diff --git a/wrapper/piuparts_runner b/wrapper/piuparts_runner
index 19fc24a..c02a754 100755
--- a/wrapper/piuparts_runner
+++ b/wrapper/piuparts_runner
@@ -20,8 +20,8 @@ rm -f piuparts.tap
 
 if [ -n "${PROJECTNAME:-}" ] ; then
   case "${PROJECTNAME}" in
-    metapackages)
-      echo "PROJECTNAME matches metapackages, using /tmp for the piuparts run instead of the tmpfs"
+    metapackages|rainbow-misc)
+      echo "PROJECTNAME is ${PROJECTNAME}, using /tmp for the piuparts run instead of the tmpfs"
       PIUPARTS_BASEDIR="$(sudo mktemp --dry-run -d --tmpdir=/tmp/ --suffix=_piuparts_basetmp)"
       PIUPARTS_TMPDIR="$(sudo mktemp -d --tmpdir=/tmp/ --suffix=_piuparts_tmp)"
       ;;
@@ -36,6 +36,79 @@ echo "*** Using $architecture as \$architecture ***"
 echo "*** Using $distribution as \$distribution ***"
 echo "*** Using $mirror as \$mirror ***"
 
+# set up sources.list, apt-preferences,... for rainbow specific needs
+prepare_rainbow_environment() {
+  # do not operate on original to avoid modifications and problems with simultaneous runs
+  echo "*** Creating copy of /var/cache/pbuilder/base-${distribution}-${architecture}.cow ***"
+  sudo cp -a "/var/cache/pbuilder/base-${distribution}-${architecture}.cow" "${PIUPARTS_BASEDIR}"
+
+  echo "*** Setting up sources.list ***"
+  sudo cp sources.list.d/sources.list   "$PIUPARTS_BASEDIR"/etc/apt/sources.list
+  sudo cp sources.list.d/builddeps.list "$PIUPARTS_BASEDIR"/etc/apt/sources.list.d/
+
+  echo "*** Retrieving latest ngcp-rainbow-keyrings package from release-trunk-${distribution} ***"
+  local packages_tmp
+  packages_tmp=$(mktemp -d)
+  wget --timeout=30 -O "${packages_tmp}"/Packages.gz "https://deb.sipwise.com/autobuild/dists/release-trunk-${distribution}/main/binary-amd64/Packages.gz"
+  # sed: display paragraphs matching the "Package: ..." string, then grab string "^Version: " and display the actual version via awk
+  # sort -u to avoid duplicates in repositories
+  local version
+  version=$(zcat "${packages_tmp}"/Packages.gz | sed "/./{H;\$!d;};x;/Package: ngcp-rainbow-keyrings-pro/b;d" | awk '/^Version: / {print $2}' | sort -u)
+  rm -rf "${packages_tmp}"
+
+  if [ -z "${version:-}" ] ; then
+    echo "Error: ngcp-rainbow-keyrings-pro version for release-trunk-${distribution} could not be detected." >&2
+    exit 1
+  fi
+
+  local deb_package="ngcp-rainbow-keyrings-pro_${version}_all.deb"
+  if ! sudo wget --timeout=30 -O "${PIUPARTS_BASEDIR}"/root/"${deb_package}" "https://deb.sipwise.com/autobuild/pool/main/n/ngcp-rainbow-misc/${deb_package}" ; then
+    echo "Error: failed to download ngcp-rainbow-keyrings-pro Debian package" >&2
+    exit 1
+  fi
+
+  echo "*** Installing ngcp-rainbow-misc package inside cowbuilder environment for keyring files ***"
+  if ! sudo chroot "${PIUPARTS_BASEDIR}" dpkg -i /root/"${deb_package}" ; then
+    echo "Error: failed to install ${deb_package} inside ${PIUPARTS_BASEDIR}" >&2
+    exit 1
+  fi
+
+  echo "*** Setting up /etc/apt/sources.list.d/rainbow.list ***"
+  cat << EOF | sudo tee "${PIUPARTS_BASEDIR}"/etc/apt/sources.list.d/rainbow.list
+# installed via piuparts-tests.git / wrapper/piuparts_runner on the fly
+deb [signed-by=/usr/share/keyrings/rainbow.pgp] http://deb.rainbow.sipwise.com/rainbow bullseye-lts main non-free
+deb [signed-by=/usr/share/keyrings/mongodb.pgp] http://deb.rainbow.sipwise.com/mongodb stretch/mongodb-org/3.6 main
+EOF
+
+  if ! [ -r "${PIUPARTS_BASEDIR}"/bin/systemctl ] ; then
+    echo "*** Faking availability of systemctl tool for cloud-wrg/mongodb-org-server packages ***"
+    sudo ln -s /bin/true "${PIUPARTS_BASEDIR}"/bin/systemctl
+  fi
+
+  echo "*** Setting up apt_preferences ***"
+  if [ -f sources.list.d/preferences ] ; then
+    sudo cp sources.list.d/preferences "$PIUPARTS_BASEDIR"/etc/apt/preferences
+  else
+    cat << EOF | sudo tee "$PIUPARTS_BASEDIR"/etc/apt/preferences
+Package: *
+Pin: release o=Sipwise
+Pin-Priority: 990
+
+Package: *
+Pin: release o=The Sipwise VoIP platform
+Pin-Priority: 990
+
+Package: *
+Pin: release o=mongodb
+Pin-Priority: 600
+
+Package: *
+Pin: release o=Rainbow R&D
+Pin-Priority: 600
+EOF
+  fi
+}
+
 # set up sources.list, apt-preferences,... as needed
 prepare_environment() {
   # do not operate on original to avoid modifications and problems with simultaneous runs
@@ -155,7 +228,14 @@ RUN_LICENSE_CLIENT=false # by default assume we don't have the ngcp-license-clie
 find artifacts/ -name 'ngcp-license-client*' | grep -q '.' && RUN_LICENSE_CLIENT=true
 
 # prepare environment for piuparts
-prepare_environment
+case "${PROJECTNAME}" in
+  rainbow-misc)
+    prepare_rainbow_environment
+    ;;
+  *)
+    prepare_environment
+    ;;
+esac
 
 if [ "$RUN_NGCP_SUPPORT_PACKAGES" = "true" ] ; then
   echo "*** Found ngcp-support specific packages, executing ngcp_support_packages ***"