Convert interface{} to map

I am trying to read a json file, the code that does that has something like below

var configurations map[string]interface{}

func GetConfigMap(name string) interface{} {
	valueMap := configurations[name]
	return valueMap.(map[string]interface{})
}

And I am trying to read the map as below,

glossary := jsonreader.GetConfigMap("glossary")
fmt.Println(glossary["GlossDiv"])

The json structure is as below,

{    "glossary": {
        "title": "example glossary",
		"GlossDiv": {
            "title": "S",
			"GlossList": {
                "GlossEntry": {
                    "ID": "SGML",
					"SortAs": "SGML",
					"GlossTerm": "Standard Generalized Markup Language",
					"Acronym": "SGML",
					"Abbrev": "ISO 8879:1986",
					"GlossDef": {
                        "para": "A meta-markup language, used to create markup languages such as DocBook.",
						"GlossSeeAlso": ["GML", "XML"]
                    },
					"GlossSee": "markup"
                }
            }
        }
    }
}

I am getting an exception that says -

invalid operation: glossary["GlossDiv"] (type interface {} does not support indexing)

How do I make this work?

I'm not sure what you're trying to do based on your question, but can't you just change the return type of the function?

func GetConfigMap(name string) map[string]interface{} {
    valueMap := configurations[name]
    return valueMap.(map[string]interface{})
}