auto-apt-proxy - autodetect common APT proxy setups
auto-apt-proxy
auto-apt-proxy [COMMAND [ARGS ...]]
auto-apt-proxy is an APT proxy autodetector, and detects common setups by checking localhost, your gateway and other "interesting" machines on your network for well-known APT proxies such as apt-cacher-ng and others.
When called with no arguments, auto-apt-proxy simply prints the address of a detected proxy to the standard output. This package installs an APT configuration file that makes APT use auto-apt-proxy to detect a proxy on every invocation of APT.
When called with arguments, they are assumed to be a command. Such command will be executed with the common environment variables used for specifying HTTP proxies (http_proxy, HTTP_PROXY) set to the detected proxy. This way the executed command will be able to transparently use any detected APT proxy. Note that for this to work, any programs invoked by the given command must have their own support for detecting HTTP proxies from those environment variables, and for using them.
When your apt proxy is installed on localhost or your default gateway, it should Just Work. If you install it somewhere else, you can create an explicit SRV record to tell auto-apt-proxy about it.
Suppose your corporate domain is "example.com", and apt-cacher-ng is installed on "apt-cacher-ng.example.com", and auto-apt-proxy is installed on "alices-laptop.example.com".
The appropriate SRV record in dnsmasq.conf would look like this:
srv-host=_apt_proxy._tcp.example.com,apt-cacher-ng.example.com,3142
The appropriate nsd/bind zonefile entry would look like this (untested):
_apt_proxy._tcp.@ IN SRV 0 0 3142 apt-cacher-ng.@
As an alternative to an SRV record, one can also define a special hostname which needs to be resolved via DNS or local /etc/hosts file, called apt-proxy. For example, if your network has a local apt proxy at 9.9.9.9, then add this line to /etc/hosts:
9.9.9.9 apt-proxy
If avahi-browse is installed, then auto-apt-proxy will try to find any
proxies announced via mDNS. If, for some reason, you would prefer the name of
the announced proxy to be resolved via NSS rather than the somewhat arbitrary
order provided by Avahi, you can set AUTO_APT_PROXY_AVAHI_NAME environment
variable to any non-empty string. AUTO_APT_PROXY_AVAHI_NAME does not change
which proxy is used if multiple mDNS provided proxies are available.
By default, auto-apt-proxy will cache its results for 60 seconds.
To disable the cache, set the AUTO_APT_PROXY_NO_CACHE environment variable to
any non-empty string.
$ auto-apt-proxy
Just prints the detected APT proxy
$ auto-apt-proxy debootstrap sid /my/chroot
Creates a new Debian chroot downloading packages from the local proxy.
Copyright (C) 2016-2020 Antonio Terceiro
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.