kyverno/pkg/toggle/toggle.go

package toggle

import (
	"os"
	"strconv"
)

const (
	// autogen
	AutogenInternalsFlagName    = "autogenInternals"
	AutogenInternalsDescription = "Enables autogen internal policies. When this is 'true' policy rules should not be mutated."
	autogenInternalsEnvVar      = "FLAG_AUTOGEN_INTERNALS"
	defaultAutogenInternals     = true
	// protect managed resource
	ProtectManagedResourcesFlagName    = "protectManagedResources"
	ProtectManagedResourcesDescription = "Set the flag to 'true', to enable managed resources protection."
	protectManagedResourcesEnvVar      = "FLAG_PROTECT_MANAGED_RESOURCES"
	defaultProtectManagedResources     = false
)

var (
	AutogenInternals        = newToggle(defaultAutogenInternals, autogenInternalsEnvVar)
	ProtectManagedResources = newToggle(defaultProtectManagedResources, protectManagedResourcesEnvVar)
)

type Toggle interface {
	Enabled() bool
	Parse(string) error
}

type toggle struct {
	value        *bool
	defaultValue bool
	envVar       string
}

func newToggle(defaultValue bool, envVar string) *toggle {
	return &toggle{
		defaultValue: defaultValue,
		envVar:       envVar,
	}
}

func (t *toggle) Parse(in string) error {
	if value, err := getBool(in); err != nil {
		return err
	} else {
		t.value = value
		return nil
	}
}

func (t *toggle) Enabled() bool {
	if t.value != nil {
		return *t.value
	}
	if value, err := getBool(os.Getenv(t.envVar)); err == nil && value != nil {
		return *value
	}
	return t.defaultValue
}

func getBool(in string) (*bool, error) {
	if in == "" {
		return nil, nil
	}
	value, err := strconv.ParseBool(in)
	if err != nil {
		return nil, err
	}
	return &value, nil
}