Add DNSConfig.String() method

Resolves #1612 (comment)

cmd/options.go

@@ -91,7 +91,7 @@ func optionFlagSet() *pflag.FlagSet {
 	flags.StringSlice("tag", nil, "add a `tag` to be applied to all samples, as `[name]=[value]`")
 	flags.String("console-output", "", "redirects the console logging to the provided output file")
 	flags.Bool("discard-response-bodies", false, "Read but don't process or save HTTP response bodies")
-	flags.String("dns", lib.DefaultDNSConfigText, "DNS configuration. Possible ttl values are: 'inf' "+
+	flags.String("dns", lib.DefaultDNSConfig().String(), "DNS configuration. Possible ttl values are: 'inf' "+
 		"for a persistent cache, '0' to disable the cache,\nor a positive duration, e.g. '1s', '1m', etc. "+
 		"Milliseconds are assumed if no unit is provided.\n"+
 		"Possible values for the strategy to use to select a single IP are: 'first', 'random' or 'round-robin'.\n")

lib/options.go

@@ -27,6 +27,7 @@ import (
 	"net"
 	"reflect"
 	"strconv"
+	"strings"
 
 	"github.com/kubernetes/helm/pkg/strvals"
 	"github.com/pkg/errors"
@@ -67,15 +68,20 @@ const (
 	DNSRandom
 )
 
-const DefaultDNSConfigText = "ttl=inf,strategy=first"
-
 func DefaultDNSConfig() DNSConfig {
 	return DNSConfig{
 		TTL:      null.NewString("inf", false),
 		Strategy: NullDNSStrategy{DNSFirst, false},
 	}
 }
 
+func (c DNSConfig) String() string {
+	out := make([]string, 0, 2)
+	out = append(out, fmt.Sprintf("ttl=%s", c.TTL.String))
+	out = append(out, fmt.Sprintf("strategy=%s", c.Strategy.String()))
+	return strings.Join(out, ",")
+}
+
 func (c DNSConfig) MarshalJSON() ([]byte, error) {
 	var strat string
 	if c.Strategy.IsADNSStrategy() {
@@ -99,7 +105,7 @@ func (c *DNSConfig) UnmarshalJSON(data []byte) error {
 }
 
 func (c *DNSConfig) UnmarshalText(text []byte) error {
-	if string(text) == DefaultDNSConfigText {
+	if string(text) == DefaultDNSConfig().String() {
 		*c = DefaultDNSConfig()
 		return nil
 	}