aboutsummaryrefslogtreecommitdiff
path: root/cmd/monfront/server.go
blob: 8e53c648d5d51eda5d15833bcfc3149a4cdf749d (plain) (blame)
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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
package main

import (
	"compress/gzip"
	"database/sql"
	"encoding/json"
	"fmt"
	"html/template"
	"io"
	"log"
	"net"
	"net/http"
	"strings"
	"time"
)

type (
	server struct {
		listen net.Listener
		db     *sql.DB
		h      *http.ServeMux
		tmpl   *template.Template
		auth   func(c *Context) error // authentication
		autho  func(c *Context) error // authorization
	}

	handleFunc func(c *Context)

	Context struct {
		// internal maintenance stuff
		w    http.ResponseWriter
		r    *http.Request
		tmpl *template.Template
		db   *sql.DB

		User    string  `json:"-"`
		Filter  *filter `json:"-"`
		CanEdit bool    `json:"-"` // has user permission to edit stuff?

		Title        string                   `json:"title,omitempty"`
		CurrentPath  string                   `json:"-"`
		Error        string                   `json:"error,omitempty"`
		Mappings     map[int]map[int]MapEntry `json:"mappings,omitempty"`
		Commands     map[string]int           `json:"commands,omitempty"`
		Checks       []check                  `json:"checks,omitempty"`
		CheckDetails *checkDetails            `json:"check_details,omitempty"`
		Groups       []group                  `json:"groups,omitempty"`
		Unhandled    bool                     `json:"-"` // set this flag when unhandled was called

		Content map[string]any `json:"-"` // used for the configuration dashboard
	}
)

func newServer(l net.Listener, db *sql.DB, tmpl *template.Template, auth func(c *Context) error, autho func(c *Context) error) *server {
	s := &server{
		listen: l,
		db:     db,
		tmpl:   tmpl,
		h:      http.NewServeMux(),
		auth:   auth,
		autho:  autho,
	}
	return s
}

func (s *server) ListenAndServe() error {
	server := http.Server{Handler: s.h}
	return server.Serve(s.listen)
}

func (s *server) Handle(path string, fun handleFunc) {
	s.h.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
		c := &Context{
			w:    w,
			r:    r,
			tmpl: s.tmpl,
			db:   s.db,
		}
		if err := s.auth(c); err != nil {
			return
		}
		if err := s.autho(c); err != nil {
			return
		}
		fun(c)
		return
	})
}

func (s *server) HandleStatic(path string, h func(w http.ResponseWriter, r *http.Request)) {
	s.h.HandleFunc(path, h)
}

// Render calls the template with the given name to
// render the appropiate content.
// In case of an error, a error message is automatically pushed
// to the client.
func (c *Context) Render(t string) error {
	var w io.Writer = c.w
	if strings.Contains(c.r.Header.Get("Accept-Encoding"), "gzip") {
		gz, err := gzip.NewWriterLevel(w, 5)
		if err != nil {
			log.Printf("could not create gzip writer: %s", err)
			return fmt.Errorf("could not create gzip writer: %s", err)
		}
		defer gz.Close()
		w = gz
		c.w.Header().Set("Content-Encoding", "gzip")
	}

	if c.r.Header.Get("Accept") == "application/json" {
		c.w.Header().Set("Content-Type", "application/json")
		enc := json.NewEncoder(w)
		enc.SetIndent("", "") // disable indentation to save traffic
		if err := enc.Encode(c); err != nil {
			c.w.WriteHeader(http.StatusInternalServerError)
			c.w.Write([]byte("could not write json output"))
			log.Printf("could not write json output: %s", err)
			return err
		}
		return nil
	}

	if err := c.tmpl.ExecuteTemplate(w, t, c); err != nil {
		c.w.WriteHeader(http.StatusInternalServerError)
		c.w.Write([]byte("problem with a template"))
		log.Printf("could not execute template: %s", err)
		return err
	}
	return nil
}

// Get a cookie value.
func (c *Context) GetCookieVal(name string) string {
	cook, err := c.r.Cookie(name)
	if err == http.ErrNoCookie {
		return ""
	}
	return cook.Value
}

// Set a new key value cookie with a deadline.
func (c *Context) SetCookie(name, val string, expire time.Time) {
	cook := http.Cookie{
		Name:     name,
		Value:    val,
		Expires:  expire,
		Secure:   true,
		SameSite: http.SameSiteStrictMode,
		HttpOnly: true,
		Path:     "/",
	}
	http.SetCookie(c.w, &cook)
	return
}