Jossef Harush Kadouri's questions

I'm trying to figure out how to build a DNS response that refers the requesting client to try resolve from a different DNS server.

For example,

1. Client PC makes a request to resolve A record "google.com" from DNS server #1
2. DNS server #1 reply with a referral to DNS server #2
3. Client PC makes a request to resolve A record "google.com" from DNS server #2
4. DNS server #2 reply with a matching A record for "google.com"

How to build a DNS response that refers the client to try resolve from a different DNS server?

Note - I know the best practice is to set the DNS server to recurse the request. However, I purposely want the client to do the hard work.

I'm hosting a simple wsgi application on httpd over CentOS 7 using mod_wsgi and trying to remove the isolation illustrated below.

The wsgi app,

The following script is my wsgi application.

• it creates a file called /tmp/test-wsgi.txt
• enumerates the content of /tmp as a simple json list

code:

def application(environ, start_response):
    status = '200 OK'
    headers = [('Content-Type', 'application/json')]
    start_response(status, headers)

    with open('/tmp/test-wsgi.txt', 'w+') as w:
        w.write('hello world')

    files = os.listdir('/tmp')
    return json.dumps(files)

When i'm accessing my web application i'm getting the following response

["test-wsgi.txt"]

Great so far!

However,

Connected to the same hosting server as root,

I've opened a shell and executed cat /tmp/test-wsgi.txt

From playing around with it, seems that any filesystem operation (enumeration/creation/socket access) inside my wsgi script is "environmently isolated" (like chroot jail). the strange thing is i haven't configured any of that type of isolation.

httpd config

/etc/httpd/conf.d/my-app.conf

<VirtualHost *:80>

DocumentRoot /opt/my-app/

WSGIScriptAlias / /opt/my-app/apache/wsgi.py

<Directory /opt/my-app/apache>
    Order allow,deny
    Allow from all
    Require all granted
</Directory>

</VirtualHost>

/etc/httpd/conf/httpd.conf

...

User apache
Group apache

...