Curator

A python helper to make it easier to work with lua scripts in redis.

Inspired by/python port of Shopify's wolverine.

Usage

1) Ensure you have redis 2.6 or higher installed:

redis-server -v

2) Install curator:

pip install https://github.com/mhahn/curator.git@0.0.1

3) Add your lua scripts to a directory, ie:

-- app/lua_scripts/util/mexists.lua
local exists = {}
local existence
for _, key in ipairs(KEYS) do
  table.insert(exists, redis.call('exists', key))
end
return exists

4) Configure and call Curator in your code:

from redis import Redis
from curator import Curator

# this should happen when you start your server
curator = Curator(
    package='app',
    scripts_dir='lua_scripts',
    redis_client=Redis(),
)

print curator.util.mexists(keys=['key1', 'key2', 'key3'])
# [0, 1, 0]

Methods are available on curator based on the directory structure of the scripts_dir.

Nested Lua Scripts

For lua scripts with shared code, Curator supports jinja templating.

If your app has lua scripts at

• app/lua_scripts/do_something.lua
• app/lua_scripts/do_something_else.lua

that both have shared lua code, you can factor it out into a lua "partial":

• app/lua_scripts/shared/_common.lua

-- app/lua_scripts/shared/_common.lua
local function complex_redis_command(key, value)
  local dict = {}
  dict[key] = value
end

-- app/lua_scripts/do_something.lua
{% include 'shared/_common.lua' %}
complex_redis_command("foo", "bar")
return true

-- app/lua_scripts/do_something_else.lua
{% include 'shared/_common.lua' %}
complex_redis_command("bar", "baz")
return false

• partials are loaded relative to the scripts_dir location you instantiate Curator with.

More information

For more information on scripting redis with lua, refer to redis' excellent documentation: http://redis.io/commands/eval