gluon/package/gluon-authorized-keys/luasrc/lib/gluon/upgrade/100-authorized-keys

#!/usr/bin/lua

local site = require 'gluon.site'
local file = '/etc/dropbear/authorized_keys'

local keys = {}

function load_keys()
  for line in io.lines(file) do
    keys[line] = true
  end
end

pcall(load_keys)

local f = io.open(file, 'a')
for _, key in ipairs(site.authorized_keys()) do
  if not keys[key] then
    f:write(key .. '\n')
  end
end
f:close()