[datadog_logs_metric][datadog_metric_metadata] Normalize invalid metr…

…ic name (#2433)

* add warning to invalid metric names

* Update datadog/internal/validators/validators.go

* use statefunc to normalize metric names

* fmt

datadog/internal/utils/utils.go

@@ -251,8 +251,6 @@ func DeleteKeyInMap(mapObject map[string]interface{}, keyList []string) {
 	} else if m, ok := mapObject[keyList[0]].(map[string]interface{}); ok {
 		DeleteKeyInMap(m, keyList[1:])
 	}
-
-	return
 }
 
 // GetStringSlice returns string slice for the given key if present, otherwise returns an empty slice
@@ -320,3 +318,79 @@ func StringSliceDifference(slice1, slice2 []string) []string {
 	}
 	return diff
 }
+
+// fast isAlpha for ascii
+func isAlpha(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z')
+}
+
+// fast isAlphaNumeric for ascii
+func isAlphaNum(b byte) bool {
+	return isAlpha(b) || (b >= '0' && b <= '9')
+}
+
+// ValidateMetricName ensures the given metric name length is in [0, MaxMetricLen] and
+// contains at least one alphabetic character whose index is returned
+func ValidateMetricName(name string) (int, error) {
+	var i int
+	if name == "" {
+		return 0, fmt.Errorf("metric name is empty")
+	}
+
+	// skip non-alphabetic characters
+	for ; i < len(name) && !isAlpha(name[i]); i++ {
+	}
+
+	// if there were no alphabetic characters it wasn't valid
+	if i == len(name) {
+		return 0, fmt.Errorf("metric name %s is invalid. it must contain at least one alphabetic character", name)
+	}
+
+	return i, nil
+}
+
+// NormMetricNameParse normalizes metric names with a parser instead of using
+// garbage-creating string replacement routines.
+func NormMetricNameParse(name string) string {
+	i, err := ValidateMetricName(name)
+	if err != nil {
+		return name
+	}
+
+	var ptr int
+	res := make([]byte, 0, len(name))
+
+	for ; i < len(name); i++ {
+		switch {
+		case isAlphaNum(name[i]):
+			res = append(res, name[i])
+			ptr++
+		case name[i] == '.':
+			// we skipped all non-alpha chars up front so we have seen at least one
+			switch res[ptr-1] {
+			// overwrite underscores that happen before periods
+			case '_':
+				res[ptr-1] = '.'
+			default:
+				res = append(res, '.')
+				ptr++
+			}
+		default:
+			// we skipped all non-alpha chars up front so we have seen at least one
+			switch res[ptr-1] {
+			// no double underscores, no underscores after periods
+			case '.', '_':
+			default:
+				res = append(res, '_')
+				ptr++
+			}
+		}
+	}
+
+	if res[ptr-1] == '_' {
+		res = res[:ptr-1]
+	}
+	// safe because res does not escape this function
+	return string(res)
+
+}

datadog/internal/utils/utils_test.go

@@ -187,3 +187,38 @@ func (r *mockResourceData) GetOk(key string) (interface{}, bool) {
 	v, ok := r.values[key]
 	return v, ok
 }
+
+var testMetricNames = map[string]string{
+	// bad metric names, need remapping
+	"test*&(*._-_Metrictastic*(*)(  wtf_who_doesthis??": "test.Metrictastic_wtf_who_doesthis",
+	"?does.this.work?":                        "does.this.work",
+	"5-2 arsenal over spurs":                  "arsenal_over_spurs",
+	"dd.crawler.amazon web services.run_time": "dd.crawler.amazon_web_services.run_time",
+
+	//  multiple metric names that normalize to the same thing
+	"multiple-norm-1": "multiple_norm_1",
+	"multiple_norm-1": "multiple_norm_1",
+
+	// for whatever reason, invalid characters x
+	"a$.b":            "a.b",
+	"a_.b":            "a.b",
+	"__init__.metric": "init.metric",
+	"a___..b":         "a..b",
+	"a_.":             "a.",
+}
+
+func TestNormMetricNameParse(t *testing.T) {
+	for src, target := range testMetricNames {
+		normed := NormMetricNameParse(src)
+		if normed != target {
+			t.Errorf("Expected tag '%s' normalized to '%s', got '%s' instead.", src, target, normed)
+			return
+		}
+		// double check that we're idempotent
+		again := NormMetricNameParse(normed)
+		if again != normed {
+			t.Errorf("Expected tag '%s' to be idempotent', got '%s' instead.", normed, again)
+			return
+		}
+	}
+}

datadog/resource_datadog_logs_metric.go

@@ -101,6 +101,9 @@ func resourceDatadogLogsMetric() *schema.Resource {
 					Required:    true,
 					ForceNew:    true,
 					Description: "The name of the log-based metric. This field can't be updated after creation.",
+					StateFunc: func(val any) string {
+						return utils.NormMetricNameParse(val.(string))
+					},
 				},
 			}
 		},

datadog/resource_datadog_metric_metadata.go

@@ -28,6 +28,9 @@ func resourceDatadogMetricMetadata() *schema.Resource {
 					Description: "The name of the metric.",
 					Type:        schema.TypeString,
 					Required:    true,
+					StateFunc: func(val any) string {
+						return utils.NormMetricNameParse(val.(string))
+					},
 				},
 				"type": {
 					Description: "Metric type such as `count`, `gauge`, or `rate`. Updating a metric of type `distribution` is not supported. If you would like to see the `distribution` type returned, contact [Datadog support](https://docs.datadoghq.com/help/).",