Installing the Flash plug-in on Ubuntu from behind a proxy

There is a package for the Adobe Flash Player plug-in for Mozilla-based browsers in the Ubuntu repositories. If you install the package it downloads the plug-in directly from Adobe and installs it on your system. I tried to do this on a machine behind a proxy that requires authentication and it failed, despite having set up the proxy details in Synaptic, as well as in an http_proxy environment variable for both my user account and the root account in the respective .bashrc files.

There’s probably an easier way to do this, but to get around the problem I manually edited the flashplugin-nonfree.postinst file in /var/lib/dpkg/info following the failed installation attempt.  This file is a shell script, part of which sets up a wgetrc file for use by wget when downloading the plugin from the Adobe website.  As root, add a section for your http proxy in here, something like as follows:

# setting wget options
:> wgetrc
echo "noclobber = off" >> wgetrc
echo "dir_prefix = ." >> wgetrc
echo "dirstruct = off" >> wgetrc
echo "verbose = on" >> wgetrc
echo "progress = dot:default" >> wgetrc
echo "http_proxy=http://user:passwd@proxy.tld:port" >> wgetrc

Then in Synaptic you can mark the flashplugin-nonfree package for reinstallation and it should download and install without further problems.

You may be able to download the package (apt-get -d?), unpack it manually, edit the postinst file, then install to avoid having to sit through a failed attempt at installing first – I haven’t tried this myself. UPDATE – I have now – see Hacking .deb files.