Go語言之讀取yaml設定檔，轉換成struct結構，json形式輸出

標籤：go   yaml   

1、例子11.1、yaml檔案內容如下:

host: localhost:3306user: rootpwd: 123456dbname: test  

1.2、代碼如下：

//將yaml檔案，轉換成對象，再轉換成json格式輸出package mainimport (    "encoding/json"    "fmt"    "gopkg.in/yaml.v2"    "io/ioutil")//定義conf類型//類型裡的屬性，全是設定檔裡的屬性type conf struct {    Host   string `yaml: "host"`    User   string `yaml:"user"`    Pwd    string `yaml:"pwd"`    Dbname string `yaml:"dbname"`}func main() {    var c conf    //讀取yaml設定檔    conf := c.getConf()    fmt.Println(conf)    //將對象，轉換成json格式    data, err := json.Marshal(conf)    if err != nil {        fmt.Println("err:\t", err.Error())        return    }    //最終以json格式，輸出    fmt.Println("data:\t", string(data))}//讀取Yaml設定檔,//並轉換成conf對象func (c *conf) getConf() *conf {    //應該是 絕對位址    yamlFile, err := ioutil.ReadFile("E:\\Program\\go2\\goPath\\src\\xingej-go\\xingej-go\\xingej-go666\\lib\\yaml\\conf.yaml")    if err != nil {        fmt.Println(err.Error())    }    err = yaml.Unmarshal(yamlFile, c)    if err != nil {        fmt.Println(err.Error())    }    return c}

如果某一個包，本地沒有的話，可以在cmd中使用下面的命令，進行下載，如:
go get gopkg.in/yaml.v2

==基本格式:== go get 包的路徑

2、例子2，該設定檔中，存在map,slice類型，稍微複雜些2.1、 設定檔內容：

apiVersion: v1kind: KafkaCluster2metadata:  name: kafka-operator  labels:    config1:      address: kafka-operator-labels-01      id: kafka-operator-labels-02      name: mysql-example-cluster-master      nodeName: 172.16.91.21      role: master    config2:       address: kafka-operator-labels-01       id: kafka-operator-labels-02       name: mysql-example-cluster-slave       nodeName: 172.16.91.110       role: slavespec:  replicas: 1  name: kafka-controller  image: 172.16.26.4:5000/nginx  ports: 8088  conditions:    - containerPort: 8080      requests:        cpu: "0.25"        memory: "512Mi"      limits:        cpu: "0.25"        memory: "1Gi"    - containerPort: 9090      requests:        cpu: "0.33"        memory: "333Mi"      limits:        cpu: "0.55"        memory: "5Gi"

2.2、 代碼如下：

package mainimport (    "encoding/json"    "fmt"    "gopkg.in/yaml.v2"    "io/ioutil")type KafkaCluster struct {    ApiVersion string   `yaml:"apiVersion"`    Kind       string   `yaml: "kind"`    Metadata   Metadata `yaml: "metadata"`    Spec       Spec     `yaml: "spec"`}type Metadata struct {    Name string `yaml:"name"`    //map類型    Labels map[string]*NodeServer `yaml:"labels"`}type NodeServer struct {    Address string `yaml: "address"`    Id      string `yaml: "id"`    Name    string `yaml: "name"`    //注意，屬性裡，如果有大寫的話，tag裡不能存在空格    //如yaml: "nodeName" 格式是錯誤的，中間多了一個空格，不能識別的    NodeName string `yaml:"nodeName"`    Role     string `yaml: "role"`}type Spec struct {    Replicas int    `yaml: "replicas"`    Name     string `yaml: "name"`    Image    string `yaml: "iamge"`    Ports    int    `yaml: "ports"`    //slice類型    Conditions []Conditions `yaml: "conditions"`}type Conditions struct {    ContainerPort string   `yaml:"containerPort"`    Requests      Requests `yaml: "requests"`    Limits        Limits   `yaml: "limits"`}type Requests struct {    CPU    string `yaml: "cpu"`    MEMORY string `yaml: "memory"`}type Limits struct {    CPU    string `yaml: "cpu"`    MEMORY string `yaml: "memory"`}func main() {    var c KafkaCluster    //讀取yaml設定檔, 將yaml設定檔，轉換struct類型    conf := c.getConf()    //將對象，轉換成json格式    data, err := json.Marshal(conf)    if err != nil {        fmt.Println("err:\t", err.Error())        return    }    //最終以json格式，輸出    fmt.Println("data:\t", string(data))}//讀取Yaml設定檔,//並轉換成conf對象  struct結構func (kafkaCluster *KafkaCluster) getConf() *KafkaCluster {    //應該是 絕對位址    yamlFile, err := ioutil.ReadFile("E:\\Program\\go2\\goPath\\src\\xingej-go\\xingej-go\\xingej-go666\\lib\\yaml\\sparkConfig.yaml")    if err != nil {        fmt.Println(err.Error())    }    //err = yaml.Unmarshal(yamlFile, kafkaCluster)    err = yaml.UnmarshalStrict(yamlFile, kafkaCluster)    if err != nil {        fmt.Println(err.Error())    }    return kafkaCluster}

2.3、運行結果：

data:    {"ApiVersion":"v1","Kind":"KafkaCluster2","Metadata":{"Name":"kafka-operator","Labels":{"config1":{"Address":"kafka-operator-labels-01","Id":"kafka-operator-labels-02","Name":"mysql-example-cluster-master","NodeName":"172.16.91.21","Role":"master"},"config2":{"Address":"kafka-operator-labels-01","Id":"kafka-operator-labels-02","Name":"mysql-example-cluster-slave","NodeName":"172.16.91.110","Role":"slave"}}},"Spec":{"Replicas":1,"Name":"kafka-controller","Image":"172.16.26.4:5000/nginx","Ports":8088,"Conditions":[{"ContainerPort":"8080","Requests":{"CPU":"0.25","MEMORY":"512Mi"},"Limits":{"CPU":"0.25","MEMORY":"1Gi"}},{"ContainerPort":"9090","Requests":{"CPU":"0.33","MEMORY":"333Mi"},"Limits":{"CPU":"0.55","MEMORY":"5Gi"}}]}}

==注意：==

yaml設定檔裡，如果屬性裡存在大寫的話，定義對應的屬性時，一定不能有空格，可以參考上面例子中NodeServer裡的說明  

3 例子3，讀取yaml設定檔中的某一個屬性3.1、 設定檔的內容：

apiVersion: v1Kind: KafkaCluster

3.2、代碼如下：

//測試讀取yaml檔案的package mainimport (    "fmt"    "github.com/kylelemons/go-gypsy/yaml")func main() {    file, err := yaml.ReadFile("E:\\Program\\go2\\goPath\\src\\xingej-go\\xingej-go\\xingej-go666\\lib\\yaml\\nginx")    if err != nil {        panic(err.Error())    }    apiVersion, error := file.Get("apiVersion")    if error != nil {        panic(error.Error())    }    fmt.Println("=apiVersion===:\t", apiVersion)}

3.3、運行結果 ：

=apiVersion===:  v1 

4. 說明

例子3中用到的yaml解析包跟前面兩個例子不是同一個。  "gopkg.in/yaml.v2""github.com/kylelemons/go-gypsy/yaml"  例子1，例子2 是整體讀取Yaml設定檔，轉換成其他格式  例子3，是讀取yaml配置裡的某一個屬性，  因此，兩者的使用情境是不一樣的

Go語言之讀取yaml設定檔，轉換成struct結構，json形式輸出