We were using a bashism in install_packages, but it was
a `/bin/sh` script. This meant there was a syntax error, but
it didn't kill the script so it would loop forever.
Add a test for the install_packages loop by installing something
that doesn't exist. This will trigger the loop, and should hit
the maximum loop count and error out. If it doesn't then the timeout
command will kill it and the test will fail. Using a timeout
isn't ideal, but better than looping forever.
Also clean up the test script a little bit and print a description
of each test before running it.
Sometimes apt will fail due a transient network issue. Often that
will be fixed by retrying.
This is particularly useful as part of an automated build pipeline.
sysv-rc and util-linux are used in the postinst scripts
of some packages, and so those packages won't install
if they aren't available.
sysv-rc contains update-rc.d, so any package that installs
a service would fail to install. Those packages are common
to install in to containers.
util-linux contains the getopt command which some scripts
expect to find.
Some licences require that the binaries be shipped with a copy
of the license. Debian does this in the copyright files in
/usr/share/doc. We need to leave those files there to keep
the image distributable.
James Westby