Fixup adding 'measurement' to logparser grok

closes #1434

CHANGELOG.md

@@ -43,6 +43,7 @@ should now look like:
 - [#1387](https://github.com/influxdata/telegraf/pull/1387): **Breaking Change** - Redis `role` tag renamed to `replication_role` to avoid global_tags override
 - [#1437](https://github.com/influxdata/telegraf/pull/1437): Fetching Galera status metrics in MySQL
 - [#1500](https://github.com/influxdata/telegraf/pull/1500): Aerospike plugin refactored to use official client lib.
+- [#1434](https://github.com/influxdata/telegraf/pull/1434): Add measurement name arg to logparser plugin.
 
 ### Bugfixes
 

plugins/inputs/logparser/grok/grok.go

@@ -56,7 +56,7 @@ type Parser struct {
 	Patterns           []string
 	CustomPatterns     string
 	CustomPatternFiles []string
-	Measurement string
+	Measurement        string
 
 	// typeMap is a map of patterns -> capture name -> modifier,
 	//   ie, {

plugins/inputs/logparser/grok/grok_test.go

@@ -83,6 +83,32 @@ func Benchmark_ParseLine_CustomPattern(b *testing.B) {
 	benchM = m
 }
 
+func TestMeasurementName(t *testing.T) {
+	p := &Parser{
+		Measurement: "my_web_log",
+		Patterns:    []string{"%{COMMON_LOG_FORMAT}"},
+	}
+	assert.NoError(t, p.Compile())
+
+	// Parse an influxdb POST request
+	m, err := p.ParseLine(`127.0.0.1 user-identifier frank [10/Oct/2000:13:55:36 -0700] "GET /apache_pb.gif HTTP/1.0" 200 2326`)
+	require.NotNil(t, m)
+	assert.NoError(t, err)
+	assert.Equal(t,
+		map[string]interface{}{
+			"resp_bytes":   int64(2326),
+			"auth":         "frank",
+			"client_ip":    "127.0.0.1",
+			"resp_code":    int64(200),
+			"http_version": float64(1.0),
+			"ident":        "user-identifier",
+			"request":      "/apache_pb.gif",
+		},
+		m.Fields())
+	assert.Equal(t, map[string]string{"verb": "GET"}, m.Tags())
+	assert.Equal(t, "my_web_log", m.Name())
+}
+
 func TestBuiltinInfluxdbHttpd(t *testing.T) {
 	p := &Parser{
 		Patterns: []string{"%{INFLUXDB_HTTPD_LOG}"},

plugins/inputs/logparser/logparser.go

@@ -58,6 +58,8 @@ const sampleConfig = `
     ##   %{COMMON_LOG_FORMAT}   (plain apache & nginx access logs)
     ##   %{COMBINED_LOG_FORMAT} (access logs + referrer & agent)
     patterns = ["%{INFLUXDB_HTTPD_LOG}"]
+    ## Name of the outputted measurement name.
+    measurement = "influxdb_log"
     ## Full path(s) to custom pattern files.
     custom_pattern_files = []
     ## Custom patterns can also be defined here. Put one pattern per line.