But that wouldn't work, right? If the proxy is on another server then editing their own /etc/hosts wouldn't change the proxy's behavior. So the proxy has to be colocated and reading the same /etc/hosts that they're editing. But that would mean it's running within the same userns/pid domain as the agents, so at that point they don't even need to edit /etc/hosts, they could just use the network directly.

And the agent says ABS is not handled by the proxy, it's listed in NO_PROXY so they should connect directly.

At any rate it's easy to let agents install packages without giving them root. I use a small SUID binary that just invokes `apt install` after checking that the given argument isn't a file path, which I think is sufficient (using sudo to whitelist a prefix allows an agent to create a .deb themselves and then install it directly via apt, similar issues exist for other package managers).