internal/appsec/config: default the time suffix of DD_APPSEC_WAF_TIME…

…OUT to us (#1195)

Co-authored-by: François Mazeau <francois.mazeau@datadoghq.com>

internal/appsec/config.go

@@ -11,6 +11,8 @@ import (
 	"os"
 	"strconv"
 	"time"
+	"unicode"
+	"unicode/utf8"
 
 	"gopkg.in/DataDog/dd-trace-go.v1/internal/log"
 )
@@ -69,9 +71,18 @@ func readWAFTimeoutConfig() (timeout time.Duration) {
 	if value == "" {
 		return
 	}
+
+	// Check if the value ends with a letter, which means the user has
+	// specified their own time duration unit(s) such as 1s200ms.
+	// Otherwise, default to microseconds.
+	if lastRune, _ := utf8.DecodeLastRuneInString(value); !unicode.IsLetter(lastRune) {
+		value += "us" // Add the default microsecond time-duration suffix
+	}
+
 	parsed, err := time.ParseDuration(value)
 	if err != nil {
 		logEnvVarParsingError(wafTimeoutEnvVar, value, err, timeout)
+		return
 	}
 	if parsed <= 0 {
 		logUnexpectedEnvVarValue(wafTimeoutEnvVar, parsed, "expecting a strictly positive duration", timeout)

internal/appsec/config_test.go

@@ -50,6 +50,23 @@ func TestConfig(t *testing.T) {
 			)
 		})
 
+		t.Run("parsable-default-microsecond", func(t *testing.T) {
+			restoreEnv := cleanEnv()
+			defer restoreEnv()
+			require.NoError(t, os.Setenv(wafTimeoutEnvVar, "1"))
+			cfg, err := newConfig()
+			require.NoError(t, err)
+			require.Equal(
+				t,
+				&config{
+					rules:          []byte(staticRecommendedRule),
+					wafTimeout:     1 * time.Microsecond,
+					traceRateLimit: defaultTraceRate,
+				},
+				cfg,
+			)
+		})
+
 		t.Run("not-parsable", func(t *testing.T) {
 			restoreEnv := cleanEnv()
 			defer restoreEnv()