Added GDPR to the app config (prebid#505)

* Added GDPR to the app config.

* Removed some accidental changes.

* Added some unit tests.

* Fixed a vet error.

config/config.go

@@ -27,13 +27,32 @@ type Configuration struct {
 	MaxRequestSize       int64              `mapstructure:"max_request_size"`
 	Analytics            Analytics          `mapstructure:"analytics"`
 	AMPTimeoutAdjustment int64              `mapstructure:"amp_timeout_adjustment_ms"`
+	GDPR                 GDPR               `mapstructure:"gdpr"`
 }
 
 func (cfg *Configuration) validate() error {
 	if cfg.MaxRequestSize < 0 {
 		return fmt.Errorf("cfg.max_request_size must be a positive number. Got  %d", cfg.MaxRequestSize)
 	}
-	return cfg.StoredRequests.validate()
+
+	if err := cfg.StoredRequests.validate(); err != nil {
+		return err
+	}
+
+	return cfg.GDPR.validate()
+}
+
+type GDPR struct {
+	HostVendorID        int  `mapstructure:"host_vendor_id"`
+	UsersyncIfAmbiguous bool `mapstructure:"usersync_if_ambiguous"`
+}
+
+func (cfg *GDPR) validate() error {
+	if cfg.HostVendorID < 0 || cfg.HostVendorID > 0xffff {
+		return fmt.Errorf("host_vendor_id must be in the range [0, %d]. Got %d", 0xffff, cfg.HostVendorID)
+	}
+
+	return nil
 }
 
 type Analytics struct {

config/config_test.go

@@ -37,6 +37,9 @@ func TestDefaults(t *testing.T) {
 }
 
 var fullConfig = []byte(`
+gdpr:
+  host_vendor_id: 15
+  usersync_if_ambiguous: true
 host_cookie:
   cookie_name: userid
   family: prebid
@@ -95,6 +98,13 @@ func cmpInts(t *testing.T, key string, a int, b int) {
 	}
 }
 
+func cmpBools(t *testing.T, key string, a bool, b bool) {
+	t.Helper()
+	if a != b {
+		t.Errorf("%s: %t != %t", key, a, b)
+	}
+}
+
 func TestFullConfig(t *testing.T) {
 	v := newViperWithDefaults()
 	v.SetConfigType("yaml")
@@ -118,6 +128,8 @@ func TestFullConfig(t *testing.T) {
 	cmpStrings(t, "cache.scheme", cfg.CacheURL.Scheme, "http")
 	cmpStrings(t, "cache.host", cfg.CacheURL.Host, "prebidcache.net")
 	cmpStrings(t, "cache.query", cfg.CacheURL.Query, "uuid=%PBS_CACHE_UUID%")
+	cmpInts(t, "gdpr.host_vendor_id", cfg.GDPR.HostVendorID, 15)
+	cmpBools(t, "gdpr.usersync_if_ambiguous", cfg.GDPR.UsersyncIfAmbiguous, true)
 	cmpStrings(t, "recaptcha_secret", cfg.RecaptchaSecret, "asdfasdfasdfasdf")
 	cmpStrings(t, "metrics.influxdb.host", cfg.Metrics.Influxdb.Host, "upstream:8232")
 	cmpStrings(t, "metrics.influxdb.database", cfg.Metrics.Influxdb.Database, "metricsdb")
@@ -180,3 +192,27 @@ func TestNegativeRequestSize(t *testing.T) {
 		t.Error("cfg.max_request_size should prevent negative values, but it doesn't")
 	}
 }
+
+func TestNegativeVendorID(t *testing.T) {
+	cfg := Configuration{
+		GDPR: GDPR{
+			HostVendorID: -1,
+		},
+	}
+
+	if err := cfg.validate(); err == nil {
+		t.Error("cfg.gdpr.host_vendor_id should prevent negative values, but it doesn't")
+	}
+}
+
+func TestOverflowedVendorID(t *testing.T) {
+	cfg := Configuration{
+		GDPR: GDPR{
+			HostVendorID: (0xffff) + 1,
+		},
+	}
+
+	if err := cfg.validate(); err == nil {
+		t.Errorf("cfg.gdpr.host_vendor_id should prevent values over %d, but it doesn't", 0xffff)
+	}
+}