/
backend.go
135 lines (113 loc) · 2.92 KB
/
backend.go
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
package main
import (
"bytes"
"context"
"embed"
"encoding/json"
"errors"
"fmt"
"io"
"log"
"net"
"net/http"
"os"
"path"
"syscall"
"time"
"golang.org/x/sync/errgroup"
)
//go:embed *.html
var BackendFS embed.FS
func (c *ServeBackendCmd) Run(p *ProgramCtx) error {
log.SetPrefix(fmt.Sprintf("[c %v %v %s] ", os.Getpid(), mustResolveHostIP(), c.Name))
var t = mustParseTrafficType(string(c.TrafficType))
listenAddress := c.ListenAddress
if listenAddress == "" || listenAddress == "127.0.0.1" || listenAddress == "::1" {
listenAddress = "0.0.0.0"
}
listener, err := net.Listen("tcp", fmt.Sprintf("%v:0", listenAddress))
if err != nil {
return err
}
certs := certStore(path.Join(p.Globals.OutputDir, "certs"))
httpServer := &http.Server{
Handler: http.FileServer(http.FS(BackendFS)),
Addr: fmt.Sprintf("%v:%v", listenAddress, p.Port),
ReadTimeout: 15 * time.Second,
WriteTimeout: 15 * time.Second,
}
g, gCtx := errgroup.WithContext(p.Context)
g.Go(func() error {
switch t {
case HTTPTraffic, EdgeTraffic:
return httpServer.Serve(listener)
default:
return httpServer.ServeTLS(listener, certs.DomainFile, certs.TLSKeyFile)
}
})
g.Go(func() error {
<-gCtx.Done()
httpServer.SetKeepAlivesEnabled(false)
shutdownCtx, shutdownRelease := context.WithTimeout(context.Background(), httpServer.WriteTimeout)
defer shutdownRelease()
return httpServer.Shutdown(shutdownCtx)
})
if listenAddress == "0.0.0.0" {
listenAddress = mustResolveHostIP()
}
boundBackend := BoundBackend{
Backend: Backend{
Name: c.Name,
TrafficType: t,
},
ListenAddress: listenAddress,
Port: listener.Addr().(*net.TCPAddr).Port,
}
jsonValue, err := json.Marshal(boundBackend)
if err != nil {
return err
}
var (
resp *http.Response
retries = 17
)
client := &http.Client{
Timeout: 10 * time.Second,
}
url := fmt.Sprintf("http://127.0.0.1:%d/register", p.Port)
for {
request, err := http.NewRequest(http.MethodPost, url, bytes.NewBuffer(jsonValue))
if err != nil {
return err
}
request.Header.Set("Content-Type", "application/json; charset=UTF-8")
request.Close = true
if resp, err = client.Do(request); err == nil {
break
}
if errors.Is(err, syscall.ECONNREFUSED) {
// Perhaps the parent crashed (e.g., cannot
// spawn OS thread due to lack of resources,
// or other). If we cannot connect there's no
// point retrying.
return fmt.Errorf("%s: %w", url, err)
}
retries -= 1
if retries == 0 {
return fmt.Errorf("backend registration %+v failed: %v", boundBackend, err)
}
time.Sleep(250 * time.Millisecond)
}
_, err = io.ReadAll(resp.Body)
defer resp.Body.Close()
if err != nil {
return err
}
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("registration failed for %+v; Status=%v", boundBackend, resp.Status)
}
if err := g.Wait(); err != nil && !errors.Is(err, http.ErrServerClosed) {
return err
}
return nil
}