Log POST payload in WFE. (#2772)

This allows us to look at logs in more detail.

Also, remove RequestNonce, ResponseNonce, and ClientAddr, which we don't use and
take up log space. And set "Errors" to "omitempty."

Fixes #2747.

wfe/context.go

@@ -13,19 +13,19 @@ import (
 )
 
 type requestEvent struct {
-	ID            string `json:",omitempty"`
-	RealIP        string `json:",omitempty"`
-	ClientAddr    string `json:",omitempty"`
-	Endpoint      string `json:",omitempty"`
-	Method        string `json:",omitempty"`
-	Errors        []string
-	Requester     int64                  `json:",omitempty"`
-	Contacts      *[]string              `json:",omitempty"`
-	RequestNonce  string                 `json:",omitempty"`
-	ResponseNonce string                 `json:",omitempty"`
-	UserAgent     string                 `json:",omitempty"`
-	Extra         map[string]interface{} `json:",omitempty"`
+	ID            string    `json:",omitempty"`
+	RealIP        string    `json:",omitempty"`
+	Endpoint      string    `json:",omitempty"`
+	Method        string    `json:",omitempty"`
+	Errors        []string  `json:",omitempty"`
+	Requester     int64     `json:",omitempty"`
+	Contacts      *[]string `json:",omitempty"`
+	RequestNonce  string    `json:",omitempty"`
+	ResponseNonce string    `json:",omitempty"`
+	UserAgent     string    `json:",omitempty"`
 	Code          int
+	Payload       string                 `json:",omitempty"`
+	Extra         map[string]interface{} `json:",omitempty"`
 }
 
 func (e *requestEvent) AddError(msg string, args ...interface{}) {
@@ -51,12 +51,11 @@ type topHandler struct {
 
 func (th *topHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	logEvent := &requestEvent{
-		ID:         core.NewToken(),
-		RealIP:     r.Header.Get("X-Real-IP"),
-		ClientAddr: getClientAddr(r),
-		Method:     r.Method,
-		UserAgent:  r.Header.Get("User-Agent"),
-		Extra:      make(map[string]interface{}, 0),
+		ID:        core.NewToken(),
+		RealIP:    r.Header.Get("X-Real-IP"),
+		Method:    r.Method,
+		UserAgent: r.Header.Get("User-Agent"),
+		Extra:     make(map[string]interface{}, 0),
 	}
 	w.Header().Set("Boulder-Request-ID", logEvent.ID)
 	defer th.logEvent(logEvent)

wfe/wfe.go

@@ -552,6 +552,7 @@ func (wfe *WebFrontEndImpl) verifyPOST(ctx context.Context, logEvent *requestEve
 		logEvent.AddError("verification of JWS with the JWK failed: %v; body: %s", err, body[:n])
 		return nil, nil, reg, probs.Malformed("JWS verification error")
 	}
+	logEvent.Payload = string(payload)
 
 	// Check that the request has a known anti-replay nonce
 	nonce := parsedJws.Signatures[0].Header.Nonce

wfe/wfe_test.go

@@ -1797,11 +1797,9 @@ func TestGetCertificate(t *testing.T) {
 		t, responseWriter.Header().Get("Link"),
 		`<https://localhost:4000/acme/issuer-cert>;rel="up"`)
 
-	t.Logf("UGH %#v", mockLog.GetAll()[0])
 	reqlogs := mockLog.GetAllMatching(`Successful request`)
 	test.AssertEquals(t, len(reqlogs), 1)
 	test.AssertContains(t, reqlogs[0], `INFO: `)
-	test.AssertContains(t, reqlogs[0], `"ClientAddr":"192.168.0.1"`)
 
 	// Unused serial, no cache
 	mockLog.Clear()
@@ -1817,7 +1815,6 @@ func TestGetCertificate(t *testing.T) {
 	reqlogs = mockLog.GetAllMatching(`Terminated request`)
 	test.AssertEquals(t, len(reqlogs), 1)
 	test.AssertContains(t, reqlogs[0], `INFO: `)
-	test.AssertContains(t, reqlogs[0], `"ClientAddr":"192.168.99.99,192.168.0.1"`)
 
 	// Invalid serial, no cache
 	responseWriter = httptest.NewRecorder()
@@ -1884,6 +1881,21 @@ type mockSADifferentStoredKey struct {
 	core.StorageGetter
 }
 
+// TestLogPayload ensures that verifyPOST sets the Payload field of the logEvent
+// it is passed.
+func TestLogPayload(t *testing.T) {
+	wfe, _ := setupWFE(t)
+	event := newRequestEvent()
+	payload := `{"resource":"ima-payload"}`
+	_, _, _, err := wfe.verifyPOST(ctx, event, makePostRequest(signRequest(t,
+		payload, wfe.nonceService)), false, "ima-payload")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	test.AssertEquals(t, event.Payload, payload)
+}
+
 func (sa mockSADifferentStoredKey) GetRegistrationByKey(ctx context.Context, jwk *jose.JsonWebKey) (core.Registration, error) {
 	keyJSON := []byte(test2KeyPublicJSON)
 	var parsedKey jose.JsonWebKey