chore(go): update code to pass golangci-lint (#23)

Author: joshdk

.golangci.yml

@@ -0,0 +1,18 @@
+linters:
+  enable-all: true
+  disable:
+    - cyclop
+    - exhaustive
+    - exhaustivestruct
+    - funlen
+    - golint
+    - interfacer
+    - lll
+    - maligned
+    - nlreturn
+    - scopelint
+    - wrapcheck
+    - wsl
+
+issues:
+  exclude-use-default: true

analytics/title.go

@@ -18,7 +18,7 @@ import (
 func getTitle(recorder *httptest.ResponseRecorder) (title string, err error) {
 	// The content type that was returned. The <title> tag can only be
 	// extracted from an HTML response body.
-	var contentType = recorder.Header().Get("Content-Type")
+	contentType := recorder.Header().Get("Content-Type")
 
 	// Only bother parsing HTML if there is HTML to parse.
 	if !strings.Contains(contentType, "text/html") {
@@ -28,7 +28,7 @@ func getTitle(recorder *httptest.ResponseRecorder) (title string, err error) {
 	// The content encoding that was returned. The response body may be be
 	// compressed, so detect the type of compression, if any, and decode the
 	// response body accordingly.
-	var contentEncoding = recorder.Header().Get("Content-Encoding")
+	contentEncoding := recorder.Header().Get("Content-Encoding")
 	var reader io.Reader = bytes.NewBuffer(recorder.Body.Bytes())
 
 	// How is the request compressed?

analytics/tracker.go

@@ -5,12 +5,14 @@
 package analytics
 
 import (
+	"context"
 	"io"
 	"log"
 	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"time"
 )
 
 // Compile-time assertion that Tracker implements http.Handler.
@@ -58,7 +60,7 @@ func (t *Tracker) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 		// Copy status code.
 		writer.WriteHeader(recorder.Code)
 		// Copy response body.
-		io.Copy(writer, recorder.Body)
+		_, _ = io.Copy(writer, recorder.Body)
 	}()
 
 	// Set values for the various Google Analytics request query parameters.
@@ -114,7 +116,7 @@ func (t *Tracker) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	// Fallback to using the IP address of the client connection itself, which
 	// may be inaccurate (or in a private address range) depending on your
 	// networking configuration.
-	//See: https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters#uip
+	// See: https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters#uip
 	if value := request.Header.Get("X-Forwarded-For"); value != "" {
 		params.Set("uip", value)
 	} else if value, _, err := net.SplitHostPort(request.RemoteAddr); err == nil {
@@ -190,8 +192,32 @@ func (t *Tracker) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
 	// regardless of the request. We also only log an error in order to not
 	// interrupt responses back to the client.
 	go func() {
-		if _, err := http.DefaultClient.Get(googleAnalytics.String()); err != nil {
+		if err := report(googleAnalytics.String()); err != nil {
 			log.Printf("error: %v", err)
 		}
 	}()
 }
+
+func report(url string) error {
+	// googleAnalyticsTimeout is a (rather short) timeout used when sending
+	// requests to Google Analytics.
+	const googleAnalyticsTimeout = time.Second * 5
+
+	// Create, and automatically cancel, a context using the above timeout.
+	ctx, cancel := context.WithTimeout(context.Background(), googleAnalyticsTimeout)
+	defer cancel()
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return err
+	}
+
+	// Send report to Google Analytics.
+	response, err := http.DefaultClient.Do(request)
+	if err != nil {
+		return err
+	}
+	_ = response.Body.Close()
+
+	return nil
+}

main.go

@@ -22,7 +22,7 @@ var version = "development"
 
 func main() {
 	if err := mainCmd(); err != nil {
-		fmt.Printf("google-analytics-proxy: %v", err)
+		fmt.Printf("google-analytics-proxy: %v", err) //nolint:forbidigo
 		os.Exit(1)
 	}
 }
@@ -33,37 +33,37 @@ func mainCmd() error {
 	// listenAddress is the host and port that the proxy will listen on.
 	// See net.Dial for details of the address format.
 	// Example: "localhost:8080" "0.0.0.0:8080" ":8080"
-	var listenAddress = os.Getenv("LISTEN")
+	listenAddress := os.Getenv("LISTEN")
 
 	// upstreamEndpoint is the address of the upstream service to be
 	// proxied.
 	// Example: "https://example.com" "http://:80"
-	var upstreamEndpoint = os.Getenv("UPSTREAM_ENDPOINT")
+	upstreamEndpoint := os.Getenv("UPSTREAM_ENDPOINT")
 
 	// upstreamHostname optionally is the hostname to used when proxying
 	// requests to the upstream. Used for hostname based routing. If empty, the
 	// value of $GOOGLE_ANALYTICS_PROPERTY_NAME will be used.
 	// Example: "example.com"
-	var upstreamHostname = os.Getenv("UPSTREAM_HOSTNAME")
+	upstreamHostname := os.Getenv("UPSTREAM_HOSTNAME")
 
 	// googleAnalyticsTrackingID is the tracking id for the Google
 	// Analytics property that you want to track pageview events for. This
 	// can be found in your Google Analytics dashboard.
 	// Example: "UA-123456789-1"
-	var googleAnalyticsTrackingID = os.Getenv("GOOGLE_ANALYTICS_TRACKING_ID")
+	googleAnalyticsTrackingID := os.Getenv("GOOGLE_ANALYTICS_TRACKING_ID")
 
 	// googleAnalyticsPropertyName is the name for the Google Analytics
 	// property that you want to track pageview events for. This can be
 	// found in your Google Analytics dashboard. Will be used as the upstream
 	// hostname in proxied requests if $UPSTREAM_HOSTNAME is empty.
 	// Example: "example.com"
-	var googleAnalyticsPropertyName = os.Getenv("GOOGLE_ANALYTICS_PROPERTY_NAME")
+	googleAnalyticsPropertyName := os.Getenv("GOOGLE_ANALYTICS_PROPERTY_NAME")
 
 	// googleAnalyticsDryRun can optionally be used to disable reporting
 	// pageview events with Google Analytics. See strconv.ParseBool() for
 	// acceptable values.
 	// Example: "true"
-	var googleAnalyticsDryRun = os.Getenv("GOOGLE_ANALYTICS_DRY_RUN")
+	googleAnalyticsDryRun := os.Getenv("GOOGLE_ANALYTICS_DRY_RUN")
 
 	// Parse the upstream endpoint address to ensure that it's valid.
 	upstreamURL, err := url.Parse(upstreamEndpoint)