feat(image): Add ubuntu 20.04 image

This PR is too add ubuntu 20.04 image.
Dockerfile is copied from 18.04.

Closes #248

Signed-off-by: Tam Mach <sayboras@yahoo.com>

README.md

@@ -111,6 +111,7 @@ images are:
 - `quay.io/footloose/fedora29`
 - `quay.io/footloose/ubuntu16.04`
 - `quay.io/footloose/ubuntu18.04`
+- `quay.io/footloose/ubuntu20.04`
 - `quay.io/footloose/amazonlinux2`
 - `quay.io/footloose/debian10`
 - `quay.io/footloose/clearlinux`

images/ubuntu20.04/Dockerfile

@@ -0,0 +1,43 @@
+FROM ubuntu:20.04
+
+ENV container docker
+
+# Don't start any optional services except for the few we need.
+RUN find /etc/systemd/system \
+    /lib/systemd/system \
+    -path '*.wants/*' \
+    -not -name '*journald*' \
+    -not -name '*systemd-tmpfiles*' \
+    -not -name '*systemd-user-sessions*' \
+    -exec rm \{} \;
+
+RUN apt-get update && \
+    apt-get install -y \
+    dbus systemd openssh-server net-tools iproute2 iputils-ping curl wget vim-tiny sudo && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/*
+
+RUN >/etc/machine-id
+RUN >/var/lib/dbus/machine-id
+
+EXPOSE 22
+
+RUN systemctl set-default multi-user.target
+RUN systemctl mask \
+      dev-hugepages.mount \
+      sys-fs-fuse-connections.mount \
+      systemd-update-utmp.service \
+      systemd-tmpfiles-setup.service \
+      console-getty.service
+RUN systemctl disable \
+      networkd-dispatcher.service
+
+# This container image doesn't have locales installed. Disable forwarding the
+# user locale env variables or we get warnings such as:
+#  bash: warning: setlocale: LC_ALL: cannot change locale
+RUN sed -i -e 's/^AcceptEnv LANG LC_\*$/#AcceptEnv LANG LC_*/' /etc/ssh/sshd_config
+
+# https://www.freedesktop.org/wiki/Software/systemd/ContainerInterface/
+STOPSIGNAL SIGRTMIN+3
+
+CMD ["/bin/bash"]

tests/variables.json

@@ -4,6 +4,7 @@
     "centos7",
     "fedora29",
     "ubuntu18.04",
+    "ubuntu20.04",
     "debian10",
     "clearlinux"
   ]