nginx - How to run a shell script on every request?

Question

I want to run a shell script every time my nginx server receives any HTTP request. Any simple ways to do this?

Answer 1

1. Install OpenResty (OpenResty is just an enhanced version of Nginx by means of addon modules ) Refer https://openresty.org/en/getting-started.html for this
2. Configure aws cli on the instance
3. Write a shell script which download a file from specified S3 bucket
4. Do the required changes in nginx.conf file
5. Restart the nginx server

I have tested the http request using curl and file gets download in /tmp directory of respective instance:

curl -I http://localhost:8080/

OutPut:

curl -I http://localhost:8080/
HTTP/1.1 200 OK
Server: openresty/1.13.6.2
Date: Tue, 14 Aug 2018 07:34:49 GMT
Content-Type: text/plain
Connection: keep-alive 

Content of nginx.conf file:

worker_processes  1;
error_log logs/error.log;
events {
    worker_connections 1024;
}
http {
    server {
        listen 8080;
        location / {
           default_type text/html;
           content_by_lua '
                ngx.say("
hello, world
")
           ';
        }

        location / {
            content_by_lua_block{
            os.execute("sh /tmp/s3.sh")
            }
        }

    }
}