package customerrors import ( "context" "fmt" "net/http" "net/http/httptest" "testing" "github.com/stretchr/testify/assert" "github.com/stretchr/testify/require" "github.com/traefik/traefik/v3/pkg/config/dynamic" "github.com/traefik/traefik/v3/pkg/testhelpers" ) func TestHandler(t *testing.T) { testCases := []struct { desc string errorPage *dynamic.ErrorPage backendCode int backendErrorHandler http.HandlerFunc validate func(t *testing.T, recorder *httptest.ResponseRecorder) }{ { desc: "no error", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"500-501", "503-599"}}, backendCode: http.StatusOK, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, "My error page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusOK, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), http.StatusText(http.StatusOK)) }, }, { desc: "no error, but not a 200", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"500-501", "503-599"}}, backendCode: http.StatusPartialContent, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, "My error page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusPartialContent, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), http.StatusText(http.StatusPartialContent)) }, }, { desc: "a 304, so no Write called", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"500-501", "503-599"}}, backendCode: http.StatusNotModified, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, "whatever, should not be called") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusNotModified, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "") }, }, { desc: "in the range", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"500-501", "503-599"}}, backendCode: http.StatusInternalServerError, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, "My error page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusInternalServerError, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "My error page.") }, }, { desc: "not in the range", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"500-501", "503-599"}}, backendCode: http.StatusBadGateway, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, "My error page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusBadGateway, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), http.StatusText(http.StatusBadGateway)) }, }, { desc: "query replacement", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/{status}", Status: []string{"503-503"}}, backendCode: http.StatusServiceUnavailable, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.RequestURI != "/503" { return } _, _ = fmt.Fprintln(w, "My 503 page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusServiceUnavailable, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "My 503 page.") }, }, { desc: "single code and query replacement", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/{status}", Status: []string{"503"}}, backendCode: http.StatusServiceUnavailable, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.RequestURI != "/503" { return } _, _ = fmt.Fprintln(w, "My 503 page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusServiceUnavailable, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "My 503 page.") }, }, { desc: "forward request host header", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/test", Status: []string{"503"}}, backendCode: http.StatusServiceUnavailable, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = fmt.Fprintln(w, r.Host) }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusServiceUnavailable, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "localhost") }, }, { desc: "full query replacement", errorPage: &dynamic.ErrorPage{Service: "error", Query: "/?status={status}&url={url}", Status: []string{"503"}}, backendCode: http.StatusServiceUnavailable, backendErrorHandler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { if r.RequestURI != "/?status=503&url=http%3A%2F%2Flocalhost%2Ftest%3Ffoo%3Dbar%26baz%3Dbuz" { t.Log(r.RequestURI) return } _, _ = fmt.Fprintln(w, "My 503 page.") }), validate: func(t *testing.T, recorder *httptest.ResponseRecorder) { t.Helper() assert.Equal(t, http.StatusServiceUnavailable, recorder.Code, "HTTP status") assert.Contains(t, recorder.Body.String(), "My 503 page.") }, }, } for _, test := range testCases { test := test t.Run(test.desc, func(t *testing.T) { t.Parallel() serviceBuilderMock := &mockServiceBuilder{handler: test.backendErrorHandler} handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(test.backendCode) if test.backendCode == http.StatusNotModified { return } _, _ = fmt.Fprintln(w, http.StatusText(test.backendCode)) }) errorPageHandler, err := New(context.Background(), handler, *test.errorPage, serviceBuilderMock, "test") require.NoError(t, err) req := testhelpers.MustNewRequest(http.MethodGet, "http://localhost/test?foo=bar&baz=buz", nil) recorder := httptest.NewRecorder() errorPageHandler.ServeHTTP(recorder, req) test.validate(t, recorder) }) } } type mockServiceBuilder struct { handler http.Handler } func (m *mockServiceBuilder) BuildHTTP(_ context.Context, _ string) (http.Handler, error) { return m.handler, nil }