/
base.go
218 lines (181 loc) · 5.26 KB
/
base.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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
// Package writers provides objects that can send colected resource data to external place.
package writers
import (
"bytes"
"encoding/json"
"errors"
"reflect"
"github.com/Sirupsen/logrus"
"github.com/go-fsnotify/fsnotify"
resourced_config "github.com/resourced/resourced/config"
"github.com/resourced/resourced/libprocess"
"github.com/resourced/resourced/libstring"
)
var writerConstructors = make(map[string]func() IWriter)
// Register makes any writer constructor available by name.
func Register(name string, constructor func() IWriter) {
if constructor == nil {
panic("writer: Register writer constructor is nil")
}
if _, dup := writerConstructors[name]; dup {
panic("writer: Register called twice for writer constructor " + name)
}
writerConstructors[name] = constructor
}
// NewGoStruct instantiates IWriter
func NewGoStruct(name string) (IWriter, error) {
constructor, ok := writerConstructors[name]
if !ok {
return nil, errors.New("GoStruct is undefined.")
}
return constructor(), nil
}
// NewGoStructByConfig instantiates IWriter given Config struct
func NewGoStructByConfig(config resourced_config.Config) (IWriter, error) {
writer, err := NewGoStruct(config.GoStruct)
if err != nil {
return nil, err
}
// Populate IWriter fields dynamically
if len(config.GoStructFields) > 0 {
for structFieldInString, value := range config.GoStructFields {
goStructField := reflect.ValueOf(writer).Elem().FieldByName(structFieldInString)
if goStructField.IsValid() && goStructField.CanSet() {
valueOfValue := reflect.ValueOf(value)
goStructField.Set(valueOfValue)
}
}
}
return writer, err
}
// IWriter is general interface for writer.
type IWriter interface {
WatchDir(string, func() error) error
Run() error
SetConfigs(*resourced_config.Configs)
SetReadersDataInBytes(map[string][]byte)
SetReadersData(map[string]interface{})
GetReadersData() map[string]interface{}
SetData(interface{})
GetData() interface{}
GetJsonProcessor() string
GenerateData() error
ToJson() ([]byte, error)
}
type Base struct {
Configs *resourced_config.Configs
ReadersData map[string]interface{}
Data interface{}
JsonProcessor string
}
// WatchDir watches a directory and execute callback on any changes.
func (b *Base) WatchDir(path string, callback func() error) error {
watcher, err := fsnotify.NewWatcher()
if err != nil {
return err
}
defer watcher.Close()
err = watcher.Add(path)
if err != nil {
return err
}
for {
select {
case event := <-watcher.Events:
if (event.Op&fsnotify.Create == fsnotify.Create) || (event.Op&fsnotify.Remove == fsnotify.Remove) || (event.Op&fsnotify.Write == fsnotify.Write) || (event.Op&fsnotify.Rename == fsnotify.Rename) {
logrus.WithFields(logrus.Fields{
"Path": path,
"Event": event.String(),
}).Info("Changes happened, executing callback")
callback()
}
case err := <-watcher.Errors:
if err != nil {
logrus.WithFields(logrus.Fields{
"Error": err.Error(),
"Path": path,
}).Error("Error while watching path")
}
}
}
return nil
}
// Run executes the writer.
func (b *Base) Run() error {
return nil
}
// SetConfigs remembers configs data in-memory.
func (b *Base) SetConfigs(configs *resourced_config.Configs) {
b.Configs = configs
}
// SetReadersDataInBytes pulls readers data and store them on ReadersData field.
func (b *Base) SetReadersDataInBytes(readersJsonBytes map[string][]byte) {
if b.ReadersData == nil {
b.ReadersData = make(map[string]interface{})
}
for key, jsonBytes := range readersJsonBytes {
var data interface{}
err := json.Unmarshal(jsonBytes, &data)
if err == nil {
b.ReadersData[key] = data
}
}
}
// SetReadersData assigns ReadersData field.
func (b *Base) SetReadersData(readersData map[string]interface{}) {
b.ReadersData = readersData
}
// GetReadersData returns ReadersData field.
func (b *Base) GetReadersData() map[string]interface{} {
return b.ReadersData
}
// SetData assigns Data field.
func (b *Base) SetData(data interface{}) {
b.Data = data
}
// GetData returns Data field.
func (b *Base) GetData() interface{} {
return b.Data
}
// GetJsonProcessor returns json processor path.
func (b *Base) GetJsonProcessor() string {
path := ""
if b.JsonProcessor != "" {
path = libstring.ExpandTildeAndEnv(b.JsonProcessor)
}
return path
}
// GenerateData pulls ReadersData field and set it to Data field.
// If JsonProcessor is defined, use it to mangle JSON and save the new JSON on Data field.
func (b *Base) GenerateData() error {
var err error
processorPath := b.GetJsonProcessor()
if processorPath == "" {
// If there's no JsonProcessor
b.SetData(b.GetReadersData())
} else {
// If there is a JsonProcessor
cmd := libprocess.NewCmd(processorPath)
readersData := b.GetReadersData()
readersDataJsonBytes, err := json.Marshal(readersData)
if err != nil {
return err
}
cmd.Stdin = bytes.NewReader(readersDataJsonBytes)
postProcessingDataBytes, err := cmd.Output()
if err != nil {
return err
}
var postProcessingData interface{}
err = json.Unmarshal(postProcessingDataBytes, &postProcessingData)
if err != nil {
return err
}
b.SetData(postProcessingData)
}
return err
}
// ToJson serialize Data field to JSON.
func (b *Base) ToJson() ([]byte, error) {
return json.Marshal(b.Data)
}