From 8e42b9e17386a364a3c2661bdcf51c1e193fa2ba Mon Sep 17 00:00:00 2001
From: Ross McDonald <ross@influxdb.com>
Date: Fri, 2 Sep 2016 16:50:23 -0500
Subject: [PATCH] Add a raw TCP handler to alert node.

---
 CHANGELOG.md      | 10 ++++++++++
 alert.go          | 32 ++++++++++++++++++++++++++++++++
 pipeline/alert.go | 25 +++++++++++++++++++++++++
 3 files changed, 67 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea51e6402..36ca22e10 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,15 @@
 # Changelog
 
+## v1.0.1 [unreleased]
+
+### Release Notes
+
+### Features
+
+- [#873](https://github.com/influxdata/kapacitor/pull/873): Add TCP alert handler
+
+### Bugfixes
+
 ## v1.0.0 [2016-09-02]
 
 ### Release Notes
diff --git a/alert.go b/alert.go
index 89d152f09..2a5689d15 100644
--- a/alert.go
+++ b/alert.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	html "html/template"
 	"log"
+	"net"
 	"net/http"
 	"os"
 	"os/exec"
@@ -173,6 +174,11 @@ func newAlertNode(et *ExecutingTask, n *pipeline.AlertNode, l *log.Logger) (an *
 		an.handlers = append(an.handlers, func(ad *AlertData) { an.handlePost(post, ad) })
 	}
 
+	for _, tcp := range n.TcpHandlers {
+		tcp := tcp
+		an.handlers = append(an.handlers, func(ad *AlertData) { an.handleTcp(tcp, ad) })
+	}
+
 	for _, email := range n.EmailHandlers {
 		email := email
 		an.handlers = append(an.handlers, func(ad *AlertData) { an.handleEmail(email, ad) })
@@ -910,6 +916,32 @@ func (a *AlertNode) handlePost(post *pipeline.PostHandler, ad *AlertData) {
 	return
 }
 
+func (a *AlertNode) handleTcp(tcp *pipeline.TcpHandler, ad *AlertData) {
+	buf := a.bufPool.Get().(*bytes.Buffer)
+	defer func() {
+		buf.Reset()
+		a.bufPool.Put(buf)
+	}()
+
+	err := json.NewEncoder(buf).Encode(ad)
+	if err != nil {
+		a.logger.Println("E! failed to marshal alert data json", err)
+		return
+	}
+
+	conn, err := net.Dial("tcp", tcp.Address)
+	if err != nil {
+		a.logger.Println("E! failed to connect", err)
+		return
+	}
+	defer conn.Close()
+
+	buf.WriteByte("\n")
+	conn.Write(buf.Bytes())
+
+	return
+}
+
 func (a *AlertNode) handleEmail(email *pipeline.EmailHandler, ad *AlertData) {
 	if a.et.tm.SMTPService != nil {
 		err := a.et.tm.SMTPService.SendMail(email.ToList, ad.Message, ad.Details)
diff --git a/pipeline/alert.go b/pipeline/alert.go
index bec421f69..7be526112 100644
--- a/pipeline/alert.go
+++ b/pipeline/alert.go
@@ -37,6 +37,7 @@ const defaultLogFileMode = 0600
 //
 //    * log -- log alert data to file.
 //    * post -- HTTP POST data to a specified URL.
+//    * tcp -- Send data to a specified address via raw TCP.
 //    * email -- Send and email with alert data.
 //    * exec -- Execute a command passing alert data over STDIN.
 //    * HipChat -- Post alert message to HipChat room.
@@ -79,6 +80,7 @@ const defaultLogFileMode = 0600
 //           .crit(lambda: "value" > 30)
 //           .post("http://example.com/api/alert")
 //           .post("http://another.example.com/api/alert")
+//           .tcp("exampleendpoint.com:5678")
 //           .email('oncall@example.com')
 //
 //
@@ -283,6 +285,10 @@ type AlertNode struct {
 	// tick:ignore
 	PostHandlers []*PostHandler `tick:"Post"`
 
+	// Send the JSON alert data to the specified endpoint via TCP.
+	// tick:ignore
+	TcpHandlers []*TcpHandler `tick:"Tcp"`
+
 	// Email handlers
 	// tick:ignore
 	EmailHandlers []*EmailHandler `tick:"Email"`
@@ -464,6 +470,25 @@ type PostHandler struct {
 	URL string
 }
 
+// Send JSON alert data to a specified address over TCP.
+// tick:property
+func (a *AlertNode) Tcp(address string) *TcpHandler {
+	tcp := &TcpHandler{
+		AlertNode: a,
+		Address:   address,
+	}
+	a.TcpHandlers = append(a.TcpHandlers, tcp)
+	return tcp
+}
+
+// tick:embedded:AlertNode.Tcp
+type TcpHandler struct {
+	*AlertNode
+
+	// The endpoint address.
+	Address string
+}
+
 // Email the alert data.
 //
 // If the To list is empty, the To addresses from the configuration are used.