1. local headers = ngx.req.get_headers()  
2. ngx.say("headers begin", "<br/>")  
3. ngx.say("Host : ", headers["Host"], "<br/>")  
4. ngx.say("user-agent : ", headers["user-agent"], "<br/>")  
5. ngx.say("user-agent : ", headers.user_agent, "<br/>")  
6. for k,v in pairs(headers) do
7. if type(v) == "table"
8. " : ", table.concat(v, ","), "<br/>")  
9. else
10. " : ", v, "<br/>")  
11.     end  
12. end