Configure apt and update index

This script configures apt to use a proxy (if VM_PROXY is set), adds the
ubuntu-cloud repo (release set by OPENSTACK_RELEASE) and updates the apt
index.

Partial-Bug: 1312764
Implements: blueprint openstack-training-labs
Change-Id: I6a426ee31746424a761fc8cd6d81723ac7740f04

labs/scripts/apt_init.sh

@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+TOP_DIR=$(cd $(dirname "$0")/.. && pwd)
+source "$TOP_DIR/config/paths"
+source "$CONFIG_DIR/openstack"
+# Pick up VM_PROXY
+source "$CONFIG_DIR/localrc"
+source "$LIB_DIR/functions.guest"
+
+indicate_current_auto
+
+exec_logfile
+
+function set_apt_proxy {
+    local PRX_KEY="Acquire::http::Proxy"
+    local APT_FILE=/etc/apt/apt.conf
+
+    if [ -f $APT_FILE ] && grep -q $PRX_KEY $APT_FILE; then
+        # apt proxy has already been set (by preseed/kickstart)
+        if [ -n "${VM_PROXY-}" ]; then
+            # Replace with requested proxy
+            sudo sed -i "s#^\($PRX_KEY\).*#\1 \"$VM_PROXY\";#" $APT_FILE
+        else
+            # No proxy requested -- remove
+            sudo sed -i "s#^$PRX_KEY.*##" $APT_FILE
+        fi
+    elif [ -n "${VM_PROXY-}" ]; then
+        # Proxy requested, but none configured: add line
+        echo "$PRX_KEY \"$VM_PROXY\";" | sudo tee -a $APT_FILE
+    fi
+}
+
+set_apt_proxy
+
+# Get apt index files
+sudo apt-get update
+
+# cloud-keyring to verify packages from ubuntu-cloud repo
+sudo apt-get install ubuntu-cloud-keyring
+
+# Install packages needed for add-apt-repository
+sudo apt-get -y install software-properties-common python-software-properties
+sudo add-apt-repository -y "cloud-archive:$OPENSTACK_RELEASE"
+
+# Get index files only for ubuntu-cloud repo but keep standard lists
+sudo apt-get update \
+    -o Dir::Etc::sourcelist="sources.list.d/cloudarchive-$OPENSTACK_RELEASE.list" \
+    -o Dir::Etc::sourceparts="-" -o APT::Get::List-Cleanup="0"