Yes, you can transparently forward all traffic from a given process to mitmproxy by using tools like iptables in combination with network namespaces or proxychains. Below are two common methods to achieve this:

1. Using iptables and Network Namespaces

This approach is more flexible and commonly used for redirecting traffic at the network level without needing to configure each application.

Steps:

1. Create a network namespace for the process you want to isolate.

   ip netns add mynamespace
   

2. Run the process in the namespace.

   ip netns exec mynamespace your_command_here
   

3. Set up iptables to forward traffic to mitmproxy running as a transparent proxy:

   iptables -t nat -A OUTPUT -p tcp --dport 80 -j REDIRECT --to-port 8080
   iptables -t nat -A OUTPUT -p tcp --dport 443 -j REDIRECT --to-port 8080
   

   This forwards HTTP (port 80) and HTTPS (port 443) traffic from the process to mitmproxy (assuming it's running in transparent mode on port 8080).

4. Run mitmproxy in transparent mode.

   mitmproxy --mode transparent --showhost
   

2. Using proxychains

If you want an easier and less isolated setup, you can use proxychains to hook all outgoing traffic from a process and forward it to mitmproxy.

Steps:

1. Install proxychains:

   sudo apt install proxychains
   

2. Configure proxychains to point to your mitmproxy instance: Edit the /etc/proxychains.conf file, adding the following:

   http  127.0.0.1 8080
   

3. Launch your process with proxychains:

   proxychains your_command_here
   

This method works well when mitmproxy is running in HTTP proxy mode.

Both methods work depending on your specific use case, though the network namespace approach offers more control over process isolation and traffic redirection.