dumping har logs to file

cmd/proxy/main.go

@@ -194,6 +194,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"flag"
+	"fmt"
 	"log"
 	"net"
 	"net/http"
@@ -247,6 +248,7 @@ var (
 	validity       = flag.Duration("validity", time.Hour, "window of time that MITM certificates are valid")
 	allowCORS      = flag.Bool("cors", false, "allow CORS requests to configure the proxy")
 	harLogging     = flag.Bool("har", false, "enable HAR logging API")
+	harFile        = flag.String("harFile", "./martian.har", "har file path")
 	marblLogging   = flag.Bool("marbl", false, "enable MARBL logging API")
 	trafficShaping = flag.Bool("traffic-shaping", false, "enable traffic shaping API")
 	skipTLSVerify  = flag.Bool("skip-tls-verify", false, "skip TLS server verification; insecure")
@@ -389,6 +391,7 @@ func main() {
 
 		configure("/logs", har.NewExportHandler(hl), mux)
 		configure("/logs/reset", har.NewResetHandler(hl), mux)
+		configure("/logs/dump", har.NewDumpHandler(hl, *harFile), mux)
 	}
 
 	logger := martianlog.NewLogger()
@@ -442,6 +445,18 @@ func main() {
 
 	<-sigc
 
+	if *harLogging {
+		log.Println("martian: dumping har file")
+		u := url.URL{}
+		proxy, _ := u.Parse(fmt.Sprintf("http://%v", *addr))
+		transport := http.Transport{}
+		transport.Proxy = http.ProxyURL(proxy) // set proxy
+
+		client := &http.Client{}
+		client.Transport = &transport
+		client.Get("http://martian.proxy/logs/dump")
+	}
+
 	log.Println("martian: shutting down")
 	os.Exit(0)
 }

har/har_handlers.go

@@ -16,8 +16,11 @@ package har
 
 import (
 	"encoding/json"
+	"io"
 	"net/http"
 	"net/url"
+	"os"
+	"path/filepath"
 	"strconv"
 
 	"github.com/google/martian/v3/log"
@@ -31,6 +34,11 @@ type resetHandler struct {
 	logger *Logger
 }
 
+type dumpHandler struct {
+	logger   *Logger
+	filePath string
+}
+
 // NewExportHandler returns an http.Handler for requesting HAR logs.
 func NewExportHandler(l *Logger) http.Handler {
 	return &exportHandler{
@@ -45,6 +53,61 @@ func NewResetHandler(l *Logger) http.Handler {
 	}
 }
 
+// NewDumpHandler returns an http.Handler for dumping log entries to file.
+func NewDumpHandler(l *Logger, path string) http.Handler {
+	return &dumpHandler{
+		logger:   l,
+		filePath: path,
+	}
+}
+
+type fileResponseWriter struct {
+	file  io.Writer
+	multi io.Writer
+}
+
+func (w *fileResponseWriter) Write(b []byte) (int, error) {
+	return w.multi.Write(b)
+}
+
+func newFileResponseWriter(file io.Writer) io.Writer {
+	multi := io.MultiWriter(file)
+	return &fileResponseWriter{
+		file:  file,
+		multi: multi,
+	}
+}
+
+func (h *dumpHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	if req.Method != "GET" {
+		rw.Header().Add("Allow", "GET")
+		rw.WriteHeader(http.StatusMethodNotAllowed)
+		log.Errorf("har.ServeHTTP: method not allowed: %s", req.Method)
+		return
+	}
+	log.Debugf("exportHandler.ServeHTTP: writing HAR logs to ResponseWriter")
+	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
+
+	dir := filepath.Dir(h.filePath)
+	err := os.MkdirAll(dir, 0764)
+	if err != nil {
+		log.Errorf("mkdir", err)
+	}
+
+	file, err := os.Create(h.filePath)
+	defer file.Close()
+	if err != nil {
+		log.Errorf("create file", err)
+		return
+	}
+
+	writer := newFileResponseWriter(file)
+	hl := h.logger.Export()
+	encoder := json.NewEncoder(writer)
+	encoder.SetIndent("", "\t")
+	encoder.Encode(hl)
+}
+
 // ServeHTTP writes the log in HAR format to the response body.
 func (h *exportHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	if req.Method != "GET" {
@@ -70,7 +133,6 @@ func (h *resetHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-
 	v, err := parseBoolQueryParam(req.URL.Query(), "return")
 	if err != nil {
 		log.Errorf("har: invalid value for return param: %s", err)