internal/secret: add FlagVar
The standard flag package offers both String and StringVar API flavors,
and each one is sometimes more convenient than the other (depending on
the situation). Offer both Flag and FlagVar variants in secret as well.
Also reword our documentation slightly for consistency with flag's own.
Change-Id: I2996c1df25c62fa6e01fbf36e6d952a8f5337811
Reviewed-on: https://go-review.googlesource.com/c/build/+/411574
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Run-TryBot: Dmitri Shuralyov <dmitshur@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>
diff --git a/internal/secret/flag.go b/internal/secret/flag.go
index af97241..bb72ac2 100644
--- a/internal/secret/flag.go
+++ b/internal/secret/flag.go
@@ -25,16 +25,26 @@
const secretSuffix = "[ specify `secret:[project name/]<secret name>` to read from Secret Manager ]"
-// Flag declares a string flag on set that will be resolved using r.
-func (r *FlagResolver) Flag(set *flag.FlagSet, name string, usage string) *string {
- var value string
+// Flag defines a string flag on set that will be resolved using r.
+// The return value is the address of a string variable that stores the value of the flag.
+func (r *FlagResolver) Flag(set *flag.FlagSet, name, usage string) *string {
+ p := new(string)
+ r.FlagVar(set, p, name, usage)
+ return p
+}
+
+// FlagVar defines a string flag on set that will be resolved using r.
+// The argument p points to a string variable in which to store the value of the flag.
+func (r *FlagResolver) FlagVar(set *flag.FlagSet, p *string, name, usage string) {
suffixedUsage := usage + "\n" + secretSuffix
set.Func(name, suffixedUsage, func(flagValue string) error {
- var err error
- value, err = r.resolveSecret(flagValue)
- return err
+ value, err := r.resolveSecret(flagValue)
+ if err != nil {
+ return err
+ }
+ *p = value
+ return nil
})
- return &value
}
func (r *FlagResolver) resolveSecret(flagValue string) (string, error) {
@@ -62,9 +72,9 @@
return string(result.Payload.GetData()), nil
}
-// JSONVarFlag declares a flag on set that behaves like Flag and then
+// JSONVarFlag defines a flag on set that behaves like Flag and then
// json.Unmarshals the resulting string into value.
-func (r *FlagResolver) JSONVarFlag(set *flag.FlagSet, value interface{}, name string, usage string) {
+func (r *FlagResolver) JSONVarFlag(set *flag.FlagSet, value interface{}, name, usage string) {
suffixedUsage := usage + "\n" + fmt.Sprintf("A JSON representation of a %T.", value) + "\n" + secretSuffix
set.Func(name, suffixedUsage, func(flagValue string) error {
stringValue, err := r.resolveSecret(flagValue)
@@ -78,16 +88,23 @@
// DefaultResolver is the FlagResolver used by the convenience functions.
var DefaultResolver FlagResolver
-// Flag declares a string flag on flag.CommandLine that supports Secret Manager
+// Flag defines a string flag on flag.CommandLine that supports Secret Manager
// resolution for values like "secret:<secret name>". InitFlagSupport must be
// called before flag.Parse.
-func Flag(name string, usage string) *string {
+func Flag(name, usage string) *string {
return DefaultResolver.Flag(flag.CommandLine, name, usage)
}
-// JSONVarFlag declares a flag on flag.CommandLine that behaves like Flag
+// FlagVar defines a string flag on flag.CommandLine that supports Secret Manager
+// resolution for values like "secret:<secret name>". InitFlagSupport must be
+// called before flag.Parse.
+func FlagVar(p *string, name, usage string) {
+ DefaultResolver.FlagVar(flag.CommandLine, p, name, usage)
+}
+
+// JSONVarFlag defines a flag on flag.CommandLine that behaves like Flag
// and then json.Unmarshals the resulting string into value.
-func JSONVarFlag(value interface{}, name string, usage string) {
+func JSONVarFlag(value interface{}, name, usage string) {
DefaultResolver.JSONVarFlag(flag.CommandLine, value, name, usage)
}
