counter(val int, p *int) Value

Counter returns a pflags.Value that sets the value at p with the default val or the value provided via a flag.

func Duration

func Duration(val time.Duration, p *time.Duration) Value

Duration returns a pflag.Value that sets the duration at p with the default val or the value provided via a flag.

Example

package main

import (
	"time"

	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var sleep time.Duration
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:     "wait",
		Usage:    "wait specifies the time to sleep before taking an action",
		DefValue: "5s",
		Value:    flagvalue.Duration(5*time.Second, &sleep),
	})

	time.Sleep(sleep)

	// ... Take an action
}

func Enum

func Enum[T comparable](allowed []T, val T, p *T) Value

Enum returns a pflags.Value that sets the value at p with the default val or the value provided via a flag. The provided value must be in the allowed list or an error is returned.

Example

package main

import (
	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var logLevel string
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:     "log-level",
		Usage:    "log-level specifies the verbosity to log with.",
		DefValue: "warn",
		Value:    flagvalue.Enum([]string{"trace", "debug", "info", "warn", "error"}, "warn", &logLevel),
	})

	// Setup logger
	// logger := hclog.Default().SetLevel(hclog.LevelFromString(logLevel))
	// logger.Warn("we are using flags!")
}

func Simple

func Simple[T SimpleValue](val T, p *T) Value

Simple returns a pflags.Value that sets the value at p with the default val or the value provided via a flag.

If the type of the value is a boolean, set the NoOptDefVal to "true", on the Flag. Otherwise the flag will have to have a value set to be parsed. As an example if the boolean flag had the name "force" and NoOptDefVal is not set, the flag will have to be set as --force=true.

Example

package main

import (
	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var projectID string
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:  "project",
		Usage: "project specifies the HCP Project ID to use.",
		Value: flagvalue.Simple[string]("", &projectID),
	})
}

Example (Boolean)

package main

import (
	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var force bool
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:      "force",
		Shorthand: "f",
		Usage:     "force force deletes without confirmation.",
		Value:     flagvalue.Simple[bool](false, &force),

		// Critical to set for boolean values. Otherwise -f, --force will not
		// set force to true. Instead the flag parsing will error expecting a
		// value to be set for the flag.
		NoOptDefVal: "true",
	})
}

func SimpleMap

func SimpleMap[K, V SimpleValue](val map[K]V, p *map[K]V) Value

SimpleMap returns a pflags.Value that sets the map at p with the default val or the value(s) provided via a flag.

Example

package main

import (
	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var headers map[string]string
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:  "headers",
		Usage: "headers is a set of headers to send with the request. May be specified multiple times in the form of KEY=VALUE.",
		Value: flagvalue.SimpleMap(nil, &headers),
	})

	// Make the request
}

func SimpleSlice

func SimpleSlice[T SimpleValue](val []T, p *[]T) Value

SimpleSlice returns a pflags.Value that sets the slice at p with the default val or the value(s) provided via a flag.

Example

package main

import (
	"github.com/spf13/pflag"

	"github.com/hashicorp/tfctl-cli/internal/pkg/flagvalue"
)

func main() {
	var secrets []string
	f := pflag.NewFlagSet("example", pflag.ContinueOnError)
	f.AddFlag(&pflag.Flag{
		Name:  "secret",
		Usage: "secret is a secret to read. Multiple values may be specified.",
		Value: flagvalue.SimpleSlice[string]([]string{}, &secrets),
	})

	// Fetch the secrets
}