package badgateway
import (
"bytes"
"fmt"
"html/template"
"io/ioutil"
"net/http"
"strings"
"time"
"gitlab.com/gitlab-org/labkit/log"
"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
)
// 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)}
helper.LogErrorWithFields(
r,
&sentryError{fmt.Errorf("badgateway: failed to receive response: %v", err)},
fields,
)
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 = ioutil.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,
}
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
}
var developmentErrorTemplate = template.Must(template.New("error502").Parse(`
502: GitLab is not responding
502
GitLab is not responding. The error was:
{{.Error}}
If you just started GDK it can take 60-300 seconds before GitLab has finished booting. This page will automatically reload every {{.ReloadSeconds}} seconds.