Handle generated errors and make error messages conform to standards,…

… remove unnecessary else statements in broker

broker/broker.go

@@ -183,7 +183,9 @@ func proxyPolls(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	log.Println("Passing client offer to snowflake.")
-	w.Write(offer)
+	if _, err := w.Write(offer); err != nil {
+		log.Printf("proxyPolls unable to write offer with error: %v", err)
+	}
 }
 
 /*
@@ -217,14 +219,18 @@ func clientOffers(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 	case answer := <-snowflake.answerChannel:
 		log.Println("Client: Retrieving answer")
 		ctx.metrics.clientProxyMatchCount++
-		w.Write(answer)
+		if _, err := w.Write(answer); err != nil {
+			log.Printf("unable to write answer with error: %v", err)
+		}
 		// Initial tracking of elapsed time.
 		ctx.metrics.clientRoundtripEstimate = time.Since(startTime) /
 			time.Millisecond
 	case <-time.After(time.Second * ClientTimeout):
 		log.Println("Client: Timed out.")
 		w.WriteHeader(http.StatusGatewayTimeout)
-		w.Write([]byte("timed out waiting for answer!"))
+		if _, err := w.Write([]byte("timed out waiting for answer!")); err != nil {
+			log.Printf("unable to write timeout error, failed with error: %v", err)
+		}
 	}
 }
 
@@ -266,12 +272,16 @@ func debugHandler(ctx *BrokerContext, w http.ResponseWriter, r *http.Request) {
 	}
 	s += fmt.Sprintf("\tstandalone proxies: %d", standalones)
 	s += fmt.Sprintf("\n\tbrowser proxies: %d", browsers)
-	w.Write([]byte(s))
+	if _, err := w.Write([]byte(s)); err != nil {
+		log.Printf("writing proxy information returned error: %v ", err)
+	}
 }
 
 func robotsTxtHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
-	w.Write([]byte("User-agent: *\nDisallow: /\n"))
+	if _, err := w.Write([]byte("User-agent: *\nDisallow: /\n")); err != nil {
+		log.Printf("robotsTxtHandler unable to write, with this error: %v", err)
+	}
 }
 
 func metricsHandler(metricsFilename string, w http.ResponseWriter, r *http.Request) {
@@ -288,7 +298,9 @@ func metricsHandler(metricsFilename string, w http.ResponseWriter, r *http.Reque
 		return
 	}
 
-	io.Copy(w, metricsFile)
+	if _, err := io.Copy(w, metricsFile); err != nil {
+		log.Printf("copying metricsFile returned error: %v", err)
+	}
 }
 
 func main() {
@@ -317,7 +329,7 @@ func main() {
 	flag.Parse()
 
 	var err error
-	var metricsFile io.Writer = os.Stdout
+	var metricsFile io.Writer
 	var logOutput io.Writer = os.Stderr
 	//We want to send the log output through our scrubber first
 	log.SetOutput(&safelog.LogScrubber{Output: logOutput})
@@ -339,7 +351,7 @@ func main() {
 	ctx := NewBrokerContext(metricsLogger)
 
 	if !disableGeoip {
-		err := ctx.metrics.LoadGeoipDatabases(geoipDatabase, geoip6Database)
+		err = ctx.metrics.LoadGeoipDatabases(geoipDatabase, geoip6Database)
 		if err != nil {
 			log.Fatal(err.Error())
 		}
@@ -369,7 +381,9 @@ func main() {
 		for {
 			signal := <-sigChan
 			log.Println("Received signal:", signal, ". Reloading geoip databases.")
-			ctx.metrics.LoadGeoipDatabases(geoipDatabase, geoip6Database)
+			if err = ctx.metrics.LoadGeoipDatabases(geoipDatabase, geoip6Database); err != nil {
+				log.Printf("loading Geo IP databases returned error; %v", err)
+			}
 		}
 	}()
 

broker/geoip.go

@@ -93,7 +93,7 @@ func (table *GeoIPv6Table) Unlock() { (*table).lock.Unlock() }
 func geoipStringToIP(ipStr string) (net.IP, error) {
 	ip, err := strconv.ParseUint(ipStr, 10, 32)
 	if err != nil {
-		return net.IPv4(0, 0, 0, 0), fmt.Errorf("Error parsing IP %s", ipStr)
+		return net.IPv4(0, 0, 0, 0), fmt.Errorf("error parsing IP %s", ipStr)
 	}
 	var bytes [4]byte
 	bytes[0] = byte(ip & 0xFF)
@@ -115,7 +115,7 @@ func (table *GeoIPv4Table) parseEntry(candidate string) (*GeoIPEntry, error) {
 	parsedCandidate := strings.Split(candidate, ",")
 
 	if len(parsedCandidate) != 3 {
-		return nil, fmt.Errorf("Provided geoip file is incorrectly formatted. Could not parse line:\n%s", parsedCandidate)
+		return nil, fmt.Errorf("provided geoip file is incorrectly formatted. Could not parse line:\n%s", parsedCandidate)
 	}
 
 	low, err := geoipStringToIP(parsedCandidate[0])
@@ -190,7 +190,7 @@ func GeoIPLoadFile(table GeoIPTable, pathname string) error {
 	for scanner.Scan() {
 		entry, err := table.parseEntry(scanner.Text())
 		if err != nil {
-			return fmt.Errorf("Provided geoip file is incorrectly formatted. Line is: %+q", scanner.Text())
+			return fmt.Errorf("provided geoip file is incorrectly formatted. Line is: %+q", scanner.Text())
 		}
 
 		if entry != nil {

broker/metrics.go

@@ -121,7 +121,6 @@ func (m *Metrics) UpdateCountryStats(addr string) {
 	m.countryStats.counts[country]++
 	m.countryStats.addrs[addr] = true
 
-	return
 }
 
 func (m *Metrics) LoadGeoipDatabases(geoipDB string, geoip6DB string) error {
@@ -133,19 +132,16 @@ func (m *Metrics) LoadGeoipDatabases(geoipDB string, geoip6DB string) error {
 	if err != nil {
 		m.tablev4 = nil
 		return err
-	} else {
-		m.tablev4 = tablev4
 	}
+	m.tablev4 = tablev4
 
 	tablev6 := new(GeoIPv6Table)
 	err = GeoIPLoadFile(tablev6, geoip6DB)
 	if err != nil {
 		m.tablev6 = nil
 		return err
-	} else {
-		m.tablev6 = tablev6
 	}
-
+	m.tablev6 = tablev6
 	return nil
 }
 

broker/snowflake-broker_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"container/heap"
-	. "github.com/smartystreets/goconvey/convey"
 	"io/ioutil"
 	"log"
 	"net"
@@ -12,6 +11,8 @@ import (
 	"os"
 	"testing"
 	"time"
+
+	. "github.com/smartystreets/goconvey/convey"
 )
 
 func NullLogger() *log.Logger {
@@ -181,7 +182,7 @@ func TestBroker(t *testing.T) {
 			})
 
 			Convey("with error if the proxy writes too much data", func() {
-				data := bytes.NewReader(make([]byte, 100001, 100001))
+				data := bytes.NewReader(make([]byte, 100001))
 				r, err := http.NewRequest("POST", "snowflake.broker/answer", data)
 				r.Header.Set("X-Session-ID", "test")
 				So(err, ShouldBeNil)
@@ -385,7 +386,9 @@ func TestGeoip(t *testing.T) {
 
 		// Make sure things behave properly if geoip file fails to load
 		ctx := NewBrokerContext(NullLogger())
-		ctx.metrics.LoadGeoipDatabases("invalid_filename", "invalid_filename6")
+		if err := ctx.metrics.LoadGeoipDatabases("invalid_filename", "invalid_filename6"); err != nil {
+			log.Printf("loading geo ip databases returned error: %v", err)
+		}
 		ctx.metrics.UpdateCountryStats("127.0.0.1")
 		So(ctx.metrics.tablev4, ShouldEqual, nil)
 
@@ -504,6 +507,9 @@ func TestMetrics(t *testing.T) {
 
 			data = bytes.NewReader([]byte("test"))
 			r, err = http.NewRequest("POST", "snowflake.broker/proxy", data)
+			if err != nil {
+				log.Printf("unable to get NewRequest with error: %v", err)
+			}
 			r.Header.Set("X-Session-ID", "test")
 			r.RemoteAddr = "129.97.208.23:8888" //CA geoip
 			go func(ctx *BrokerContext) {