How to parse the json array of the format below - arrays

Question

{
"machines": [{
"name": "relay_1",
"totalmem": "3G",
"machinemem": "6G"
}, {
"name": "relay_2",
"totalmem": "30G",
"machinemem": "4G"
}]
}
tried doing the parsing using the below code
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("relay called")
conf, _ = rootCmd.Flags().GetString("conf")
if conf != "" {
fmt.Println("From Create Command : ", conf)
}
data, err := ioutil.ReadFile("file.txt") // data has type []byte
if err != nil {
log.Fatal(err)
}
var result []map[string]interface{}
json.Unmarshal(data, &result)
relays := result["relays"].(map[string]interface{})
for key, relay := range relays {
fmt.Println("name :", relay["name"],
"totalmem:", relay["totalmem"],
"relaymem:", relay["relaymem"])
}
},
But I am getting the error as below which indicates that the type is invalid
cmd/create_relay.go:54:29: invalid type assertion: result["relays"].(map[string]) (non-interface type map[string]interface {} on left)
Can someone let me know how to parse the json below by using the interfaces as below

Answer 1

It worked with the below code.
type Relays struct {
Relays []Relay `json:"relays"`
}
type Relay struct {
Name string `json:"name"`
Totalmem string `json:"totalmem"`
Relaymem string `json:"relaymem"`
}
// relayCmd represents the relay command
var createrelayCmd = &cobra.Command{
Use: "relay",
Short: "A brief description of your command",
Long: `A longer description that spans multiple lines and likely contains examples
and usage of using your command. For example:
Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.`,
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("relay called")
conf, _ = rootCmd.Flags().GetString("conf")
if conf != "" {
fmt.Println("From Create Command : ", conf)
jsonFile, err := os.Open(conf)
// if we os.Open returns an error then handle it
if err != nil {
fmt.Println(err)
}
fmt.Println("Successfully Opened users.json")
// defer the closing of our jsonFile so that we can parse it later on
defer jsonFile.Close()
data, err := ioutil.ReadAll(jsonFile) // data has type []byte
if err != nil {
log.Fatal(err)
}
var relays Relays
json.Unmarshal(data,&relays)
for i := 0; i < len(relays.Relays); i++ {
fmt.Println("User Name: " + relays.Relays[i].Name)
fmt.Println("User Totalmem: " + relays.Relays[i].Totalmem)
fmt.Println("User Relaymem: " + relays.Relays[i].Relaymem)
}
}
},
}

Answer 2

result in your code is an array of map and you are using result["relays"] which is invalid.
Your code should be something like this:
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("relay called")
conf, _ = rootCmd.Flags().GetString("conf")
if conf != "" {
fmt.Println("From Create Command : ", conf)
}
data, err := ioutil.ReadFile("file.txt") // data has type []byte
if err != nil {
log.Fatal(err)
}
var result map[string]interface{}
json.Unmarshal(data, &result)
relays := result["relays"].([]interface{})
for _, relay := range relays {
relayM := relay.(map[string]interface{})
fmt.Println("name :", relayM["name"].(string),
"totalmem:", relayM["totalmem"].(string),
"relaymem:", relayM["relaymem"].(string))
}
},