Support specifying influxdb retention policy

closes #692

plugins/outputs/influxdb/influxdb.go

@@ -18,15 +18,16 @@ import (
 
 type InfluxDB struct {
 	// URL is only for backwards compatability
-	URL        string
-	URLs       []string `toml:"urls"`
-	Username   string
-	Password   string
-	Database   string
-	UserAgent  string
-	Precision  string
-	Timeout    internal.Duration
-	UDPPayload int `toml:"udp_payload"`
+	URL             string
+	URLs            []string `toml:"urls"`
+	Username        string
+	Password        string
+	Database        string
+	UserAgent       string
+	Precision       string
+	RetentionPolicy string
+	Timeout         internal.Duration
+	UDPPayload      int `toml:"udp_payload"`
 
 	// Path to CA file
 	SSLCA string `toml:"ssl_ca"`
@@ -46,10 +47,12 @@ var sampleConfig = `
   ## this means that only ONE of the urls will be written to each interval.
   # urls = ["udp://localhost:8089"] # UDP endpoint example
   urls = ["http://localhost:8086"] # required
-  ## The target database for metrics (telegraf will create it if not exists)
+  ## The target database for metrics (telegraf will create it if not exists).
   database = "telegraf" # required
+  ## Retention policy to write to.
+  retention_policy = "default"
   ## Precision of writes, valid values are "ns", "us" (or "µs"), "ms", "s", "m", "h".
-  ## note: using "s" precision greatly improves InfluxDB compression
+  ## note: using "s" precision greatly improves InfluxDB compression.
   precision = "s"
 
   ## Write timeout (for the InfluxDB client), formatted as a string.
@@ -164,8 +167,9 @@ func (i *InfluxDB) Write(metrics []telegraf.Metric) error {
 		}
 	}
 	bp, err := client.NewBatchPoints(client.BatchPointsConfig{
-		Database:  i.Database,
-		Precision: i.Precision,
+		Database:        i.Database,
+		Precision:       i.Precision,
+		RetentionPolicy: i.RetentionPolicy,
 	})
 	if err != nil {
 		return err