dist: add new docker building process

The new process has the following differences from the Dockerfile
based image:

 - Using buildah commands instead of a Dockerfile. This is more flexible
   since we don't need to pack everything into a "build context" and
   transfer it to the container; instead we interact with the container
   as we build it.
 - Using packages instead of a remote yum repository. This makes it
   easy to create an image in one step (no need to create a repository,
   promote, then download the packages back via yum. It means that
   the image cannot be upgraded via yum, but container images are
   usually just replaced with a new version.
 - Build output is an OCI archive (e.g. a tarball), not a docker image
   in a local repoistory. This means the build process can later be
   integrated into ninja, since the artifact is just a file. The file
   can be uploaded into a repository or made available locally with
   skopeo.
 - any build mode is supported, not just release. This can be used
   for quick(er) testing with dev mode.

I plan to integrate it further into the build system, but currently
this is blocked on a buildah bug [1].

[1] https://github.com/containers/buildah/issues/3262

Closes #8730

dist/docker/redhat/build_docker.sh

@@ -0,0 +1,104 @@
+#!/bin/bash -ex
+
+#
+# Copyright (C) 2021-present ScyllaDB
+#
+
+#
+# This file is part of Scylla.
+#
+# Scylla is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Scylla is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+product="$(<build/SCYLLA-PRODUCT-FILE)"
+version="$(<build/SCYLLA-VERSION-FILE)"
+release="$(<build/SCYLLA-RELEASE-FILE)"
+
+mode="release"
+arch="$(uname -m)"
+
+print_usage() {
+    echo "usage: $0 [--mode mode]"
+    exit 1
+}
+
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --mode)
+            mode="$2"
+            shift 2
+            ;;
+        *)
+            print_usage
+            ;;
+    esac
+done
+
+container="$(buildah from docker.io/centos:7)"
+
+packages=(
+    "build/dist/$mode/redhat/RPMS/$arch/$product-$version-$release.$arch.rpm"
+    "build/dist/$mode/redhat/RPMS/$arch/$product-server-$version-$release.$arch.rpm"
+    "build/dist/$mode/redhat/RPMS/$arch/$product-conf-$version-$release.$arch.rpm"
+    "build/dist/$mode/redhat/RPMS/$arch/$product-kernel-conf-$version-$release.$arch.rpm"
+    "build/dist/$mode/redhat/RPMS/$arch/$product-node-exporter-$version-$release.$arch.rpm"
+    "tools/java/build/redhat/RPMS/noarch/$product-tools-$version-$release.noarch.rpm"
+    "tools/java/build/redhat/RPMS/noarch/$product-tools-core-$version-$release.noarch.rpm"
+    "tools/jmx/build/redhat/RPMS/noarch/$product-jmx-$version-$release.noarch.rpm"
+    "tools/python3/build/redhat/RPMS/$arch/$product-python3-$version-$release.$arch.rpm"
+)
+
+bcp() { buildah copy "$container" "$@"; }
+run() { buildah run "$container" "$@"; }
+bconfig() { buildah config "$@" "$container"; }
+
+
+bcp "${packages[@]}" packages/
+
+bcp dist/docker/redhat/etc etc/
+bcp dist/docker/redhat/scylla-service.sh /scylla-service.sh
+bcp dist/docker/redhat/node-exporter-service.sh /node-exporter-service.sh
+bcp dist/docker/redhat/scylla-housekeeping-service.sh /scylla-housekeeping-service.sh
+bcp dist/docker/redhat/scylla-jmx-service.sh /scylla-jmx-service.sh
+bcp dist/docker/redhat/sshd-service.sh /sshd-service.sh
+
+bcp dist/docker/redhat/scyllasetup.py /scyllasetup.py
+bcp dist/docker/redhat/commandlineparser.py /commandlineparser.py
+bcp dist/docker/redhat/docker-entrypoint.py /docker-entrypoint.py
+bcp dist/docker/redhat/node_exporter_install /node_exporter_install
+
+bcp dist/docker/redhat/scylla_bashrc /scylla_bashrc
+
+run yum -y install epel-release
+run yum -y clean expire-cache
+run yum -y update
+run bash -ec "yum -y localinstall packages/*.rpm"
+run yum -y install hostname supervisor openssh-server openssh-clients rsyslog
+run yum -y clean all
+run bash -ec "cat /scylla_bashrc >> /etc/bashrc"
+run mkdir -p /etc/supervisor.conf.d
+run mkdir -p /var/log/scylla
+run /node_exporter_install
+run chown -R scylla:scylla /var/lib/scylla
+
+bconfig --env PATH=/opt/scylladb/python3/bin:/usr/bin:/usr/sbin
+bconfig --entrypoint  "/docker-entrypoint.py"
+bconfig --port 10000 --port 9042 --port 9160 --port 9180 --port 7000 --port 7001 --port 22
+bconfig --volume "/var/lib/scylla"
+
+mkdir -p build/$mode/dist/docker/
+image="oci-archive:build/$mode/dist/docker/$product-$version-$release"
+buildah commit "$container" "$image"
+
+echo "Image is now available in $image."