1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
package staticpages
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"path/filepath"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
"gitlab.com/gitlab-org/gitlab-workhorse/internal/helper"
)
var (
staticErrorResponses = promauto.NewCounterVec(
prometheus.CounterOpts{
Name: "gitlab_workhorse_static_error_responses",
Help: "How many HTTP responses have been changed to a static error page, by HTTP status code.",
},
[]string{"code"},
)
)
type ErrorFormat int
const (
ErrorFormatHTML ErrorFormat = iota
ErrorFormatJSON
ErrorFormatText
)
type errorPageResponseWriter struct {
rw http.ResponseWriter
status int
hijacked bool
path string
format ErrorFormat
}
func (s *errorPageResponseWriter) Header() http.Header {
return s.rw.Header()
}
func (s *errorPageResponseWriter) Write(data []byte) (int, error) {
if s.status == 0 {
s.WriteHeader(http.StatusOK)
}
if s.hijacked {
return len(data), nil
}
return s.rw.Write(data)
}
func (s *errorPageResponseWriter) WriteHeader(status int) {
if s.status != 0 {
return
}
s.status = status
if s.status < 400 || s.status > 599 || s.rw.Header().Get("X-GitLab-Custom-Error") != "" {
s.rw.WriteHeader(status)
return
}
var contentType string
var data []byte
switch s.format {
case ErrorFormatText:
contentType, data = s.writeText()
case ErrorFormatJSON:
contentType, data = s.writeJSON()
default:
contentType, data = s.writeHTML()
}
if contentType == "" {
s.rw.WriteHeader(status)
return
}
s.hijacked = true
staticErrorResponses.WithLabelValues(fmt.Sprintf("%d", s.status)).Inc()
helper.SetNoCacheHeaders(s.rw.Header())
s.rw.Header().Set("Content-Type", contentType)
s.rw.Header().Set("Content-Length", fmt.Sprintf("%d", len(data)))
s.rw.Header().Del("Transfer-Encoding")
s.rw.WriteHeader(s.status)
s.rw.Write(data)
}
func (s *errorPageResponseWriter) writeHTML() (string, []byte) {
if s.rw.Header().Get("Content-Type") != "application/json" {
errorPageFile := filepath.Join(s.path, fmt.Sprintf("%d.html", s.status))
// check if custom error page exists, serve this page instead
if data, err := ioutil.ReadFile(errorPageFile); err == nil {
return "text/html; charset=utf-8", data
}
}
return "", nil
}
func (s *errorPageResponseWriter) writeJSON() (string, []byte) {
message, err := json.Marshal(map[string]interface{}{"error": http.StatusText(s.status), "status": s.status})
if err != nil {
return "", nil
}
return "application/json; charset=utf-8", append(message, "\n"...)
}
func (s *errorPageResponseWriter) writeText() (string, []byte) {
return "text/plain; charset=utf-8", []byte(http.StatusText(s.status) + "\n")
}
func (s *errorPageResponseWriter) flush() {
s.WriteHeader(http.StatusOK)
}
func (st *Static) ErrorPagesUnless(disabled bool, format ErrorFormat, handler http.Handler) http.Handler {
if disabled {
return handler
}
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
rw := errorPageResponseWriter{
rw: w,
path: st.DocumentRoot,
format: format,
}
defer rw.flush()
handler.ServeHTTP(&rw, r)
})
}
|
