viper作為配置框架，其功能非常的強(qiáng)大，我們沒(méi)有理由不去了解一下。我們先看官網(wǎng)對(duì)它的功能簡(jiǎn)介：
viper是完整配置解決方案，他可以處理所有類(lèi)型和格式的配置文件，他有如下功能：
- 設(shè)置默認(rèn)配置
- 支持讀取 JSON TOML YAML HCL 和 Java 屬性配置文件
- 監(jiān)聽(tīng)配置文件變化，實(shí)時(shí)讀取讀取配置文件內(nèi)容
- 讀取環(huán)境變量值
- 讀取遠(yuǎn)程配置系統(tǒng) (etcd Consul) 和監(jiān)控配置變化
- 讀取命令 Flag 值
- 讀取 buffer 值
- 讀取確切值
乍一看，未免有相見(jiàn)恨晚之感，可仔細(xì)一想，不免腦袋里有另外一種聲音：不會(huì)不支持讀取 zookeeper 吧？好吧，至少我是這樣的。
基于這種想法，當(dāng)然要去立馬嘗試，如下：
|
1
|
viper.AddRemoteProvider("zookeeper", "xx.xx.xx.xx:2181", "/viper/test") |
返回結(jié)果是：
Unsupported Remote Provider Type zookeeper
果不其然，于是追蹤 viper.AddRemoteProvider 的源碼，發(fā)現(xiàn)viper只支持如下幾種
|
1
|
var SupportedRemoteProviders = []string{"etcd", "consul", "firestore"} |
如果就此打住，未免有點(diǎn)太可惜，作為偏執(zhí)狂，總想著能否來(lái)改造下viper，讓其支持 zookeeper ，于是在issue上找是否有人遇到同樣的問(wèn)題，還整讓我找到了， 傳送 。但是不完整，且稍微有點(diǎn)bug。所以根據(jù)他的基礎(chǔ)上，我做了些調(diào)整。進(jìn)入正題，我們開(kāi)始修改viper源碼。說(shuō)明下，我的viper版本是最新的 1.7.0
修改源碼
1、添加zookeeper.go
添加的位置： github.com/bketelsen/crypt/zookeeper , zookeeper 目錄需要自己創(chuàng)建， github.com/bketelsen/crypt 是viper的依賴(lài)包，會(huì)自動(dòng)下載
文件內(nèi)容：
|
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
|
package zookeeperimport ( "errors" "fmt" zk "github.com/samuel/go-zookeeper/zk" //"github.com/xordataexchange/crypt/backend" "github.com/bketelsen/crypt/backend" "strings" "time")type Client struct { client *zk.Conn waitIndex uint64}func New(machines []string) (*Client, error) { zkclient, _, err := zk.Connect(machines, time.Second) if err != nil { return nil, err } return &Client{zkclient, 0}, nil}func (c *Client) Get(key string) ([]byte, error) { resp, _, err := c.client.Get(key) if err != nil { return nil, err } return []byte(resp), nil}func nodeWalk(prefix string, c *Client, vars map[string]string) error { l, stat, err := c.client.Children(prefix) if err != nil { return err } if stat.NumChildren == 0 { b, _, err := c.client.Get(prefix) if err != nil { return err } vars[prefix] = string(b) } else { for _, key := range l { s := prefix + "/" + key _, stat, err := c.client.Exists(s) if err != nil { return err } if stat.NumChildren == 0 { b, _, err := c.client.Get(s) if err != nil { return err } vars[s] = string(b) } else { nodeWalk(s, c, vars) } } } return nil}func (c *Client) GetValues(key string, keys []string) (map[string]string, error) { vars := make(map[string]string) for _, v := range keys { v = fmt.Sprintf("%s/%s", key, v) v = strings.Replace(v, "/*", "", -1) _, _, err := c.client.Exists(v) if err != nil { return vars, err } if v == "/" { v = "" } err = nodeWalk(v, c, vars) if err != nil { return vars, err } } return vars, nil}func (c *Client) List(key string) (backend.KVPairs, error) { var list backend.KVPairs resp, stat, err := c.client.Children(key) if err != nil { return nil, err } if stat.NumChildren == 0 { return list, nil } entries, err := c.GetValues(key, resp) if err != nil { return nil, err } for k, v := range entries { list = append(list, &backend.KVPair{Key: k, Value: []byte(v)}) } return list, nil}func (c *Client) createParents(key string) error { flags := int32(0) acl := zk.WorldACL(zk.PermAll) if key[0] != '/' { return errors.New("Invalid path") } payload := []byte("") pathString := "" pathNodes := strings.Split(key, "/") for i := 1; i < len(pathNodes); i++ { pathString += "/" + pathNodes[i] _, err := c.client.Create(pathString, payload, flags, acl) // not being able to create the node because it exists or not having // sufficient rights is not an issue. It is ok for the node to already // exist and/or us to only have read rights if err != nil && err != zk.ErrNodeExists && err != zk.ErrNoAuth { return err } } return nil}func (c *Client) Set(key string, value []byte) error { err := c.createParents(key) if err != nil { return err } _, err = c.client.Set(key, []byte(value), -1) return err}func (c *Client) Watch(key string, stop chan bool) <-chan *backend.Response { respChan := make(chan *backend.Response, 0) go func() { for { resp, _, watch, err := c.client.GetW(key) if err != nil { respChan <- &backend.Response{nil, err} time.Sleep(time.Second * 5) } select { case e := <-watch: if e.Type == zk.EventNodeDataChanged { resp, _, err = c.client.Get(key) if err != nil { respChan <- &backend.Response{nil, err} } c.waitIndex = 0 respChan <- &backend.Response{[]byte(resp), nil} } } } }() return respChan} |
這個(gè)文件是實(shí)現(xiàn) ConfigManager 接口，我們?cè)谏蠄D中看到 etcd ， consul ， filestore ，均有實(shí)現(xiàn)該接口，接口的定義很簡(jiǎn)單
|
1
2
3
4
5
6
|
type ConfigManager interface { Get(key string) ([]byte, error) List(key string) (KVPairs, error) Set(key string, value []byte) error Watch(key string, stop chan bool) <-chan *Response} |
2、修改config.go
文件的位置： github.com/bketelsen/crypt/config/config.go ，如下圖
在 func NewStandardEtcdConfigManager(machines []string) (ConfigManager, error) 方法下面添加如下方法：
|
1
2
3
4
5
6
7
8
9
|
// NewStandardZookeeperConfigManager returns a new ConfigManager backed by Zookeeper.// Data will be encrypted.func NewStandardZookeeperConfigManager(machines []string) (ConfigManager, error) { store, err := zookeeper.New(machines) if err != nil { return nil, err } return NewStandardConfigManager(store)} |
在 func NewEtcdConfigManager(machines []string, keystore io.Reader) (ConfigManager, error) 方法下面添加如下方法：
|
1
2
3
4
5
6
7
8
9
|
// NewZookeeperConfigManager returns a new ConfigManager backed by zookeeper.// Data will be encrypted.func NewZookeeperConfigManager(machines []string, keystore io.Reader) (ConfigManager, error) { store, err := zookeeper.New(machines) if err != nil { return nil, err } return NewConfigManager(store, keystore)} |
這兩個(gè)方法是初始化 ConfigManager 對(duì)象，也就是我們剛才添加的 zookeeper.go 文件的對(duì)象
3、修改remote.go
文件的位置： github.com/spf13/viper/remote/remote.go ,如下圖
找到74行，用下面的代碼替換 func getConfigManager(rp viper.RemoteProvider) (crypt.ConfigManager, error) 方法
|
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
|
func getConfigManager(rp viper.RemoteProvider) (crypt.ConfigManager, error) { var cm crypt.ConfigManager var err error if rp.SecretKeyring() != "" { var kr *os.File kr, err = os.Open(rp.SecretKeyring()) if err != nil { return nil, err } defer kr.Close() switch rp.Provider() { case "etcd": cm, err = crypt.NewEtcdConfigManager([]string{rp.Endpoint()}, kr) case "zookeeper": cm, err = crypt.NewZookeeperConfigManager([]string{rp.Endpoint()}, kr) case "firestore": cm, err = crypt.NewFirestoreConfigManager([]string{rp.Endpoint()}, kr) default: cm, err = crypt.NewConsulConfigManager([]string{rp.Endpoint()}, kr) } } else { switch rp.Provider() { case "etcd": cm, err = crypt.NewStandardEtcdConfigManager([]string{rp.Endpoint()}) case "zookeeper": cm, err = crypt.NewStandardZookeeperConfigManager([]string{rp.Endpoint()}) case "firestore": cm, err = crypt.NewStandardFirestoreConfigManager([]string{rp.Endpoint()}) default: cm, err = crypt.NewStandardConsulConfigManager([]string{rp.Endpoint()}) } } if err != nil { return nil, err } return cm, nil} |
細(xì)心的讀者可能已經(jīng)發(fā)現(xiàn)，其實(shí)就添加了兩個(gè)case選項(xiàng)：
4、修改viper.go
文件的位置： github.com/spf13/viper/viper.go ,如下圖
取+監(jiān)聽(tīng)zookeeper(1)\image-20200521222843002.png)
找到兩個(gè) SupportedRemoteProviders 定義的定法，1.7.0版本的行號(hào)分別是：290，331。只要添加 zookeeper ,即可
|
1
|
SupportedRemoteProviders = []string{"etcd", "consul", "firestore", "zookeeper"} |
好了，修改代碼的工作已經(jīng)完了，接下來(lái)我們來(lái)測(cè)試：
測(cè)試
注意：zookeeper中已經(jīng)設(shè)置了內(nèi)容
set /viper/test {"appName":"test","nodes":["127.0.0.1","127.0.0.2","127.0.0.3"]}
|
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
|
package mainimport ( "fmt" "github.com/fsnotify/fsnotify" "github.com/spf13/viper" _ "github.com/spf13/viper/remote" "time")type config struct { AppName string Nodes []string}func main() { var waitGroup=sync.WaitGroup{} waitGroup.Add(1) readRemoteZookeeper() go watchRemoteZookeeper() waitGroup.Wait()}func readRemoteZookeeper() { viper.AddRemoteProvider("zookeeper", "62.234.15.24:2181", "/viper/test") viper.SetConfigType("json") err := viper.ReadRemoteConfig() if err != nil { panic(fmt.Sprintf("read remote zookeeper error:+%v", err)) } var C config viper.Unmarshal(&C) fmt.Printf("從zookeeper讀取配置內(nèi)容:%+v\n", C)}func watchRemoteZookeeper() { go func() { for { //delay after each request time.Sleep(time.Second * 5) err := viper.WatchRemoteConfig() if err != nil { fmt.Errorf("unable to read remote config: %v", err) continue } fmt.Printf("從zookeeper讀取更新內(nèi)容:appName=%s,nodes=%+v\n", viper.Get("appName"), viper.Get("nodes")) } }()} |
輸出內(nèi)容：
從zookeeper讀取配置內(nèi)容:{AppName:test Nodes:[127.0.0.1 127.0.0.2 127.0.0.3]}
從zookeeper讀取更新內(nèi)容:appName=test,nodes=[127.0.0.1 127.0.0.2 127.0.0.3]
如果我們修改zookeeper的內(nèi)容，則viper會(huì)讀取到更新后的內(nèi)容：
|
1
|
set /viper/test {"appName":"test","nodes":["127.0.0.1","127.0.0.2","127.0.0.3","127.0.0.4"]} |
|
1
|
從zookeeper讀取更新內(nèi)容:appName=test,nodes=[127.0.0.1 127.0.0.2 127.0.0.3 127.0.0.4] |
結(jié)語(yǔ)
讓viper支持 zookeeper 并不復(fù)雜的，并且基本上不需要修改原有的方法， 這要?dú)w結(jié)于viper用到一個(gè)非常重要的設(shè)計(jì)原則： 開(kāi)閉原則 ，讀者可以自行體會(huì)。
關(guān)于viper的基本使用， github 已經(jīng)有非常詳細(xì)的例子，這里就不再贅述，如有疑問(wèn)，可以私信我
到此這篇關(guān)于viper配置框架的介紹支持zookeeper的讀取和監(jiān)聽(tīng)的文章就介紹到這了,更多相關(guān)viper配置框架支持zookeeper的讀取和監(jiān)聽(tīng)內(nèi)容請(qǐng)搜索服務(wù)器之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持服務(wù)器之家！
原文鏈接：https://studygolang.com/articles/28829
