travis: add eoan CI builder for hwloc 2 coverage

.travis.yml

@@ -29,6 +29,12 @@ matrix:
        - ARGS="--prefix=/usr"
        - TEST_INSTALL=t
        - DOCKER_TAG=t
+    - name: "Ubuntu: 20.04"
+      compiler: gcc
+      env:
+        - ARGS="--prefix=/usr"
+        - IMG=focal
+        - DOCKER_TAG=t
     - name: "Centos 7: docker-deploy"
       compiler: gcc
       env:

src/test/docker/focal/Dockerfile

@@ -0,0 +1,29 @@
+FROM fluxrm/flux-core:focal
+
+ARG USER=flux
+ARG UID=1000
+
+# Install extra buildrequires for flux-sched:
+RUN sudo apt-get update
+RUN sudo apt-get -qq install -y --no-install-recommends \
+	libboost-graph-dev \
+	libboost-system-dev \
+	libboost-filesystem-dev \
+	libboost-regex-dev \
+	libxml2-dev \
+	python-yaml \
+	libyaml-cpp-dev
+
+# Add configured user to image with sudo access:
+#
+RUN \
+ if test "$USER" != "flux"; then  \
+      sudo groupadd -g $UID $USER \
+   && sudo useradd -g $USER -u $UID -d /home/$USER -m $USER \
+   && sudo sh -c "printf \"$USER ALL= NOPASSWD: ALL\\n\" >> /etc/sudoers" \
+   && sudo adduser $USER sudo ; \
+ fi
+
+USER $USER
+WORKDIR /home/$USER
+RUN flux keygen