Is it possible to have a structure for dynamic keys along with static keys for json in Golang

My apologies for the basic question. I am new to Golang and I have the json to parse as below

{
   "config1":{
      "Parameters":{
         "Pm1":"value",
         "Pm2":"value",
         "Pm3":"value"
      },
      "dynamic_key1":{
         "Parameters":{
            "a":"value",
            "b":"value",
            "c":"value",
            "d":"value"
         },
         "Epoch":"value"
      },
      "Epoch":"value"
   }
}

I am trying to write a struct to parse this json and wrote the struct in the following way.

type Parameters struct {
    Pm1 string `json:"Pm1"`
    Pm2 string `json:"Pm2"`
    Pm3 string `json:"Pm3"`
}

type dynamicParametes struct {
    a string `json:"a"`
    b string `json:"b"`
    c string `json:"c"`
    d string `json:"d"`
}

type dynamic struct {
    Parameters dynamicParametes `json:"Parameters"`
    Epoch      string           `json:"Epoch"`
}

type config1 struct {
    Parameters   Parameters         `json:"Parameters"`
    Dynamic_keys map[string]dynamic `json:"-"`
    Epoch        string             `json:"Epoch"`
}

type config struct {
    config1 config1 `json:"config1"`
}

I was hoping that the map will match all the matching keys with dynamic structs and show them in the map. But, I see it created an empty map in the response.

Solution

Implemented custom unmarshler for config type.

Note

If you don't need Parameters and dynamicParametes as struct types, you can simply unmarshal them into map[string]string
you have to expose all fields in your structs to do json unmarshaling
validate your json string

type config struct {
    Config1 config1 `json:"config1"`
}

type _config config

func (b *config) UnmarshalJSON(data []byte) error {

    var v = struct {
        Config1 map[string]interface{} `json:"config1"`
    }{}
    if err := json.Unmarshal(data, &v); err != nil {
        return err
    }

    c := _config{}
    err := json.Unmarshal(data, &c)
    if err != nil {
        return err
    }
    
    b.Config1.Parameters = c.Config1.Parameters
    b.Config1.Epoch = c.Config1.Epoch

    if b.Config1.Dynamic_keys == nil {
        b.Config1.Dynamic_keys = map[string]dynamic{}
    }

    for key, config := range v.Config1 {
        if key == `Parameters` || key == `Epoch` {
            continue
        }
        data, err := json.Marshal(config)
        if err != nil {
            return err
        }

        d := dynamic{}
        err = json.Unmarshal(data, &d)
        if err != nil {
            return err
        }
        b.Config1.Dynamic_keys[key] = d
    }

    return nil
}

you can see full code here