example/plugins/lua-api/connect_geoip.lua

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-- This example depends on "luajit-geoip".
-- It illustrates how to connect to GeoIP and use it to look up country of an IP address.
-- It can be used in plugin.config with the lua plugin.

-- Setup Instructions
-- 1) install GeoIP - 1.6.12
-- 2) install GeoIP legacy country database - https://dev.maxmind.com/geoip/legacy/install/country/
-- 3) install luajit-geoip (https://github.com/leafo/luajit-geoip)
--    or just copy geoip/init.lua from the repo to /usr/local/share/lua/5.1/geoip/init.lua
-- 4) You may need to make change so luajit-geoip does ffi.load() on /usr/local/lib/libGeoIP.so

ts.add_package_path('/usr/local/share/lua/5.1/?.lua')

local geoip = require 'geoip'

function do_global_send_response()
  local res = geoip.lookup_addr("8.8.8.8")
  ts.client_response.header['X-Country'] = res.country_code
end