[cli] use resty.sandbox to load environment configurations

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - 3scale configuration (staging/production) can be passed as `-3` or `--channel` on the CLI [PR #590](https://github.com/3scale/apicast/pull/590)
 - APIcast CLI loads environments defined by `APICAST_ENVIRONMENT` variable [PR #590](https://github.com/3scale/apicast/pull/590)
 - Endpoint in management API to retrieve all the JSON manifests of the policies [PR #592](https://github.com/3scale/apicast/pull/592)
+- More complete global environment when loading environment policies [PR #596](https://github.com/3scale/apicast/pull/596)
 
 ## Fixed
 

gateway/src/apicast/cli/environment.lua

@@ -6,13 +6,12 @@
 local pl_path = require('pl.path')
 local resty_env = require('resty.env')
 local linked_list = require('apicast.linked_list')
+local sandbox = require('resty.sandbox')
 local util = require('apicast.util')
 local setmetatable = setmetatable
 local loadfile = loadfile
-local pcall = pcall
 local require = require
 local assert = assert
-local error = error
 local print = print
 local pairs = pairs
 local ipairs = ipairs
@@ -146,11 +145,15 @@ function _M:add(env)
         return nil, 'no configuration found'
     end
 
-    local config = loadfile(path, 't', {
-        print = print, inspect = require('inspect'), context = self._context, arg = arg, cli = arg,
-        tonumber = tonumber, tostring = tostring, os = { getenv = resty_env.value },
-        pcall = pcall, require = require, assert = assert, error = error,
-    })
+    -- using sandbox is not strictly needed,
+    -- but it is a nice way to add some extra env to the loaded code
+    -- and not using global variables
+    local box = sandbox.new()
+    local config = loadfile(path, 't', setmetatable({
+        inspect = require('inspect'), context = self._context,
+        arg = arg, cli = arg,
+        os = { getenv = resty_env.value },
+    }, { __index = box.env }))
 
     if not config then
         return nil, 'invalid config'

gateway/src/resty/sandbox.lua

@@ -209,14 +209,16 @@ local mt = {
   __call = function(loader, ...) return loader.env.require(...) end
 }
 
+local empty_t = {}
+
 function _M.new(load_paths)
   -- need to create global variable package that mimics the native one
   local package = {
     loaded = {},
     preload = preload,
     searchers = {}, -- http://www.lua.org/manual/5.2/manual.html#pdf-package.searchers
     searchpath = searchpath,
-    path = concat(load_paths, ';'),
+    path = concat(load_paths or empty_t, ';'),
     cpath = '', -- no C libraries allowed in sandbox
   }