Bug#851556: autopkgtest: please add Restrictions for network access, or Features for lack of network access

[Simon McVittie]

On Mon, 16 Jan 2017 at 12:47:21 +0100, Martin Pitt wrote:
> +Debian's and Ubuntu's production CI infrastructure do allow unrestricted
> +network access (possibly through a proxy).

If it's through a proxy, it isn't unrestricted, because I've never
encountered a proxy that supports more than DNS, TCP and occasionally
UDP.

What operations can tests with no Restrictions rely on?

- DNS resolution via the standard glibc nsswitch APIs?
- HTTP in anything that supports HTTP proxying *and* respects
  the http_proxy environment variable?
- FTP in anything that supports FTP-over-HTTP proxying *and* respects
  the ftp_proxy environment variable?
- TLS to (port 443? arbitrary ports?) in anything that supports HTTP
  CONNECT proxying and respects the https_proxy environment variable?
- Arbitrary TCP to arbitrary ports via HTTP CONNECT and https_proxy?
- SOCKS? (Discovered how?)
- UDP?
- ICMP ping?
- etc.

Regards,
    S