Add tcp/udp check connection input plugin

closes #650

plugins/inputs/net_response/net_response.go

@@ -0,0 +1,196 @@
+package net_response
+
+import (
+	"bufio"
+	"errors"
+	"net"
+	"net/textproto"
+	"regexp"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+// NetResponses struct
+type NetResponse struct {
+	Address     string
+	Timeout     float64
+	ReadTimeout float64
+	Send        string
+	Expect      string
+	Protocol    string
+}
+
+func (_ *NetResponse) Description() string {
+	return "TCP or UDP 'ping' given url and collect response time in seconds"
+}
+
+var sampleConfig = `
+  ### Protocol, must be "tcp" or "udp"
+  protocol = "tcp"
+  ### Server address (default localhost)
+  address = "github.com:80"
+  ### Set timeout (default 1.0 seconds)
+  timeout = 1.0
+  ### Set read timeout (default 1.0 seconds)
+  read_timeout = 1.0
+  ### Optional string sent to the server
+  # send = "ssh"
+  ### Optional expected string in answer
+  # expect = "ssh"
+`
+
+func (_ *NetResponse) SampleConfig() string {
+	return sampleConfig
+}
+
+func (t *NetResponse) TcpGather() (map[string]interface{}, error) {
+	// Prepare fields
+	fields := make(map[string]interface{})
+	// Start Timer
+	start := time.Now()
+	// Resolving
+	tcpAddr, err := net.ResolveTCPAddr("tcp", t.Address)
+	// Connecting
+	conn, err := net.DialTCP("tcp", nil, tcpAddr)
+	// Stop timer
+	responseTime := time.Since(start).Seconds()
+	// Handle error
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+	// Send string if needed
+	if t.Send != "" {
+		msg := []byte(t.Send)
+		conn.Write(msg)
+		conn.CloseWrite()
+		// Stop timer
+		responseTime = time.Since(start).Seconds()
+	}
+	// Read string if needed
+	if t.Expect != "" {
+		// Set read timeout
+		conn.SetReadDeadline(time.Now().Add(time.Duration(t.ReadTimeout) * time.Second))
+		// Prepare reader
+		reader := bufio.NewReader(conn)
+		tp := textproto.NewReader(reader)
+		// Read
+		data, err := tp.ReadLine()
+		// Stop timer
+		responseTime = time.Since(start).Seconds()
+		// Handle error
+		if err != nil {
+			fields["string_found"] = false
+		} else {
+			// Looking for string in answer
+			RegEx := regexp.MustCompile(`.*` + t.Expect + `.*`)
+			find := RegEx.FindString(string(data))
+			if find != "" {
+				fields["string_found"] = true
+			} else {
+				fields["string_found"] = false
+			}
+		}
+
+	}
+	fields["response_time"] = responseTime
+	return fields, nil
+}
+
+func (u *NetResponse) UdpGather() (map[string]interface{}, error) {
+	// Prepare fields
+	fields := make(map[string]interface{})
+	// Start Timer
+	start := time.Now()
+	// Resolving
+	udpAddr, err := net.ResolveUDPAddr("udp", u.Address)
+	LocalAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:0")
+	// Connecting
+	conn, err := net.DialUDP("udp", LocalAddr, udpAddr)
+	defer conn.Close()
+	// Handle error
+	if err != nil {
+		return nil, err
+	}
+	// Send string
+	msg := []byte(u.Send)
+	conn.Write(msg)
+	// Read string
+	// Set read timeout
+	conn.SetReadDeadline(time.Now().Add(time.Duration(u.ReadTimeout) * time.Second))
+	// Read
+	buf := make([]byte, 1024)
+	_, _, err = conn.ReadFromUDP(buf)
+	// Stop timer
+	responseTime := time.Since(start).Seconds()
+	// Handle error
+	if err != nil {
+		return nil, err
+	} else {
+		// Looking for string in answer
+		RegEx := regexp.MustCompile(`.*` + u.Expect + `.*`)
+		find := RegEx.FindString(string(buf))
+		if find != "" {
+			fields["string_found"] = true
+		} else {
+			fields["string_found"] = false
+		}
+	}
+	fields["response_time"] = responseTime
+	return fields, nil
+}
+
+func (c *NetResponse) Gather(acc telegraf.Accumulator) error {
+	// Set default values
+	if c.Timeout == 0 {
+		c.Timeout = 1.0
+	}
+	if c.ReadTimeout == 0 {
+		c.ReadTimeout = 1.0
+	}
+	// Check send and expected string
+	if c.Protocol == "udp" && c.Send == "" {
+		return errors.New("Send string cannot be empty")
+	}
+	if c.Protocol == "udp" && c.Expect == "" {
+		return errors.New("Expected string cannot be empty")
+	}
+	// Prepare host and port
+	host, port, err := net.SplitHostPort(c.Address)
+	if err != nil {
+		return err
+	}
+	if host == "" {
+		c.Address = "localhost:" + port
+	}
+	if port == "" {
+		return errors.New("Bad port")
+	}
+	// Prepare data
+	tags := map[string]string{"host": host, "port": port}
+	var fields map[string]interface{}
+	// Gather data
+	if c.Protocol == "tcp" {
+		fields, err = c.TcpGather()
+		tags["protocol"] = "tcp"
+	} else if c.Protocol == "udp" {
+		fields, err = c.UdpGather()
+		tags["protocol"] = "udp"
+	} else {
+		return errors.New("Bad protocol")
+	}
+	if err != nil {
+		return err
+	}
+	// Add metrics
+	acc.AddFields("net_response", fields, tags)
+	return nil
+}
+
+func init() {
+	inputs.Add("net_response", func() telegraf.Input {
+		return &NetResponse{}
+	})
+}