Add support for Ubuntu 20.04 (Focal Fossa)

Signed-off-by: Krzysztof Wilczyński <kw@linux.com>

README.md

@@ -10,6 +10,7 @@ Currently supported images:
 - Ubuntu 14.04 "Trusty Tahr" (version: 14.04.6)
 - Ubuntu 16.04 "Xenial Xerus" (version: 16.04.6)
 - Ubuntu 18.04 "Bionic Beaver" (version: 18.04.4)
+- Ubuntu 20.04 "Focal Fossa" (version: 20.04)
 
 Up to date Vagrant boxes can be found at https://app.vagrantup.com/kwilczynski.
 
@@ -22,6 +23,7 @@ Some of the features that the images include:
 - Backported version of Apt for 12.04
 - More recent version of OpenSSL
 - Native ZFS support (only 14.04 and 16.04)
+- Snapcraft support has been removed from 20.04
 
 Every Vagrant box includes an up-to-date version of VirtualBox Guest Additions, and a very basic system tuning (e.g.
 network stack, virtual memory, etc.), plus sensible hardening (e.g. Kernel, OpenSSH, etc.).

http/proxmox/ubuntu-20.04/preseed.cfg

@@ -0,0 +1,8 @@
+d-i preseed/include string ../../common/preseed.cfg ../preseed.cfg
+
+d-i pkgsel/include string openssh-server build-essential libssl-dev libreadline-dev zlib1g-dev linux-source dkms qemu-guest-agent
+
+d-i preseed/late_command string \
+    in-target sed -i -e 's/GRUB_CMDLINE_LINUX_DEFAULT="\(.*\)"/GRUB_CMDLINE_LINUX_DEFAULT="\1 net.ifnames=0 biosdevname=0"/g' /etc/default/grub; \
+    in-target sed -i -e 's/\(enp0\|ens[0-9]\)[a-z0-9]\+/eth0/g' /etc/netplan/01-netcfg.yaml; \
+    in-target update-grub;

http/vagrant/ubuntu-20.04/preseed.cfg

@@ -0,0 +1,8 @@
+d-i preseed/include string ../../common/preseed.cfg ../preseed.cfg
+
+d-i pkgsel/include string openssh-server build-essential libssl-dev libreadline-dev zlib1g-dev linux-source dkms nfs-common
+
+d-i preseed/late_command string \
+    in-target sed -i -e 's/GRUB_CMDLINE_LINUX_DEFAULT="\(.*\)"/GRUB_CMDLINE_LINUX_DEFAULT="\1 net.ifnames=0 biosdevname=0"/g' /etc/default/grub; \
+    in-target sed -i -e 's/\(enp0\|ens[0-9]\)[a-z0-9]\+/eth0/g' /etc/netplan/01-netcfg.yaml; \
+    in-target update-grub;

scripts/common/clean-up.sh

@@ -320,6 +320,9 @@ if [[ ! $UBUNTU_VERSION =~ ^(12|14).04$ ]]; then
     ln -sf /dev/null /etc/systemd/network/99-default.link
 fi
 
+# Ubuntu 18.04 and newer.
+rm -f /etc/netplan/50-cloud-init.yaml
+
 rm -Rf /dev/.udev \
        /var/lib/{dhcp,dhcp3}/* \
        /var/lib/dhclient/*

scripts/common/docker.sh

@@ -19,9 +19,14 @@ readonly AMAZON_EC2=$(detect_amazon_ec2 && echo 'true')
 #  https://www.docker.com/blog/changes-dockerproject-org-apt-yum-repositories/
 cat <<EOF > /etc/apt/sources.list.d/docker.list
 $(if [[ $UBUNTU_VERSION == '12.04' ]]; then
-echo "deb [arch=amd64] https://ftp.yandex.ru/mirrors/docker ubuntu-${UBUNTU_RELEASE} main"
+    echo "deb [arch=amd64] https://ftp.yandex.ru/mirrors/docker ubuntu-${UBUNTU_RELEASE} main"
 else
-echo "deb [arch=amd64] https://download.docker.com/linux/ubuntu ${UBUNTU_RELEASE} stable"
+    if [[ $UBUNTU_VERSION =~ ^(14|16|18).04$ ]]; then
+        echo "deb [arch=amd64] https://download.docker.com/linux/ubuntu ${UBUNTU_RELEASE} stable"
+    else
+        # Starting from 20.04, Docker no long provides packages from their repository.
+        echo "deb [arch=amd64] https://download.docker.com/linux/ubuntu bionic stable"
+    fi
 fi)
 EOF
 
@@ -58,11 +63,21 @@ apt-get --assume-yes update \
 PACKAGES=(
     'pciutils'
     'procps'
-    'btrfs-tools'
     'xfsprogs'
     'git'
 )
 
+if [[ $UBUNTU_VERSION =~ ^(12|14|16|18).04$ ]]; then
+    PACKAGES+=(
+        'btrfs-tools'
+    )
+else
+    # Starting from 20.04, btrfs-progs is no longer a virtual package.
+    PACKAGES+=(
+        'btrfs-progs'
+    )
+fi
+
 DOCKER_PACKAGE='docker-ce'
 if [[ $UBUNTU_VERSION == '12.04' ]]; then
     DOCKER_PACKAGE='docker-engine'