Check for empty tag value before metric allocation

metric/metric.go

@@ -44,13 +44,18 @@ func New(
  // pre-allocate exact size of the tags slice
  taglen := 0
  for k, v := range tags {
- // TODO check that length of tag key & value are > 0
+ if len(k) == 0 || len(v) == 0 {
+ continue
+ }
  taglen += 2 + len(escape(k, "tagkey")) + len(escape(v, "tagval"))
  }
  m.tags = make([]byte, taglen)
 
  i := 0
  for k, v := range tags {
+ if len(k) == 0 || len(v) == 0 {
+ continue
+ }
  m.tags[i] = ','
  i++
  i += copy(m.tags[i:], escape(k, "tagkey"))

metric/metric_test.go

@@ -625,3 +625,26 @@ func TestNewMetricFailNaN(t *testing.T) {
  _, err := New("cpu", tags, fields, now)
  assert.NoError(t, err)
 }
+
+func TestEmptyTagValueOrKey(t *testing.T) {
+ now := time.Now()
+
+ tags := map[string]string{
+ "host": "localhost",
+ "emptytag": "",
+ "": "valuewithoutkey",
+ }
+ fields := map[string]interface{}{
+ "usage_idle": float64(99),
+ }
+ m, err := New("cpu", tags, fields, now)
+
+ assert.True(t, m.HasTag("host"))
+ assert.False(t, m.HasTag("emptytag"))
+ assert.Equal(t,
+ fmt.Sprintf("cpu,host=localhost usage_idle=99 %d\n", now.UnixNano()),
+ m.String())
+
+ assert.NoError(t, err)
+
+}

plugins/inputs/prometheus/parser_test.go

@@ -111,11 +111,9 @@ func TestParseValidPrometheus(t *testing.T) {
  "gauge": float64(1),
  }, metrics[0].Fields())
  assert.Equal(t, map[string]string{
- "osVersion": "CentOS Linux 7 (Core)",
- "dockerVersion": "1.8.2",
- "kernelVersion": "3.10.0-229.20.1.el7.x86_64",
- "cadvisorRevision": "",
- "cadvisorVersion": "",
+ "osVersion": "CentOS Linux 7 (Core)",
+ "dockerVersion": "1.8.2",
+ "kernelVersion": "3.10.0-229.20.1.el7.x86_64",
  }, metrics[0].Tags())
 
  // Counter value

plugins/parsers/nagios/parser_test.go

@@ -67,7 +67,7 @@ func TestParseValidOutput(t *testing.T) {
  assert.Equal(t, map[string]interface{}{
  "value": float64(0.008457),
  }, metrics[0].Fields())
- assert.Equal(t, map[string]string{"unit": ""}, metrics[0].Tags())
+ assert.Equal(t, map[string]string{}, metrics[0].Tags())
 }
 
 func TestParseInvalidOutput(t *testing.T) {