How to do deep sets and gets in Go's map[string]interface{}?

If I have some arbitrary JSON how can I do deep sets and gets on the nested properties using a slice of map keys and/or slice indexes?

For example, in the following excerpt from the JSON API example:

{
    "data": [{
        "type": "posts",
        "id": "1",
        "title": "JSON API paints my bikeshed!",
        "links": {
            "self": "http://example.com/posts/1",
            "author": {
                "self": "http://example.com/posts/1/links/author",
                "related": "http://example.com/posts/1/author",
                "linkage": { "type": "people", "id": "9" }
            }
        }
    }]
}

I'd like to get the string "9" located at data.0.links.author.linkage.id using something like:

[]interface{}{"data",0,"links","author","linkage","id"}

I know the ideal way to do this is to create nested structs that map to the JSON object which I do for production code, but sometimes I need to do some quick testing which would be nice to do in Go as well.

You have stretchr/objx that provide a similar approach.

Example use:

document, _ := objx.FromJSON(json)
document.Get("path.to.field[0].you.want").Str()

However, unless you really don't know at all the structure of your JSON input ahead of time, this isn't the preferred way to go in golang…