lua package for yaml support

[nopcoder]

Close #6544

[arielshaqed]

Neat!

Can you just add a note about how to test this manually?

[arielshaqed]

How expensive is this? And... are we sure we are exception-safe and defer x.Close() for all our Closers along the stack?

[nopcoder]

The lua implementation we are using implemented the error handling using raise (panic), as described https://pkg.go.dev/github.com/Shopify/go-lua#Errorf.

Can go over the current provided files and lookup for resource management issues.

[nopcoder]

Neat!

Can you just add a note about how to test this manually?

1. Thanks for the review!
2. Sure - I've used the lakefs lua run capability with the following code:

local yaml = require("encoding/yaml")

content = [[
config:
    endpoint: http://localhost:8080
]]

local doc = yaml.unmarshal(content)
print("endpoint: ".. doc.config.endpoint)

local content2 = yaml.marshal(doc)
print("----")
print(content2)
print("----")
if content == content2 then
    print("success :)")
else
    print("failed!")
end