Allow validating config.Duration type (letsencrypt#7564)

Fixes letsencrypt#7505

cmd/shell.go

@@ -34,6 +34,7 @@ import (
 	semconv "go.opentelemetry.io/otel/semconv/v1.25.0"
 	"google.golang.org/grpc/grpclog"
 
+	"github.com/letsencrypt/boulder/config"
 	"github.com/letsencrypt/boulder/core"
 	blog "github.com/letsencrypt/boulder/log"
 	"github.com/letsencrypt/boulder/strictyaml"
@@ -455,6 +456,9 @@ func ValidateJSONConfig(cv *ConfigValidator, in io.Reader) error {
 		}
 	}
 
+	// Register custom types for use with existing validation tags.
+	validate.RegisterCustomTypeFunc(config.DurationCustomTypeFunc, config.Duration{})
+
 	err := decodeJSONStrict(in, cv.Config)
 	if err != nil {
 		return err
@@ -497,6 +501,9 @@ func ValidateYAMLConfig(cv *ConfigValidator, in io.Reader) error {
 		}
 	}
 
+	// Register custom types for use with existing validation tags.
+	validate.RegisterCustomTypeFunc(config.DurationCustomTypeFunc, config.Duration{})
+
 	inBytes, err := io.ReadAll(in)
 	if err != nil {
 		return err

cmd/shell_test.go

@@ -11,10 +11,12 @@ import (
 	"testing"
 	"time"
 
+	"github.com/prometheus/client_golang/prometheus"
+
+	"github.com/letsencrypt/boulder/config"
 	"github.com/letsencrypt/boulder/core"
 	blog "github.com/letsencrypt/boulder/log"
 	"github.com/letsencrypt/boulder/test"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
 var (
@@ -196,9 +198,11 @@ func loadConfigFile(t *testing.T, path string) *os.File {
 
 func TestFailedConfigValidation(t *testing.T) {
 	type FooConfig struct {
-		VitalValue       string `yaml:"vitalValue" validate:"required"`
-		VoluntarilyVoid  string `yaml:"voluntarilyVoid"`
-		VisciouslyVetted string `yaml:"visciouslyVetted" validate:"omitempty,endswith=baz"`
+		VitalValue       string          `yaml:"vitalValue" validate:"required"`
+		VoluntarilyVoid  string          `yaml:"voluntarilyVoid"`
+		VisciouslyVetted string          `yaml:"visciouslyVetted" validate:"omitempty,endswith=baz"`
+		VolatileVagary   config.Duration `yaml:"volatileVagary" validate:"required,lte=120s"`
+		VernalVeil       config.Duration `yaml:"vernalVeil" validate:"required"`
 	}
 
 	// Violates 'endswith' tag JSON.
@@ -228,6 +232,34 @@ func TestFailedConfigValidation(t *testing.T) {
 	err = ValidateYAMLConfig(&ConfigValidator{&FooConfig{}, nil}, cf)
 	test.AssertError(t, err, "Expected validation error")
 	test.AssertContains(t, err.Error(), "'required'")
+
+	// Violates 'lte' tag JSON for config.Duration type.
+	cf = loadConfigFile(t, "testdata/3_configDuration_too_darn_big.json")
+	defer cf.Close()
+	err = ValidateJSONConfig(&ConfigValidator{&FooConfig{}, nil}, cf)
+	test.AssertError(t, err, "Expected validation error")
+	test.AssertContains(t, err.Error(), "'lte'")
+
+	// Violates 'lte' tag JSON for config.Duration type.
+	cf = loadConfigFile(t, "testdata/3_configDuration_too_darn_big.json")
+	defer cf.Close()
+	err = ValidateJSONConfig(&ConfigValidator{&FooConfig{}, nil}, cf)
+	test.AssertError(t, err, "Expected validation error")
+	test.AssertContains(t, err.Error(), "'lte'")
+
+	// Incorrect value for the config.Duration type.
+	cf = loadConfigFile(t, "testdata/4_incorrect_data_for_type.json")
+	defer cf.Close()
+	err = ValidateJSONConfig(&ConfigValidator{&FooConfig{}, nil}, cf)
+	test.AssertError(t, err, "Expected error")
+	test.AssertContains(t, err.Error(), "missing unit in duration")
+
+	// Incorrect value for the config.Duration type.
+	cf = loadConfigFile(t, "testdata/4_incorrect_data_for_type.yaml")
+	defer cf.Close()
+	err = ValidateYAMLConfig(&ConfigValidator{&FooConfig{}, nil}, cf)
+	test.AssertError(t, err, "Expected error")
+	test.AssertContains(t, err.Error(), "missing unit in duration")
 }
 
 func TestFailExit(t *testing.T) {

cmd/testdata/3_configDuration_too_darn_big.json

@@ -0,0 +1,6 @@
+{
+    "vitalValue": "Gotcha",
+    "voluntarilyVoid": "Not used",
+    "visciouslyVetted": "Whateverbaz",
+    "volatileVagary": "121s"
+}

cmd/testdata/4_incorrect_data_for_type.json

@@ -0,0 +1,7 @@
+{
+    "vitalValue": "Gotcha",
+    "voluntarilyVoid": "Not used",
+    "visciouslyVetted": "Whateverbaz",
+    "volatileVagary": "120s",
+    "vernalVeil": "60"
+}

cmd/testdata/4_incorrect_data_for_type.yaml

@@ -0,0 +1,5 @@
+vitalValue: "Gotcha"
+voluntarilyVoid: "Not used"
+visciouslyVetted: "Whateverbaz"
+volatileVagary: "120s"
+vernalVeil: "60"

config/duration.go

@@ -3,15 +3,27 @@ package config
 import (
 	"encoding/json"
 	"errors"
+	"reflect"
 	"time"
 )
 
-// Duration is just an alias for time.Duration that allows
-// serialization to YAML as well as JSON.
+// Duration is custom type embedding a time.Duration which allows defining
+// methods such as serialization to YAML or JSON.
 type Duration struct {
 	time.Duration `validate:"required"`
 }
 
+// DurationCustomTypeFunc enables registration of our custom config.Duration
+// type as a time.Duration and performing validation on the configured value
+// using the standard suite of validation functions.
+func DurationCustomTypeFunc(field reflect.Value) interface{} {
+	if c, ok := field.Interface().(Duration); ok {
+		return c.Duration
+	}
+
+	return reflect.Invalid
+}
+
 // ErrDurationMustBeString is returned when a non-string value is
 // presented to be deserialized as a ConfigDuration
 var ErrDurationMustBeString = errors.New("cannot JSON unmarshal something other than a string into a ConfigDuration")