blob: ff0becfe5d0785641f0b3092619802ae6deef226 [file] [log] [blame]
Girish Gowdra64503432020-01-07 10:59:10 +05301// Copyright (c) 2016 Uber Technologies, Inc.
2//
3// Permission is hereby granted, free of charge, to any person obtaining a copy
4// of this software and associated documentation files (the "Software"), to deal
5// in the Software without restriction, including without limitation the rights
6// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7// copies of the Software, and to permit persons to whom the Software is
8// furnished to do so, subject to the following conditions:
9//
10// The above copyright notice and this permission notice shall be included in
11// all copies or substantial portions of the Software.
12//
13// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19// THE SOFTWARE.
20
21package zap
22
23import (
24 "errors"
25 "fmt"
26 "io"
27 "net/url"
28 "os"
29 "strings"
30 "sync"
31
32 "go.uber.org/zap/zapcore"
33)
34
35const schemeFile = "file"
36
37var (
38 _sinkMutex sync.RWMutex
39 _sinkFactories map[string]func(*url.URL) (Sink, error) // keyed by scheme
40)
41
42func init() {
43 resetSinkRegistry()
44}
45
46func resetSinkRegistry() {
47 _sinkMutex.Lock()
48 defer _sinkMutex.Unlock()
49
50 _sinkFactories = map[string]func(*url.URL) (Sink, error){
51 schemeFile: newFileSink,
52 }
53}
54
55// Sink defines the interface to write to and close logger destinations.
56type Sink interface {
57 zapcore.WriteSyncer
58 io.Closer
59}
60
61type nopCloserSink struct{ zapcore.WriteSyncer }
62
63func (nopCloserSink) Close() error { return nil }
64
65type errSinkNotFound struct {
66 scheme string
67}
68
69func (e *errSinkNotFound) Error() string {
70 return fmt.Sprintf("no sink found for scheme %q", e.scheme)
71}
72
73// RegisterSink registers a user-supplied factory for all sinks with a
74// particular scheme.
75//
76// All schemes must be ASCII, valid under section 3.1 of RFC 3986
77// (https://tools.ietf.org/html/rfc3986#section-3.1), and must not already
78// have a factory registered. Zap automatically registers a factory for the
79// "file" scheme.
80func RegisterSink(scheme string, factory func(*url.URL) (Sink, error)) error {
81 _sinkMutex.Lock()
82 defer _sinkMutex.Unlock()
83
84 if scheme == "" {
85 return errors.New("can't register a sink factory for empty string")
86 }
87 normalized, err := normalizeScheme(scheme)
88 if err != nil {
89 return fmt.Errorf("%q is not a valid scheme: %v", scheme, err)
90 }
91 if _, ok := _sinkFactories[normalized]; ok {
92 return fmt.Errorf("sink factory already registered for scheme %q", normalized)
93 }
94 _sinkFactories[normalized] = factory
95 return nil
96}
97
98func newSink(rawURL string) (Sink, error) {
99 u, err := url.Parse(rawURL)
100 if err != nil {
101 return nil, fmt.Errorf("can't parse %q as a URL: %v", rawURL, err)
102 }
103 if u.Scheme == "" {
104 u.Scheme = schemeFile
105 }
106
107 _sinkMutex.RLock()
108 factory, ok := _sinkFactories[u.Scheme]
109 _sinkMutex.RUnlock()
110 if !ok {
111 return nil, &errSinkNotFound{u.Scheme}
112 }
113 return factory(u)
114}
115
116func newFileSink(u *url.URL) (Sink, error) {
117 if u.User != nil {
118 return nil, fmt.Errorf("user and password not allowed with file URLs: got %v", u)
119 }
120 if u.Fragment != "" {
121 return nil, fmt.Errorf("fragments not allowed with file URLs: got %v", u)
122 }
123 if u.RawQuery != "" {
124 return nil, fmt.Errorf("query parameters not allowed with file URLs: got %v", u)
125 }
126 // Error messages are better if we check hostname and port separately.
127 if u.Port() != "" {
128 return nil, fmt.Errorf("ports not allowed with file URLs: got %v", u)
129 }
130 if hn := u.Hostname(); hn != "" && hn != "localhost" {
131 return nil, fmt.Errorf("file URLs must leave host empty or use localhost: got %v", u)
132 }
133 switch u.Path {
134 case "stdout":
135 return nopCloserSink{os.Stdout}, nil
136 case "stderr":
137 return nopCloserSink{os.Stderr}, nil
138 }
139 return os.OpenFile(u.Path, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
140}
141
142func normalizeScheme(s string) (string, error) {
143 // https://tools.ietf.org/html/rfc3986#section-3.1
144 s = strings.ToLower(s)
145 if first := s[0]; 'a' > first || 'z' < first {
146 return "", errors.New("must start with a letter")
147 }
148 for i := 1; i < len(s); i++ { // iterate over bytes, not runes
149 c := s[i]
150 switch {
151 case 'a' <= c && c <= 'z':
152 continue
153 case '0' <= c && c <= '9':
154 continue
155 case c == '.' || c == '+' || c == '-':
156 continue
157 }
158 return "", fmt.Errorf("may not contain %q", c)
159 }
160 return s, nil
161}