Golang Json marshalling - json

Question

type Status struct {
slug string `json:"slug"`
}
type Instance struct {
Slug string `json:"slug"`
Stat map[string]*Status `json:"status"`
}
This Json response is recieved for API call:
[ {
"status": {
"stop": false,
"traffic": true,
"label": null,
"dead": true,
"slug": "up",
},
"slug": "instances_raw",
"started_at": "15120736198",
"replacement": null
},
{
"status": {
"stop": false,
"traffic": true,
"label": null,
"dead": true,
"slug": "down",
},
"slug": "instance_raw2",
"started_at": "1512073194",
"replacement": null
}
]
I am trying to marshall json into above struct but running into issue:
instances := make([]Instance, 0)
res := api call return above json
body, _ := ioutil.ReadAll(res.Body)
json.Unmarshal(body, &instances)
fmt.Println("I am struct %s",instances)
It is marshalling into:
I am struct %s [{ map[stop:0xc42018e1b0 dead:0xc42018e1e0 label:<nil> running:0xc42018e220 down:0xc42018e150 traffic:0xc42018e180]}]
Can someone help me figure out why it is not marshalling as I am expecting?
Expected marshalling:
[{instances_raw map[slug:up]} {instances_raw2 map[slug:down]}]

Answer 1

The structs do not match the structure of the data. Perhaps you wanted this:
type Status struct {
Slug string `json:"slug"`
}
type Instance struct {
Slug string `json:"slug"`
Stat Status `json:"status"`
}
Output: [{instances_raw {up}} {instance_raw2 {down}}]
run it on the plaground
or this:
type Instance struct {
Slug string `json:"slug"`
Stat map[string]interface{} `json:"status"`
}
Output: [{instances_raw map[label: dead:true slug:up stop:false traffic:true]} {instance_raw2 map[slug:down stop:false traffic:true label: dead:true]}]
run it on the playground
Always check errors. The example JSON above is not valid and the json.Unmarshal function reports this error.