Kong Custom Plugin Admin Interface extension : need access to config of plugin

Question

I'm building a custom plugin and I'm extending the admin interface via api.lua

Functions have the 'self' property where i can get request information but I also need access to the plugin configuration (like handler.lua) .

How can I do that ?

Kong 2.7.0.

return {
    ["/my-route/:id"] = {
        GET = function(self)
        -- do some stuff
        end
    }    
}

Thx,

Peter

Update

schema.lua

return {
    no_consumer = true, -- this plugin will only be API-wide
    fields = {
        redis_host = { type = "string" },
        redis_port = { type = "number", default = 6379 },
        redis_password = { type = "string" },
        redis_timeout = { type = "number", default = 2000 },
        redis_database = { type = "number", default = 1 }
    }
}