cleanup docker files and build/test procedure

docker/centos-8.Dockerfile

@@ -0,0 +1,35 @@
+FROM centos:8
+
+ARG mscpdir="/mscp"
+
+COPY . ${mscpdir}
+
+# from https://stackoverflow.com/questions/70963985/error-failed-to-download-metadata-for-repo-appstream-cannot-prepare-internal
+RUN cd /etc/yum.repos.d/
+RUN sed -i 's/mirrorlist/#mirrorlist/g' /etc/yum.repos.d/CentOS-*
+RUN sed -i 's|#baseurl=http://mirror.centos.org|baseurl=http://vault.centos.org|g' /etc/yum.repos.d/CentOS-*
+
+# install numpy and pytest, sshd for test, and rpm-build
+RUN set -ex && yum -y update && yum -y install \
+	python3 python3-pip openssh openssh-server openssh-clients rpm-build
+
+RUN python3 -m pip install numpy pytest
+
+
+# preparation for sshd
+RUN  mkdir /var/run/sshd        \
+	&& ssh-keygen -A	\
+        && ssh-keygen -f /root/.ssh/id_rsa -N ""                \
+        && mv /root/.ssh/id_rsa.pub /root/.ssh/authorized_keys
+
+# install build dependency
+RUN ${mscpdir}/scripts/install-build-deps.sh
+
+# build
+RUN cd ${mscpdir}			\
+        && rm -rf build			\
+        && cmake -B build -DBUILD_PKG=1 \
+        && cd ${mscpdir}/build          \
+	&& make				\
+	&& cpack -G RPM CPackConfig.cmake
+