package badgateway import ( "bytes" _ "embed" "encoding/base64" "fmt" "html/template" "io" "net/http" "strings" "time" "gitlab.com/gitlab-org/gitlab/workhorse/internal/log" ) //go:embed embed/gitlab-logo-500.png var gitlabLogo []byte // Error is a custom error for pretty Sentry 'issues' type sentryError struct{ error } type roundTripper struct { next http.RoundTripper developmentMode bool } // NewRoundTripper creates a RoundTripper with a provided underlying next transport func NewRoundTripper(developmentMode bool, next http.RoundTripper) http.RoundTripper { return &roundTripper{next: next, developmentMode: developmentMode} } func (t *roundTripper) RoundTrip(r *http.Request) (*http.Response, error) { start := time.Now() res, err := t.next.RoundTrip(r) if err == nil { return res, err } // httputil.ReverseProxy translates all errors from this // RoundTrip function into 500 errors. But the most likely error // is that the Rails app is not responding, in which case users // and administrators expect to see a 502 error. To show 502s // instead of 500s we catch the RoundTrip error here and inject a // 502 response. fields := log.Fields{"duration_ms": int64(time.Since(start).Seconds() * 1000)} log.WithRequest(r).WithFields(fields).WithError(&sentryError{fmt.Errorf("badgateway: failed to receive response: %v", err)}).Error() injectedResponse := &http.Response{ StatusCode: http.StatusBadGateway, Status: http.StatusText(http.StatusBadGateway), Request: r, ProtoMajor: r.ProtoMajor, ProtoMinor: r.ProtoMinor, Proto: r.Proto, Header: make(http.Header), Trailer: make(http.Header), } message := "GitLab is not responding" contentType := "text/plain" if t.developmentMode { message, contentType = developmentModeResponse(err) } injectedResponse.Body = io.NopCloser(strings.NewReader(message)) injectedResponse.Header.Set("Content-Type", contentType) return injectedResponse, nil } func developmentModeResponse(err error) (body string, contentType string) { data := TemplateData{ Time: time.Now().Format("15:04:05"), Error: err.Error(), ReloadSeconds: 5, Base64EncodedGitLabLogo: base64.StdEncoding.EncodeToString(gitlabLogo), } buf := &bytes.Buffer{} if err := developmentErrorTemplate.Execute(buf, data); err != nil { return data.Error, "text/plain" } return buf.String(), "text/html" } type TemplateData struct { Time string Error string ReloadSeconds int Base64EncodedGitLabLogo string } var developmentErrorTemplate = template.Must(template.New("error502").Parse(` Waiting for GitLab to boot
GitLab

Waiting for GitLab to boot

{{.Error}}

It can take 60-180 seconds for GitLab to boot completely.

This page will automatically reload every {{.ReloadSeconds}} seconds.


`))