Enhance code quality analysis (#104)

* chore: add new Make targets.

* refactor: code review.

* chore(travis): go import path.

.travis.yml

@@ -7,15 +7,18 @@ go:
 
 sudo: false
 
+go_import_path: github.com/vulcand/oxy
+
+notifications:
+  email:
+    on_success: never
+    on_failure: change
+
 before_install:
+  - go get -u github.com/golang/lint/golint
+  - go get -u honnef.co/go/tools/cmd/{gosimple,staticcheck}
+  - go get -u github.com/client9/misspell/cmd/misspell
   - curl -sI https://github.com/golang/dep/releases/latest | grep -Fi Location  | tr -d '\r' | sed "s/tag/download/g" | awk -F " " '{ print $2 "/dep-linux-amd64"}' | wget --output-document=$GOPATH/bin/dep -i -
   - chmod +x $GOPATH/bin/dep
 
 install: make dependencies
-
-script:
-  - PKGS=$(go list ./... | grep -v '/vendor/')
-  - GOFILES=$(go list -f '{{range $index, $element := .GoFiles}}{{$.Dir}}/{{$element}}{{"\n"}}{{end}}' ./... | grep -v '/vendor/')
-  - go test -cover -race $PKGS
-  - go vet $PKGS
-  - diff -u <(echo -n) <(gofmt -d $GOFILES)

Makefile

@@ -1,8 +1,14 @@
 .PHONY: all
 
 PKGS := $(shell go list ./... | grep -v '/vendor/')
+TXT_FILES := $(shell find * -type f -not -path 'vendor/**')
+
+default: clean misspell vet test
 
 test: clean
+	go test -race -cover $(PKGS)
+
+test-verbose: clean
 	go test -v -race -cover $(PKGS)
 
 dependencies:
@@ -10,6 +16,27 @@ dependencies:
 
 clean:
 	find . -name flymake_* -delete
+	rm -f cover.out
+
+lint:
+	echo "golint:"
+	golint -set_exit_status $(PKGS)
+
+vet:
+	go vet $(PKGS)
+
+checks: vet lint check-fmt
+	echo "staticcheck:"
+	staticcheck $(PKGS)
+	echo "gosimple:"
+	gosimple $(PKGS)
+
+check-fmt: SHELL := /bin/bash
+check-fmt:
+	diff -u <(echo -n) <(gofmt -d $(GOFILES))
+
+misspell:
+	misspell -source=text -error $(TXT_FILES)
 
 test-package: clean
 	go test -v ./$(p)

buffer/buffer.go

@@ -1,5 +1,5 @@
 /*
-package buffer provides http.Handler middleware that solves several problems when dealing with http requests:
+Package buffer provides http.Handler middleware that solves several problems when dealing with http requests:
 
 Reads the entire request and response into buffer, optionally buffering it to disk for large requests.
 Checks the limits for the requests and responses, rejecting in case if the limit was exceeded.
@@ -51,18 +51,18 @@ import (
 )
 
 const (
-	// Store up to 1MB in RAM
+	// DefaultMemBodyBytes Store up to 1MB in RAM
 	DefaultMemBodyBytes = 1048576
-	// No limit by default
+	// DefaultMaxBodyBytes No limit by default
 	DefaultMaxBodyBytes = -1
-	// Maximum retry attempts
+	// DefaultMaxRetryAttempts Maximum retry attempts
 	DefaultMaxRetryAttempts = 10
 )
 
 var errHandler utils.ErrorHandler = &SizeErrHandler{}
 
 // Buffer is responsible for buffering requests and responses
-// It buffers large reqeuests and responses to disk,
+// It buffers large requests and responses to disk,
 type Buffer struct {
 	maxRequestBodyBytes int64
 	memRequestBodyBytes int64
@@ -212,7 +212,10 @@ func (s *Buffer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	// and we don'w want to mess with standard library
 	defer func() {
 		if body != nil {
-			body.Close()
+			errClose := body.Close()
+			if errClose != nil {
+				log.Errorf("vulcand/oxy/buffer: failed to close body, err: %v", errClose)
+			}
 		}
 	}()
 
@@ -303,7 +306,7 @@ func (s *Buffer) copyRequest(req *http.Request, body io.ReadCloser, bodySize int
 	if body == nil {
 		o.Body = nil
 	} else {
-		o.Body = ioutil.NopCloser(body)
+		o.Body = ioutil.NopCloser(body.(io.Reader))
 	}
 	return &o
 }

buffer/buffer_test.go

@@ -85,6 +85,7 @@ func (s *BFSuite) TestChunkedEncodingSuccess(c *C) {
 	c.Assert(err, IsNil)
 	fmt.Fprintf(conn, "POST / HTTP/1.1\r\nHost: 127.0.0.1:8080\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ntest\r\n5\r\ntest1\r\n5\r\ntest2\r\n0\r\n\r\n")
 	status, err := bufio.NewReader(conn).ReadString('\n')
+	c.Assert(err, IsNil)
 
 	c.Assert(reqBody, Equals, "testtest1test2")
 	c.Assert(status, Equals, "HTTP/1.1 200 OK\r\n")
@@ -116,8 +117,9 @@ func (s *BFSuite) TestChunkedEncodingLimitReached(c *C) {
 
 	conn, err := net.Dial("tcp", testutils.ParseURI(proxy.URL).Host)
 	c.Assert(err, IsNil)
-	fmt.Fprintf(conn, "POST / HTTP/1.1\r\nHost: 127.0.0.1:8080\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ntest\r\n5\r\ntest1\r\n5\r\ntest2\r\n0\r\n\r\n")
+	fmt.Fprint(conn, "POST / HTTP/1.1\r\nHost: 127.0.0.1:8080\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ntest\r\n5\r\ntest1\r\n5\r\ntest2\r\n0\r\n\r\n")
 	status, err := bufio.NewReader(conn).ReadString('\n')
+	c.Assert(err, IsNil)
 
 	c.Assert(status, Equals, "HTTP/1.1 413 Request Entity Too Large\r\n")
 }

cbreaker/cbreaker.go

@@ -1,4 +1,4 @@
-// package cbreaker implements circuit breaker similar to  https://github.com/Netflix/Hystrix/wiki/How-it-Works
+// Package cbreaker implements circuit breaker similar to  https://github.com/Netflix/Hystrix/wiki/How-it-Works
 //
 // Vulcan circuit breaker watches the error condtion to match
 // after which it activates the fallback scenario, e.g. returns the response code

cbreaker/cbreaker_test.go

@@ -90,7 +90,7 @@ func (s *CBSuite) TestFullCycle(c *C) {
 
 	cb.metrics = statsNetErrors(0.6)
 	s.advanceTime(defaultCheckPeriod + time.Millisecond)
-	re, _, err = testutils.Get(srv.URL)
+	_, _, err = testutils.Get(srv.URL)
 	c.Assert(err, IsNil)
 	c.Assert(cb.state, Equals, cbState(stateTripped))
 
@@ -139,7 +139,7 @@ func (s *CBSuite) TestRedirectWithPath(c *C) {
 	defer srv.Close()
 
 	cb.metrics = statsNetErrors(0.6)
-	re, _, err := testutils.Get(srv.URL)
+	_, _, err = testutils.Get(srv.URL)
 	c.Assert(err, IsNil)
 
 	client := &http.Client{
@@ -148,7 +148,7 @@ func (s *CBSuite) TestRedirectWithPath(c *C) {
 		},
 	}
 
-	re, err = client.Get(srv.URL + "/somePath")
+	re, err := client.Get(srv.URL + "/somePath")
 	c.Assert(err, NotNil)
 	c.Assert(re.StatusCode, Equals, http.StatusFound)
 	c.Assert(re.Header.Get("Location"), Equals, "http://localhost:6000/somePath")
@@ -166,7 +166,7 @@ func (s *CBSuite) TestRedirect(c *C) {
 	defer srv.Close()
 
 	cb.metrics = statsNetErrors(0.6)
-	re, _, err := testutils.Get(srv.URL)
+	_, _, err = testutils.Get(srv.URL)
 	c.Assert(err, IsNil)
 
 	client := &http.Client{
@@ -175,7 +175,7 @@ func (s *CBSuite) TestRedirect(c *C) {
 		},
 	}
 
-	re, err = client.Get(srv.URL + "/somePath")
+	re, err := client.Get(srv.URL + "/somePath")
 	c.Assert(err, NotNil)
 	c.Assert(re.StatusCode, Equals, http.StatusFound)
 	c.Assert(re.Header.Get("Location"), Equals, "http://localhost:5000")
@@ -193,13 +193,13 @@ func (s *CBSuite) TestTriggerDuringRecovery(c *C) {
 	defer srv.Close()
 
 	cb.metrics = statsNetErrors(0.6)
-	re, _, err := testutils.Get(srv.URL)
+	_, _, err = testutils.Get(srv.URL)
 	c.Assert(err, IsNil)
 	c.Assert(cb.state, Equals, cbState(stateTripped))
 
 	// We should be in recovering state by now
 	s.advanceTime(10*time.Second + time.Millisecond)
-	re, _, err = testutils.Get(srv.URL)
+	re, _, err := testutils.Get(srv.URL)
 	c.Assert(err, IsNil)
 	c.Assert(re.StatusCode, Equals, http.StatusServiceUnavailable)
 	c.Assert(cb.state, Equals, cbState(stateRecovering))

cbreaker/fallback.go

@@ -39,7 +39,10 @@ func (f *ResponseFallback) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	}
 	w.Header().Set("Content-Length", strconv.Itoa(len(f.r.Body)))
 	w.WriteHeader(f.r.StatusCode)
-	w.Write(f.r.Body)
+	_, err := w.Write(f.r.Body)
+	if err != nil {
+		log.Errorf("vulcand/oxy/fallback/response: failed to write response, err: %v", err)
+	}
 }
 
 type Redirect struct {
@@ -74,5 +77,8 @@ func (f *RedirectFallback) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 
 	w.Header().Set("Location", location)
 	w.WriteHeader(http.StatusFound)
-	w.Write([]byte(http.StatusText(http.StatusFound)))
+	_, err := w.Write([]byte(http.StatusText(http.StatusFound)))
+	if err != nil {
+		log.Errorf("vulcand/oxy/fallback/redirect: failed to write response, err: %v", err)
+	}
 }

connlimit/connlimit.go

@@ -78,7 +78,7 @@ func (cl *ConnLimiter) acquire(token string, amount int64) error {
 	}
 
 	cl.connections[token] += amount
-	cl.totalConnections += int64(amount)
+	cl.totalConnections += amount
 	return nil
 }
 
@@ -87,7 +87,7 @@ func (cl *ConnLimiter) release(token string, amount int64) {
 	defer cl.mutex.Unlock()
 
 	cl.connections[token] -= amount
-	cl.totalConnections -= int64(amount)
+	cl.totalConnections -= amount
 
 	// Otherwise it would grow forever
 	if cl.connections[token] == 0 {

connlimit/connlimit_test.go

@@ -38,8 +38,8 @@ func (s *ConnLimiterSuite) TestHitLimitAndRelease(c *C) {
 	defer srv.Close()
 
 	go func() {
-		re, _, err := testutils.Get(srv.URL, testutils.Header("Limit", "a"), testutils.Header("wait", "yes"))
-		c.Assert(err, IsNil)
+		re, _, errGet := testutils.Get(srv.URL, testutils.Header("Limit", "a"), testutils.Header("wait", "yes"))
+		c.Assert(errGet, IsNil)
 		c.Assert(re.StatusCode, Equals, http.StatusOK)
 	}()
 

forward/fwd.go

@@ -4,18 +4,17 @@
 package forward
 
 import (
+	"crypto/tls"
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"net/http/httputil"
 	"net/url"
 	"os"
+	"reflect"
 	"strings"
 	"time"
 
-	"crypto/tls"
-	"net/http/httputil"
-	"reflect"
-
 	"github.com/gorilla/websocket"
 	log "github.com/sirupsen/logrus"
 	"github.com/vulcand/oxy/utils"
@@ -280,18 +279,18 @@ func (f *httpForwarder) serveWebSocket(w http.ResponseWriter, req *http.Request,
 				return
 			}
 
-			conn, _, err := hijacker.Hijack()
-			if err != nil {
+			conn, _, errHij := hijacker.Hijack()
+			if errHij != nil {
 				log.Errorf("vulcand/oxy/forward/websocket: Failed to hijack responseWriter")
-				ctx.errHandler.ServeHTTP(w, req, err)
+				ctx.errHandler.ServeHTTP(w, req, errHij)
 				return
 			}
 			defer conn.Close()
 
-			err = resp.Write(conn)
-			if err != nil {
+			errWrite := resp.Write(conn)
+			if errWrite != nil {
 				log.Errorf("vulcand/oxy/forward/websocket: Failed to forward response")
-				ctx.errHandler.ServeHTTP(w, req, err)
+				ctx.errHandler.ServeHTTP(w, req, errWrite)
 				return
 			}
 		}
@@ -314,13 +313,13 @@ func (f *httpForwarder) serveWebSocket(w http.ResponseWriter, req *http.Request,
 
 	errc := make(chan error, 2)
 	replicate := func(dst io.Writer, src io.Reader, dstName string, srcName string) {
-		_, err := io.Copy(dst, src)
-		if err != nil {
-			f.log.Errorf("vulcand/oxy/forward/websocket: Error when copying from %s to %s using io.Copy: %v", srcName, dstName, err)
+		_, errCopy := io.Copy(dst, src)
+		if errCopy != nil {
+			f.log.Errorf("vulcand/oxy/forward/websocket: Error when copying from %s to %s using io.Copy: %v", srcName, dstName, errCopy)
 		} else {
 			f.log.Infof("vulcand/oxy/forward/websocket: Copying from %s to %s using io.Copy completed without error.", srcName, dstName)
 		}
-		errc <- err
+		errc <- errCopy
 	}
 
 	go replicate(targetConn.UnderlyingConn(), underlyingConn.UnderlyingConn(), "backend", "client")

forward/fwd_test.go

@@ -243,6 +243,7 @@ func (s *FwdSuite) TestEscapedURL(c *C) {
 	path := "/log/http%3A%2F%2Fwww.site.com%2Fsomething?a=b"
 
 	request, err := http.NewRequest("GET", proxy.URL, nil)
+	c.Assert(err, IsNil)
 	parsed := testutils.ParseURI(proxy.URL)
 	parsed.Opaque = path
 	request.URL = parsed

forward/fwd_websocket_test.go

@@ -290,16 +290,17 @@ func (s *FwdSuite) TestWebSocketUpgradeFailed(c *C) {
 	// First request works with 400
 	br := bufio.NewReader(conn)
 	resp, err := http.ReadResponse(br, req)
-
+	c.Assert(err, IsNil)
 	c.Assert(resp.StatusCode, Equals, 400)
 
 	req, err = http.NewRequest(http.MethodGet, "ws://127.0.0.1/ws2", nil)
+	c.Assert(err, IsNil)
 	req.Header.Add("upgrade", "websocket")
 	req.Header.Add("Connection", "upgrade")
 	req.Write(conn)
 
 	br = bufio.NewReader(conn)
-	resp, err = http.ReadResponse(br, req)
+	_, err = http.ReadResponse(br, req)
 	c.Assert(err, Equals, io.ErrUnexpectedEOF)
 }
 

forward/rewrite.go

@@ -14,7 +14,7 @@ type HeaderRewriter struct {
 	Hostname           string
 }
 
-// clean up IP in case if it is ipv6 address and it has {zone} infromation in it, like "[fe80::d806:a55d:eb1b:49cc%vEthernet (vmxnet3 Ethernet Adapter - Virtual Switch)]:64692"
+// clean up IP in case if it is ipv6 address and it has {zone} information in it, like "[fe80::d806:a55d:eb1b:49cc%vEthernet (vmxnet3 Ethernet Adapter - Virtual Switch)]:64692"
 func ipv6fix(clientIP string) string {
 	return strings.Split(clientIP, "%")[0]
 }

memmetrics/anomaly.go

@@ -40,7 +40,7 @@ func SplitRatios(values []float64) (good map[float64]bool, bad map[float64]bool)
 }
 
 // SplitFloat64 provides simple anomaly detection for skewed data sets with no particular distribution.
-// In essense it applies the formula if(v > median(values) + threshold * medianAbsoluteDeviation) -> anomaly
+// In essence it applies the formula if(v > median(values) + threshold * medianAbsoluteDeviation) -> anomaly
 // There's a corner case where there are just 2 values, so by definition there's no value that exceeds the threshold.
 // This case is solved by introducing additional value that we know is good, e.g. 0. That helps to improve the detection results
 // on such data sets.

memmetrics/counter.go

@@ -71,9 +71,7 @@ func (c *RollingCounter) Clone() *RollingCounter {
 		lastBucket:  c.lastBucket,
 		lastUpdated: c.lastUpdated,
 	}
-	for i, v := range c.values {
-		other.values[i] = v
-	}
+	copy(other.values, c.values)
 	return other
 }
 

memmetrics/histogram.go

@@ -179,8 +179,8 @@ func (r *RollingHDRHistogram) Merged() (*HDRHistogram, error) {
 		return m, err
 	}
 	for _, h := range r.buckets {
-		if m.Merge(h); err != nil {
-			return nil, err
+		if errMerge := m.Merge(h); errMerge != nil {
+			return nil, errMerge
 		}
 	}
 	return m, nil

memmetrics/roundtrip.go

@@ -135,7 +135,7 @@ func (m *RTMetrics) CounterWindowSize() time.Duration {
 }
 
 // GetNetworkErrorRatio calculates the amont of network errors such as time outs and dropped connection
-// that occured in the given time window compared to the total requests count.
+// that occurred in the given time window compared to the total requests count.
 func (m *RTMetrics) NetworkErrorRatio() float64 {
 	if m.total.Count() == 0 {
 		return 0
@@ -246,11 +246,6 @@ func (m *RTMetrics) Reset() {
 	m.statusCodes = make(map[int]*RollingCounter)
 }
 
-func (m *RTMetrics) recordNetError() error {
-	m.netErrors.Inc(1)
-	return nil
-}
-
 func (m *RTMetrics) recordLatency(d time.Duration) error {
 	m.histogramLock.Lock()
 	defer m.histogramLock.Unlock()

ratelimit/bucket_test.go

@@ -172,7 +172,7 @@ func (s *BucketSuite) TestUpdateInvalidPeriod(c *C) {
 
 	// ...check that burst did not change
 	s.clock.Sleep(40 * time.Second)
-	delay, err = tb.consume(21)
+	_, err = tb.consume(21)
 	c.Assert(err, NotNil)
 	delay, err = tb.consume(20)
 	c.Assert(err, IsNil)
@@ -216,6 +216,7 @@ func (s *BucketSuite) TestUpdateRateChanged(c *C) {
 	tb.consume(15) // 5 tokens available
 	// When
 	err := tb.update(&rate{time.Second, 20, 20}) // still 5 tokens available
+	c.Assert(err, IsNil)
 	// Then
 	delay, err := tb.consume(20)
 	c.Assert(err, IsNil)

ratelimit/tokenlimiter_test.go

@@ -96,7 +96,7 @@ func (s *LimiterSuite) TestFailure(c *C) {
 	c.Assert(re.StatusCode, Equals, http.StatusInternalServerError)
 }
 
-// Make sure rates from different ips are controlled separatedly
+// Make sure rates from different ips are controlled separately
 func (s *LimiterSuite) TestIsolation(c *C) {
 	handler := http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
 		w.Write([]byte("hello"))

stream/stream.go

@@ -44,7 +44,7 @@ const (
 )
 
 // Stream is responsible for buffering requests and responses
-// It buffers large reqeuests and responses to disk,
+// It buffers large requests and responses to disk,
 type Stream struct {
 	maxRequestBodyBytes int64
 

stream/stream_test.go

@@ -13,9 +13,10 @@ import (
 	"github.com/vulcand/oxy/forward"
 	"github.com/vulcand/oxy/testutils"
 
+	"time"
+
 	log "github.com/sirupsen/logrus"
 	. "gopkg.in/check.v1"
-	"time"
 )
 
 func TestStream(t *testing.T) { TestingT(t) }
@@ -107,10 +108,11 @@ func (s *STSuite) TestChunkedEncodingSuccess(c *C) {
 
 	conn, err := net.Dial("tcp", testutils.ParseURI(proxy.URL).Host)
 	c.Assert(err, IsNil)
-	fmt.Fprintf(conn, "POST / HTTP/1.1\r\nHost: 127.0.0.1\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ntest\r\n5\r\ntest1\r\n5\r\ntest2\r\n0\r\n\r\n")
+	fmt.Fprint(conn, "POST / HTTP/1.1\r\nHost: 127.0.0.1\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ntest\r\n5\r\ntest1\r\n5\r\ntest2\r\n0\r\n\r\n")
 	reader := bufio.NewReader(conn)
 
 	status, err := reader.ReadString('\n')
+	c.Assert(err, IsNil)
 
 	reader.ReadString('\n') //content type
 	reader.ReadString('\n') //Date

testutils/utils.go

@@ -2,7 +2,7 @@ package testutils
 
 import (
 	"crypto/tls"
-	"fmt"
+	"errors"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
@@ -13,7 +13,7 @@ import (
 )
 
 func NewHandler(handler http.HandlerFunc) *httptest.Server {
-	return httptest.NewServer(http.HandlerFunc(handler))
+	return httptest.NewServer(handler)
 }
 
 func NewResponder(response string) *httptest.Server {
@@ -101,7 +101,7 @@ func MakeRequest(url string, opts ...ReqOption) (*http.Response, []byte, error)
 	}
 
 	if o.Method == "" {
-		o.Method = "GET"
+		o.Method = http.MethodGet
 	}
 	request, _ := http.NewRequest(o.Method, url, strings.NewReader(o.Body))
 	if o.Headers != nil {
@@ -131,18 +131,18 @@ func MakeRequest(url string, opts ...ReqOption) (*http.Response, []byte, error)
 	client := &http.Client{
 		Transport: tr,
 		CheckRedirect: func(req *http.Request, via []*http.Request) error {
-			return fmt.Errorf("No redirects")
+			return errors.New("no redirects")
 		},
 	}
 	response, err := client.Do(request)
 	if err == nil {
-		bodyBytes, err := ioutil.ReadAll(response.Body)
-		return response, bodyBytes, err
+		bodyBytes, errRead := ioutil.ReadAll(response.Body)
+		return response, bodyBytes, errRead
 	}
 	return response, nil, err
 }
 
 func Get(url string, opts ...ReqOption) (*http.Response, []byte, error) {
-	opts = append(opts, Method("GET"))
+	opts = append(opts, Method(http.MethodGet))
 	return MakeRequest(url, opts...)
 }

trace/trace_test.go

@@ -104,8 +104,9 @@ func (s *TraceSuite) TestTraceTLS(c *C) {
 	conn, err := tls.Dial("tcp", u.Host, config)
 	c.Assert(err, IsNil)
 
-	fmt.Fprintf(conn, "GET / HTTP/1.0\r\n\r\n")
+	fmt.Fprint(conn, "GET / HTTP/1.0\r\n\r\n")
 	status, err := bufio.NewReader(conn).ReadString('\n')
+	c.Assert(err, IsNil)
 	c.Assert(status, Equals, "HTTP/1.0 200 OK\r\n")
 	state := conn.ConnectionState()
 	conn.Close()

utils/auth.go

@@ -22,18 +22,18 @@ func ParseAuthHeader(header string) (*BasicAuth, error) {
 		return nil, fmt.Errorf(fmt.Sprintf("Failed to parse header '%s'", header))
 	}
 
-	auth_type := strings.ToLower(values[0])
-	if auth_type != "basic" {
-		return nil, fmt.Errorf("Expected basic auth type, got '%s'", auth_type)
+	authType := strings.ToLower(values[0])
+	if authType != "basic" {
+		return nil, fmt.Errorf("Expected basic auth type, got '%s'", authType)
 	}
 
-	encoded_string := values[1]
-	decoded_string, err := base64.StdEncoding.DecodeString(encoded_string)
+	encodedString := values[1]
+	decodedString, err := base64.StdEncoding.DecodeString(encodedString)
 	if err != nil {
 		return nil, fmt.Errorf("Failed to parse header '%s', base64 failed: %s", header, err)
 	}
 
-	values = strings.SplitN(string(decoded_string), ":", 2)
+	values = strings.SplitN(string(decodedString), ":", 2)
 	if len(values) != 2 {
 		return nil, fmt.Errorf("Failed to parse header '%s', expected separator ':'", header)
 	}