add flags

Signed-off-by: Jess Frazelle <acidburn@microsoft.com>

k8scan/main.go

@@ -4,6 +4,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"errors"
+	"flag"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -17,18 +18,56 @@ import (
 	"time"
 
 	"github.com/Sirupsen/logrus"
+	mailgun "github.com/mailgun/mailgun-go"
 )
 
 const (
-	cidr = "0.0.0.0/0"
+	defaultCIDR = "0.0.0.0/0"
 
 	arinAPIEndpoint = "http://whois.arin.net/rest/ip/%s"
+
+	emailSender = "k8scan@jessfraz.com"
 )
 
 var (
+	timeoutPing time.Duration
+	timeoutGet  time.Duration
+
+	cidr string
+
 	ports = []int{80, 443, 9001, 8001}
+
+	mailgunDomain  string
+	mailgunAPIKey  string
+	emailRecipient string
+
+	debug bool
 )
 
+func init() {
+	flag.DurationVar(&timeoutPing, "timeout-ping", 2*time.Second, "Timeout for checking that the port is open")
+	flag.DurationVar(&timeoutGet, "timeout-get", 10*time.Second, "Timeout for getting the contents of the URL")
+
+	flag.StringVar(&cidr, "cidr", defaultCIDR, "IP CIDR to scan")
+
+	flag.StringVar(&mailgunAPIKey, "mailgun-api-key", "", "Mailgun API Key to use for sending email (optional)")
+	flag.StringVar(&mailgunDomain, "mailgun-domain", "", "Mailgun Domain to use for sending email (optional)")
+	flag.StringVar(&emailRecipient, "email-recipient", "", "Recipient for email notifications (optional)")
+
+	flag.BoolVar(&debug, "d", false, "Run in debug mode")
+
+	flag.Usage = func() {
+		flag.PrintDefaults()
+	}
+
+	flag.Parse()
+
+	// set log level
+	if debug {
+		logrus.SetLevel(logrus.DebugLevel)
+	}
+}
+
 func main() {
 	// On ^C, or SIGTERM handle exit.
 	c := make(chan os.Signal, 1)
@@ -47,6 +86,9 @@ func main() {
 	log.SetOutput(ioutil.Discard)
 
 	logrus.Infof("Scanning for Kubernetes Dashboards and API Servers on %s over port range %#v", cidr, ports)
+	if len(mailgunDomain) > 0 && len(mailgunAPIKey) > 0 && len(emailRecipient) > 0 {
+		logrus.Infof("Using Mailgun Domain %s, API Key %s to send emails to %s", mailgunDomain, mailgunAPIKey, emailRecipient)
+	}
 	logrus.Infof("This may take a bit...")
 
 	startTime := time.Now()
@@ -83,25 +125,31 @@ func scanIP(ip string, port int) {
 	}
 
 	// Check if it's a kubernetes dashboard.
-	ok = isKubernetesDashboard(ip, port)
+	ok, uri := isKubernetesDashboard(ip, port)
 	if !ok {
 		return
 	}
 
-	fmt.Printf("%s:%d\n", ip, port)
 	// Get the info for the ip address.
 	info, err := getIPInfo(ip)
 	if err != nil {
 		logrus.Warnf("ip info err: %v", err)
-		return
 	}
+
 	fmt.Printf("%s:%d\t%s\t%s\t%s\n",
 		ip, port,
 		info.Net.Organization.Handle, info.Net.Organization.Name, info.Net.Organization.Reference)
+
+	// send an email
+	if len(mailgunDomain) > 0 && len(mailgunAPIKey) > 0 && len(emailRecipient) > 0 {
+		if err := sendEmail(uri, ip, port, info); err != nil {
+			logrus.Warn(err)
+		}
+	}
 }
 
 func portOpen(ip string, port int) bool {
-	c, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%d", ip, port), 2*time.Second)
+	c, err := net.DialTimeout("tcp", fmt.Sprintf("%s:%d", ip, port), timeoutPing)
 	if err != nil {
 		// logrus.Warnf("listen at %s:%s failed: %v", ip, port, err)
 		return false
@@ -111,9 +159,9 @@ func portOpen(ip string, port int) bool {
 	return true
 }
 
-func isKubernetesDashboard(ip string, port int) bool {
+func isKubernetesDashboard(ip string, port int) (bool, string) {
 	client := &http.Client{
-		Timeout: time.Second * 10,
+		Timeout: timeoutGet,
 		Transport: &http.Transport{
 			TLSClientConfig: &tls.Config{
 				InsecureSkipVerify: true,
@@ -140,24 +188,23 @@ func isKubernetesDashboard(ip string, port int) bool {
 	}
 	if err != nil {
 		//logrus.Warnf("getting %s:%s failed: %v", ip, port, err)
-		return false
+		return false, ""
 	}
 	defer resp.Body.Close()
 
 	b, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return false
+		return false, ""
 	}
 
 	body := strings.ToLower(string(b))
 	if (strings.Contains(body, "kubernetes") && strings.Contains(body, "dashboard")) ||
 		(strings.Contains(body, `"versions"`) && strings.Contains(body, `"serverAddress`)) ||
 		(strings.Contains(body, `"paths"`) && strings.Contains(body, `"/api"`)) {
-		logrus.Infof("uri: %s", uri)
+		return true, uri
-		return true
 	}
 
-	return false
+	return false, ""
 }
 
 type ARINResponse struct {
@@ -202,3 +249,32 @@ func inc(ip net.IP) {
 		}
 	}
 }
+
+func sendEmail(uri, ip string, port int, arinInfo ARINResponse) error {
+	mailgunClient := mailgun.NewMailgun(mailgunDomain, mailgunAPIKey, "")
+
+	msg, _, err := mailgunClient.Send(mailgunClient.NewMessage(
+		/* From */ fmt.Sprintf("%s <%s>", emailSender, emailSender),
+		/* Subject */ fmt.Sprintf("[k8scan]: found dashboard %s", uri),
+		/* Body */ fmt.Sprintf(`Time: %s
+
+IP: %s:%d
+URL: %s
+
+ARIN: %s
+	  %s
+	  %s
+`,
+			time.Now().Format(time.UnixDate),
+			arinInfo.Net.Organization.Handle,
+			arinInfo.Net.Organization.Name,
+			arinInfo.Net.Organization.Reference,
+		),
+		/* To */ emailRecipient,
+	))
+	if err != nil {
+		return fmt.Errorf("sending Mailgun message failed: response: %#v error: %v", msg, err)
+	}
+
+	return nil
+}