Don't allow inputs to overwrite host tag

closes #1054

This affects tags in the following plugins:

- cassandra
- disque
- rethinkdb

CHANGELOG.md

@@ -24,6 +24,10 @@ for more details.
 only. Previously there was an undocumented behavior where filters would match
 based on _prefix_ in addition to globs. This means that a filter like
 `fielddrop = ["time_"]` will need to be changed to `fielddrop = ["time_*"]`
+- The following plugins have changed their tags to _not_ overwrite the host tag:
+  - cassandra: `host -> cassandra_host`
+  - disque: `host -> disque_host`
+  - rethinkdb: `host -> rethinkdb_host`
 
 ### Features
 
@@ -31,6 +35,7 @@ based on _prefix_ in addition to globs. This means that a filter like
 - [#1015](https://github.com/influxdata/telegraf/pull/1015): Docker plugin schema refactor.
 - [#889](https://github.com/influxdata/telegraf/pull/889): Improved MySQL plugin. Thanks @maksadbek!
 - [#1060](https://github.com/influxdata/telegraf/pull/1060): TTL metrics added to MongoDB input plugin
+- [#1056](https://github.com/influxdata/telegraf/pull/1056): Don't allow inputs to overwrite host tags.
 
 ### Bugfixes
 

agent/accumulator.go

@@ -84,17 +84,13 @@ func (ac *accumulator) AddFields(
 	if tags == nil {
 		tags = make(map[string]string)
 	}
-	// Apply plugin-wide tags if set
-	for k, v := range ac.inputConfig.Tags {
-		if _, ok := tags[k]; !ok {
-			tags[k] = v
-		}
-	}
 	// Apply daemon-wide tags if set
 	for k, v := range ac.defaultTags {
-		if _, ok := tags[k]; !ok {
 		tags[k] = v
 	}
+	// Apply plugin-wide tags if set
+	for k, v := range ac.inputConfig.Tags {
+		tags[k] = v
 	}
 	ac.inputConfig.Filter.FilterTags(tags)
 

plugins/inputs/cassandra/cassandra.go

@@ -9,17 +9,9 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/url"
-	//"reflect"
 	"strings"
 )
 
-/*type Server struct {
-	Host     string
-	Username string
-	Password string
-	Port     string
-}*/
-
 type JolokiaClient interface {
 	MakeRequest(req *http.Request) (*http.Response, error)
 }
@@ -55,12 +47,6 @@ type jmxMetric interface {
 	addTagsFields(out map[string]interface{})
 }
 
-func addServerTags(host string, tags map[string]string) {
-	if host != "" && host != "localhost" && host != "127.0.0.1" {
-		tags["host"] = host
-	}
-}
-
 func newJavaMetric(host string, metric string,
 	acc telegraf.Accumulator) *javaMetric {
 	return &javaMetric{host: host, metric: metric, acc: acc}
@@ -120,7 +106,7 @@ func (j javaMetric) addTagsFields(out map[string]interface{}) {
 
 	tokens := parseJmxMetricRequest(mbean)
 	addTokensToTags(tokens, tags)
-	addServerTags(j.host, tags)
+	tags["cassandra_host"] = j.host
 
 	if _, ok := tags["mname"]; !ok {
 		//Queries for a single value will not return a "name" tag in the response.
@@ -148,7 +134,7 @@ func addCassandraMetric(mbean string, c cassandraMetric,
 	fields := make(map[string]interface{})
 	tokens := parseJmxMetricRequest(mbean)
 	addTokensToTags(tokens, tags)
-	addServerTags(c.host, tags)
+	tags["cassandra_host"] = c.host
 	addValuesAsFields(values, fields, tags["mname"])
 	c.acc.AddFields(tokens["class"]+tokens["type"], fields, tags)
 

plugins/inputs/cassandra/cassandra_test.go

@@ -163,12 +163,12 @@ func TestHttpJsonJavaMultiValue(t *testing.T) {
 		"HeapMemoryUsage_used":      203288528.0,
 	}
 	tags1 := map[string]string{
-		"host":  "10.10.10.10",
+		"cassandra_host": "10.10.10.10",
 		"mname":          "HeapMemoryUsage",
 	}
 
 	tags2 := map[string]string{
-		"host":  "10.10.10.11",
+		"cassandra_host": "10.10.10.11",
 		"mname":          "HeapMemoryUsage",
 	}
 	acc.AssertContainsTaggedFields(t, "javaMemory", fields, tags1)
@@ -190,7 +190,7 @@ func TestHttpJsonJavaMultiType(t *testing.T) {
 	}
 
 	tags := map[string]string{
-		"host":  "10.10.10.10",
+		"cassandra_host": "10.10.10.10",
 		"mname":          "ConcurrentMarkSweep",
 	}
 	acc.AssertContainsTaggedFields(t, "javaGarbageCollector", fields, tags)
@@ -231,7 +231,7 @@ func TestHttpJsonCassandraMultiValue(t *testing.T) {
 	}
 
 	tags := map[string]string{
-		"host":     "10.10.10.10",
+		"cassandra_host": "10.10.10.10",
 		"mname":          "ReadLatency",
 		"keyspace":       "test_keyspace1",
 		"scope":          "test_table",
@@ -268,14 +268,14 @@ func TestHttpJsonCassandraNestedMultiValue(t *testing.T) {
 	}
 
 	tags1 := map[string]string{
-		"host":     "10.10.10.10",
+		"cassandra_host": "10.10.10.10",
 		"mname":          "ReadLatency",
 		"keyspace":       "test_keyspace1",
 		"scope":          "test_table1",
 	}
 
 	tags2 := map[string]string{
-		"host":     "10.10.10.10",
+		"cassandra_host": "10.10.10.10",
 		"mname":          "ReadLatency",
 		"keyspace":       "test_keyspace2",
 		"scope":          "test_table2",

plugins/inputs/disque/disque.go

@@ -162,7 +162,7 @@ func (g *Disque) gatherServer(addr *url.URL, acc telegraf.Accumulator) error {
 	var read int
 
 	fields := make(map[string]interface{})
-	tags := map[string]string{"host": addr.String()}
+	tags := map[string]string{"disque_host": addr.String()}
 	for read < sz {
 		line, err := r.ReadString('\n')
 		if err != nil {

plugins/inputs/rethinkdb/rethinkdb_server.go

@@ -97,8 +97,8 @@ func (s *Server) getServerStatus() error {
 
 func (s *Server) getDefaultTags() map[string]string {
 	tags := make(map[string]string)
-	tags["host"] = s.Url.Host
+	tags["rethinkdb_host"] = s.Url.Host
-	tags["hostname"] = s.serverStatus.Network.Hostname
+	tags["rethinkdb_hostname"] = s.serverStatus.Network.Hostname
 	return tags
 }
 

plugins/inputs/rethinkdb/rethinkdb_server_test.go

@@ -20,8 +20,8 @@ func TestGetDefaultTags(t *testing.T) {
 		in  string
 		out string
 	}{
-		{"host", server.Url.Host},
+		{"rethinkdb_host", server.Url.Host},
-		{"hostname", server.serverStatus.Network.Hostname},
+		{"rethinkdb_hostname", server.serverStatus.Network.Hostname},
 	}
 	defaultTags := server.getDefaultTags()
 	for _, tt := range tagTests {