ngx_lua example

user       www www;
worker_processes 2;
error_log  /home/wwwlogs/nginx_error.log crit;
pid           /usr/local/openresty/nginx/logs/nginx.pid;
google_perftools_profiles       /tmp/tcmalloc;
worker_rlimit_nofile 51200;
events {
    use epoll;
    worker_connections 51200;
}
http {
    default_type text/html;

    upstream redis {
        server 127.0.0.1:6379;
        keepalive 1024;
    }

    server {
        listen  8080;
        root    /home/wwwroot;
        index   index.html;
    }

    server {
        listen  80;
        root    /home/wwwroot;
        index   index.html;

        location = /proxy {
            proxy_pass http://127.0.0.1:8080/;
        }

        location = /redis {
            internal;
            set $redis_key $arg_key;
            redis_pass redis;
        }

        location = /redis2 {
            internal;
            set $exptime $arg_exptime;
            set $key $arg_key;
            redis2_query set $key $echo_request_body;
            redis2_query expire $key $exptime;
            redis2_pass redis;
        }

        location / {
            default_type 'text/html';
            set $key $uri;
            set $exptime 300;
            content_by_lua '
                -- work like the srcache module
                local resa = ngx.location.capture("/redis",
                    { method = ngx.HTTP_GET,
                      args = { key = ngx.var.key } })
                if resa.status == 200 then
                    ngx.say(resa.body)
                else
                    local resb = ngx.location.capture("/proxy")
                    if resb.status == ngx.HTTP_OK then
                        ngx.say(resb.body)
                        local resc = ngx.location.capture("/redis2",
                            { method = ngx.HTTP_PUT,
                              body = resb.body,
                              args = { key = ngx.var.key, exptime = ngx.var.exptime } })
                    else
                        ngx.exit(ngx.HTTP_NOT_FOUND)
                    end
                end
                -- update the redis cache from the proxy even the keys get hit
                if not resb then
                    local resb = ngx.location.capture("/proxy")
                    if resb.status == ngx.HTTP_OK then
                        local resc = ngx.location.capture("/redis2",
                            { method = ngx.HTTP_PUT,
                              body = resb.body,
                              args = { key = ngx.var.key, exptime = ngx.var.exptime } })
                    else
                        ngx.exit(ngx.HTTP_NOT_FOUND)
                    end
                end
            ';
        }
    }
}