1.2 OpenResty

1. What It Is

Nginx enhanced with Lua. Lua can be used to access MySQL, Redis, HTTP, and so on.

2. Installation

• OpenResty - Installation
• Lua: download

2.1. Common Lua Components

• OpenResty - Components

3. Lua Basics

Lua

4. OpenResty Packages

4.1. HTTP

• Request line

-- Get GET request parameters
local arg=ngx.req.get_uri_args()
for k,v in pairs(arg) do
    ngx.say("[GET] key:",k," v:",v)
    ngx.say("line break")
end

-- Get request parameters for a POST request
ngx.req.read_body() -- The body must be read before parsing body parameters
local arg = ngx.req.get_post_args()
for k,v in pairs(arg) do
    ngx.say("[POST] key:",k," v:",v)
    ngx.say("<br>")
end

• Request headers

-- Get headers
local headers = ngx.req.get_headers()
for k,v in pairs(headers) do
    ngx.say("[header] name;",k," v:",v)
    ngx.say("<br>")
end

• Request body

-- Get body information
local data = ngx.req.get_body_data()
ngx.say(data)
ngx.req.get_body_data() -- The request body may occasionally be unreadable and return nil directly. If the request body has not yet been read, call ngx.req.read_body() first (or enable lua_need_request_body to force this module to read the request body; this method is not recommended).

5. References

• OpenResty High-Performance Billion-Scale Product Detail Pages (with Introductory Video)