Apache 2.4 changes things a lot – particularly around authentication and authorisation.

I’m not the first to run into this issue, but I didn’t find a single straight answer online. So here goes (as root):

# add Precise sources so that Apache 2.2 can be used
cat <<EOF >> /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu precise main restricted universe
deb http://archive.ubuntu.com/ubuntu precise-updates main restricted universe
deb http://security.ubuntu.com/ubuntu precise-security main restricted universe multiverse
EOF
# install Apache 2.2 (from the Precise repos)
apt-get install -y apache2-mpm-prefork=2.2.22-1ubuntu1.9 \
  apache2-prefork-dev=2.2.22-1ubuntu1.9 \
  apache2.2-bin=2.2.22-1ubuntu1.9 \
  apache2.2-common=2.2.22-1ubuntu1.9

If you want mpm-worker then do this instead:

# add Precise sources so that Apache 2.2 can be used
cat <<EOF >> /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu precise main restricted universe
deb http://archive.ubuntu.com/ubuntu precise-updates main restricted universe
deb http://security.ubuntu.com/ubuntu precise-security main restricted universe multiverse
EOF
# install Apache 2.2 (from the Precise repos)
apt-get install -y apache2=2.2.22-1ubuntu1.9 \
  apache2.2-common=2.2.22-1ubuntu1.9 \
  apache2.2-bin=2.2.22-1ubuntu1.9 \
  apache2-mpm-worker=2.2.22-1ubuntu1.9