Create an element to allow using a dpkg manifest

Enable reusing of a dpkg manifest to pin package versions at build
time

Change-Id: I23e83268d282c972b335a8cf0dfc45030a0ab4ff

elements/apt-preferences/README.md

@@ -0,0 +1,6 @@
+# Create package pins for apt systems if packages need to be held back
+
+For APT based systems, you specify package priorities in the apt preferences file.
+This element reads the given manifest file, specified in `DIB_DPKG_MANIFEST`, to
+set pins to enable pinning of older versions for the given packages.
+

elements/apt-preferences/extra-data.d/99-set-apt-package-pins

@@ -0,0 +1,49 @@
+#!/bin/bash
+#
+# Copyright 2014 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+set -eu
+set -o pipefail
+
+# exit directly if DIB_DPKG_MANIFEST is not defined properly
+if [ -z "$DIB_DPKG_MANIFEST" ]; then
+    echo "DIB_DPKG_MANIFEST must be set to the location of a manifest file you wish to use"
+    exit 0
+elif [ ! -f "$DIB_DPKG_MANIFEST" -o ! -s "$DIB_DPKG_MANIFEST" ]; then
+    echo "$DIB_DPKG_MANIFEST is not a valid manifest file."
+    echo "You should assign a proper manifest file in DIB_DPKG_MANIFEST"
+    exit 1
+fi
+
+DIB_DPKG_MANIFEST=$(readlink -f $DIB_DPKG_MANIFEST)
+
+# Create the preferences file from the given manifest
+outfile=$(mktemp)
+for package in $(jq -r ".packages[].package" $DIB_DPKG_MANIFEST); do
+    version=$(jq -r ".packages[] | select(.package == \"${package}\") |\
+        .version" $DIB_DPKG_MANIFEST)
+    cat << EOF >> $outfile
+Package: ${package}
+Pin: version ${version}
+Pin-Priority: 1001
+
+EOF
+done
+
+if [ -s $outfile ]; then
+    sudo mv $outfile $TMP_MOUNT_PATH/etc/apt/preferences
+else
+    rm $outfile
+fi