muhamadazmy/gedis

Gedis

A proof of concept application server that can serve lua applications. It uses gopher-lua

What is done

• Load lua code
• Proxy calls from Go to lua
• Build Go packages/functions that is callable from Lua packages
• Build a RESP (redis) transport so remote clients can call lua functions
• Basic control resp command to list, load, and unload lua packages
• Client sets content-type current only JSON
• Test support for native lua libraries
• Authentication/Authorization
• Package manifest to configure
  • Authentication/Authorization per package (action?)
  • Go packages to be available from Lua package

Resp Transport

While the code base supports replacing and or add support to multiple transport layers, currently only Resp transport is implemented. It works as following

• Resp expose built in functions, and packages functions
• All built it functions are prefixed with ., and they are case insensitive
• Currently the build in functions are
  • .ping response is always PONG
  • .package.list list names of loaded packages
  • .package.add <name> <path> adds lua package add path path with name name
  • .package.remove <name> remove packages name
  • .content-type.get gets current content type (currently only return JSON)
  • .content-type.set sets content type for package method calls inputs and outputs (current only return error not implemented)
• Package functions calls
  • Package functions calls has to be in format <package>.<function> args...
  • arguments must be valid value for selected content-type (currently json)
  • Note: the following examples are done with redis-cli -p 9091
  • for example a call to add function of the calc package must be done as calc.add 1 2 notice that inputs are not quoted because that's how a valid json number is. The return value is always a valid json value. You need to unmarshal the returned data to get a valid type.
  • for a bit of a more complex example, the db package
    • db.set and db.get always require a string key
    • db.set '"key"' '"string value" sets value to string value
    • db.set '"key"' 123 sets value to numeric value
    • db.get '"key"' returns the last set value to key
    • Note here a valid json string key is "key"

Running the examples

In one terminal do

make run

In another terminal do

redis-cli -p 9091

Then in the redis-cli shell, do:

> .ping
PONG

List loaded packages

> .package.list
1) calc
2) db

Make a call

> calc.add 1 2
"3"
> db.set '"name"' '"test"'
OK
> db.set '"age"' 37
OK
> db.get '"name"'
"\"test\""
> db.get '"age"'
"37

The escape sequence is added by redis-cli for display purpose, with a redis client, you will receive a valid json string that you can unmarshal normally