Add network option to dns_query (influxdata#3042)

plugins/inputs/dns_query/README.md

@@ -8,19 +8,23 @@ The DNS plugin gathers dns query times in miliseconds - like [Dig](https://en.wi
 # Sample Config:
 [[inputs.dns_query]]
   ## servers to query
-  servers = ["8.8.8.8"] # required
+  servers = ["8.8.8.8"]
 
-  ## Domains or subdomains to query. "." (root) is default
-  domains = ["."] # optional
+  ## Network is the network protocol name.
+  # network = "udp"
 
-  ## Query record type. Posible values: A, AAAA, ANY, CNAME, MX,  NS, PTR, SOA, SPF, SRV, TXT. Default is "NS"
-  record_type = "A" # optional
+  ## Domains or subdomains to query.
+  # domains = ["."]
 
-  ## Dns server port. 53 is default
-  port = 53 # optional
+  ## Query record type.
+  ## Posible values: A, AAAA, CNAME, MX, NS, PTR, TXT, SOA, SPF, SRV.
+  # record_type = "A"
 
-  ## Query timeout in seconds. Default is 2 seconds
-  timeout = 2 # optional
+  ## Dns server port.
+  # port = 53
+
+  ## Query timeout in seconds.
+  # timeout = 2
 ```
 
 For querying more than one record type make:
@@ -46,6 +50,6 @@ For querying more than one record type make:
 ### Example output:
 
 ```
-./telegraf --config telegraf.conf --input-filter dns_query --test
+telegraf --input-filter dns_query --test
 > dns_query,domain=mjasion.pl,record_type=A,server=8.8.8.8 query_time_ms=67.189842 1456082743585760680
 ```

plugins/inputs/dns_query/dns_query.go

@@ -3,11 +3,12 @@ package dns_query
 import (
 	"errors"
 	"fmt"
-	"github.com/miekg/dns"
 	"net"
 	"strconv"
 	"time"
 
+	"github.com/miekg/dns"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
@@ -16,6 +17,9 @@ type DnsQuery struct {
 	// Domains or subdomains to query
 	Domains []string
 
+	// Network protocl name
+	Network string
+
 	// Server to query
 	Servers []string
 
@@ -31,20 +35,23 @@ type DnsQuery struct {
 
 var sampleConfig = `
   ## servers to query
-  servers = ["8.8.8.8"] # required
+  servers = ["8.8.8.8"]
 
-  ## Domains or subdomains to query. "."(root) is default
-  domains = ["."] # optional
+  ## Network is the network protocol name.
+  # network = "udp"
 
-  ## Query record type. Default is "A"
+  ## Domains or subdomains to query.
+  # domains = ["."]
+
+  ## Query record type.
   ## Posible values: A, AAAA, CNAME, MX, NS, PTR, TXT, SOA, SPF, SRV.
-  record_type = "A" # optional
+  # record_type = "A"
 
-  ## Dns server port. 53 is default
-  port = 53 # optional
+  ## Dns server port.
+  # port = 53
 
-  ## Query timeout in seconds. Default is 2 seconds
-  timeout = 2 # optional
+  ## Query timeout in seconds.
+  # timeout = 2
 `
 
 func (d *DnsQuery) SampleConfig() string {
@@ -76,6 +83,10 @@ func (d *DnsQuery) Gather(acc telegraf.Accumulator) error {
 }
 
 func (d *DnsQuery) setDefaultValues() {
+	if d.Network == "" {
+		d.Network = "udp"
+	}
+
 	if len(d.RecordType) == 0 {
 		d.RecordType = "NS"
 	}
@@ -99,6 +110,7 @@ func (d *DnsQuery) getDnsQueryTime(domain string, server string) (float64, error
 
 	c := new(dns.Client)
 	c.ReadTimeout = time.Duration(d.Timeout) * time.Second
+	c.Net = d.Network
 
 	m := new(dns.Msg)
 	recordType, err := d.parseRecordType()