Show specific error messages on errors creating the tunnel. Fixes #972

cmd/cloudflared/tunnel/quick_tunnel.go

@@ -3,6 +3,7 @@ package tunnel
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -47,9 +48,23 @@ func RunQuickTunnel(sc *subcommandContext) error {
 	}
 	defer resp.Body.Close()
 
+	// Report sensible errors rather than just failing to parse the non-JSON body
+	if resp.StatusCode == http.StatusTooManyRequests {
+		return errors.New("rate limit exceeded; wait a while and try again")
+	} else if resp.StatusCode != http.StatusOK {
+		return errors.New(fmt.Sprintf("HTTP error %d", resp.StatusCode))
+	}
+
+	// Need to read the body, so we can include it in the error if we fail to parse it
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return errors.Wrap(err, "error reading HTTP response")
+	}
+
 	var data QuickTunnelResponse
-	if err := json.NewDecoder(resp.Body).Decode(&data); err != nil {
-		return errors.Wrap(err, "failed to unmarshal quick Tunnel")
+	if err := json.Unmarshal(body, &data); err != nil {
+		message := fmt.Sprintf("failed to unmarshal quick Tunnel \"%v\"", string(body))
+		return errors.Wrap(err, message)
 	}
 
 	tunnelID, err := uuid.Parse(data.Result.ID)

cmd/cloudflared/tunnel/quick_tunnel_test.go

@@ -0,0 +1,109 @@
+package tunnel
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"github.com/cloudflare/cloudflared/cmd/cloudflared/cliutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/urfave/cli/v2"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func makeContext(i int, serverUrl string) *cli.Context {
+	flagSet := flag.NewFlagSet(fmt.Sprintf("test%d", i), flag.PanicOnError)
+	flagSet.String("edge-ip-version", "", "")
+	flagSet.String("protocol", "", "")
+	flagSet.String("url", "", "")
+	flagSet.String("quick-service", "", "")
+
+	c := cli.NewContext(cli.NewApp(), flagSet, nil)
+	_ = c.Set("edge-ip-version", "auto")
+	_ = c.Set("protocol", "quic")
+	_ = c.Set("url", "http://localhost:8080")
+	_ = c.Set("quick-service", serverUrl)
+	return c
+}
+
+// @noinspection SpellCheckingInspection
+func TestQuickTunnel(t *testing.T) {
+	var tests = []struct {
+		name        string
+		statusCode  int
+		response    string
+		wantErr     bool
+		expectedErr error
+	}{
+		{
+			name:       "200 OK response from server, valid response",
+			statusCode: http.StatusOK,
+			response:   `{"success":true,"result":{"id":"0347c3ea-504b-47bc-8e2c-339961e6ea3e","name":"qt-not-a-real-name","hostname":"not-a-real-hostname.trycloudflare.com","account_tag":"not-an-account-tag","secret":"notreallyasecret"},"errors":[]}`,
+		},
+		{
+			name:        "200 OK response from server, bad tunnel ID",
+			statusCode:  http.StatusOK,
+			response:    `{"success":true,"result":{"id":"not-a-uuid","name":"qt-not-a-real-name","hostname":"not-a-real-hostname.trycloudflare.com","account_tag":"not-an-account-tag","secret":"notreallyasecret"},"errors":[]}`,
+			wantErr:     true,
+			expectedErr: errors.New("failed to parse quick Tunnel ID: invalid UUID length: 10"),
+		},
+		{
+			name:        "200 OK response from server, bad JSON",
+			statusCode:  http.StatusOK,
+			response:    `This is not JSON!`,
+			wantErr:     true,
+			expectedErr: errors.New("failed to unmarshal quick Tunnel \"This is not JSON!\": invalid character 'T' looking for beginning of value"),
+		},
+		{
+			name:        "429 Too Many Requests response from server",
+			statusCode:  http.StatusTooManyRequests,
+			response:    `error`,
+			wantErr:     true,
+			expectedErr: errors.New("rate limit exceeded; wait a while and try again"),
+		},
+		{
+			name:        "400 Bad Request response from server",
+			statusCode:  http.StatusBadRequest,
+			response:    `error`,
+			wantErr:     true,
+			expectedErr: errors.New("HTTP error 400"),
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Initialize tunnel subcommand
+			bInfo := cliutil.GetBuildInfo("", "DEV")
+			graceShutdownC := make(chan struct{})
+			Init(bInfo, graceShutdownC)
+
+			// Create a test HTTP server to act in place of the Cloudflare service
+			serverReceivedRequest := false
+			server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+				// All requests should be to /tunnel
+				assert.Equal(t, "/tunnel", req.URL.String())
+
+				serverReceivedRequest = true
+
+				rw.WriteHeader(tt.statusCode)
+				_, _ = rw.Write([]byte(tt.response))
+			}))
+			defer server.Close()
+
+			if !tt.wantErr {
+				// Close the shutdown channel now so that the tunnel subcommand doesn't proceed to the quic negotiation
+				close(graceShutdownC)
+			}
+
+			err := TunnelCommand(makeContext(i, server.URL))
+
+			if tt.wantErr {
+				assert.Equal(t, tt.expectedErr.Error(), err.Error())
+			} else {
+				assert.Nil(t, err)
+			}
+			assert.True(t, serverReceivedRequest)
+		})
+	}
+}