/
content.go
121 lines (107 loc) · 3.88 KB
/
content.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
package main
import (
"fmt"
"html/template"
"net/http"
"github.com/free/sql_exporter"
)
const (
docsUrl = "https://github.com/free/sql_exporter#readme"
templates = `
{{ define "page" -}}
<html>
<head>
<title>Prometheus SQL Exporter</title>
<style type="text/css">
body { margin: 0; font-family: "Helvetica Neue", Helvetica, Arial, sans-serif; font-size: 14px; line-height: 1.42857143; color: #333; background-color: #fff; }
.navbar { display: flex; background-color: #222; margin: 0; border-width: 0 0 1px; border-style: solid; border-color: #080808; }
.navbar > * { margin: 0; padding: 15px; }
.navbar * { line-height: 20px; color: #9d9d9d; }
.navbar a { text-decoration: none; }
.navbar a:hover, .navbar a:focus { color: #fff; }
.navbar-header { font-size: 18px; }
body > * { margin: 15px; padding: 0; }
pre { padding: 10px; font-size: 13px; background-color: #f5f5f5; border: 1px solid #ccc; }
h1, h2 { font-weight: 500; }
a { color: #337ab7; }
a:hover, a:focus { color: #23527c; }
</style>
</head>
<body>
<div class="navbar">
<div class="navbar-header"><a href="/">Prometheus SQL Exporter</a></div>
<div><a href="{{ .MetricsPath }}">Metrics</a></div>
<div><a href="/config">Configuration</a></div>
<div><a href="/debug/pprof">Profiling</a></div>
<div><a href="{{ .DocsUrl }}">Help</a></div>
</div>
{{template "content" .}}
</body>
</html>
{{- end }}
{{ define "content.home" -}}
<p>This is a <a href="{{ .DocsUrl }}">Prometheus SQL Exporter</a> instance.
You are probably looking for its <a href="{{ .MetricsPath }}">metrics</a> handler.</p>
{{- end }}
{{ define "content.config" -}}
<h2>Configuration</h2>
<pre>{{ .Config }}</pre>
{{- end }}
{{ define "content.error" -}}
<h2>Error</h2>
<pre>{{ .Err }}</pre>
{{- end }}
`
)
type tdata struct {
MetricsPath string
DocsUrl string
// `/config` only
Config string
// `/error` only
Err error
}
var (
allTemplates = template.Must(template.New("").Parse(templates))
homeTemplate = pageTemplate("home")
configTemplate = pageTemplate("config")
errorTemplate = pageTemplate("error")
)
func pageTemplate(name string) *template.Template {
pageTemplate := fmt.Sprintf(`{{define "content"}}{{template "content.%s" .}}{{end}}{{template "page" .}}`, name)
return template.Must(template.Must(allTemplates.Clone()).Parse(pageTemplate))
}
// HomeHandlerFunc is the HTTP handler for the home page (`/`).
func HomeHandlerFunc(metricsPath string) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
homeTemplate.Execute(w, &tdata{
MetricsPath: metricsPath,
DocsUrl: docsUrl,
})
}
}
// ConfigHandlerFunc is the HTTP handler for the `/config` page. It outputs the configuration marshaled in YAML format.
func ConfigHandlerFunc(metricsPath string, exporter sql_exporter.Exporter) func(http.ResponseWriter, *http.Request) {
return func(w http.ResponseWriter, r *http.Request) {
config, err := exporter.Config().YAML()
if err != nil {
HandleError(err, metricsPath, w, r)
return
}
configTemplate.Execute(w, &tdata{
MetricsPath: metricsPath,
DocsUrl: docsUrl,
Config: string(config),
})
}
}
// HandleError is an error handler that other handlers defer to in case of error. It is important to not have written
// anything to w before calling HandleError(), or the 500 status code won't be set (and the content might be mixed up).
func HandleError(err error, metricsPath string, w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusInternalServerError)
errorTemplate.Execute(w, &tdata{
MetricsPath: metricsPath,
DocsUrl: docsUrl,
Err: err,
})
}