Rename "label" to "attribute" in expression matcher DSL

internal/coreinternal/processor/filterexpr/matcher.go

@@ -27,7 +27,13 @@ type Matcher struct {
 
 type env struct {
 	MetricName string
-	// TODO: replace this with GetLabel func(key string) (string,bool)
+
+	// TODO: replace this with GetAttribute func(key string) (string,bool)
+	HasAttribute func(key string) bool
+	Attribute    func(key string) string
+
+	// HasLabel and Label are aliases for HasAttribute and Attribute, kept for
+	// backwards compatibility. These are deprecated and will be removed in the future.
 	HasLabel func(key string) bool
 	Label    func(key string) string
 }
@@ -101,17 +107,21 @@ func (m *Matcher) matchEnv(metricName string, attributes pdata.AttributeMap) (bo
 }
 
 func createEnv(metricName string, attributes pdata.AttributeMap) env {
-	return env{
+	e := env{
 		MetricName: metricName,
-		HasLabel: func(key string) bool {
+		HasAttribute: func(key string) bool {
 			_, ok := attributes.Get(key)
 			return ok
 		},
-		Label: func(key string) string {
+		Attribute: func(key string) string {
 			v, _ := attributes.Get(key)
 			return v.StringVal()
 		},
 	}
+	// HasLabel and Label are aliases for HasAttribute and Attribute.
+	e.HasLabel = e.HasAttribute
+	e.Label = e.Attribute
+	return e
 }
 
 func (m *Matcher) match(env env) (bool, error) {

internal/coreinternal/processor/filterexpr/matcher_test.go

@@ -142,11 +142,21 @@ func TestMatchGaugeDataPointByMetricAndHasLabel(t *testing.T) {
 	assert.True(t, testMatchGauge(t, "my.metric", expression, map[string]pdata.AttributeValue{"foo": pdata.NewAttributeValueString("")}))
 }
 
+func TestMatchGaugeDataPointByMetricAndHasAttribute(t *testing.T) {
+	expression := `MetricName == 'my.metric' && HasAttribute("foo")`
+	assert.True(t, testMatchGauge(t, "my.metric", expression, map[string]pdata.AttributeValue{"foo": pdata.NewAttributeValueString("")}))
+}
+
 func TestMatchGaugeDataPointByMetricAndLabelValue(t *testing.T) {
 	expression := `MetricName == 'my.metric' && Label("foo") == "bar"`
 	assert.False(t, testMatchGauge(t, "my.metric", expression, map[string]pdata.AttributeValue{"foo": pdata.NewAttributeValueString("")}))
 }
 
+func TestMatchGaugeDataPointByMetricAndAttributeValue(t *testing.T) {
+	expression := `MetricName == 'my.metric' && Attribute("foo") == "bar"`
+	assert.False(t, testMatchGauge(t, "my.metric", expression, map[string]pdata.AttributeValue{"foo": pdata.NewAttributeValueString("")}))
+}
+
 func TestNonMatchGaugeDataPointByMetricAndLabelValue(t *testing.T) {
 	expression := `MetricName == 'my.metric' && Label("foo") == "bar"`
 	assert.False(t, testMatchGauge(t, "my.metric", expression, map[string]pdata.AttributeValue{"foo": pdata.NewAttributeValueString("")}))

processor/filterprocessor/README.md

@@ -98,12 +98,16 @@ Made available to the expression environment are the following:
 
 * `MetricName`
     a variable containing the current Metric's name
+* `Attribute(name)`
+  a function that takes an attribute name string as an argument and returns a string: the value of an attribute with that
+  name if one exists, or ""
+* `HasAttribute(name)`
+  a function that takes an attribute name string as an argument and returns a boolean: true if the datapoint has an attribute
+  with that name, false otherwise
 * `Label(name)`
-    a function that takes a label name string as an argument and returns a string: the value of a label with that
-    name if one exists, or ""
+  Alias for `Attribute(name)`. Deprecated.
 * `HasLabel(name)`
-    a function that takes a label name string as an argument and returns a boolean: true if the datapoint has a label
-    with that name, false otherwise
+  Alias for `HasLabel(name)`. Deprecated.
 
 Example:
 
@@ -114,11 +118,11 @@ processors:
       exclude:
         match_type: expr
         expressions:
-        - MetricName == "my.metric" && Label("my_label") == "abc123"
+        - MetricName == "my.metric" && Attribute("my_attr") == "abc123"
 ```
 
 The above config will filter out any Metric that both has the name "my.metric" and has at least one datapoint
-with a label of 'my_label="abc123"'.
+with an attribute of 'my_attr="abc123"'.
 
 ### Support for multiple expressions