update for focal, also to support source mirror

Dockerfile

@@ -3,11 +3,27 @@ FROM phusion/baseimage:0.11
 VOLUME /var/mirror
 
 ENV MIRROR_ARCHITECTURES amd64
-ENV SOURCE_MIRROR
+ENV UBUNTU_SOURCE_MIRROR
 ENV MIRROR_CATEGORIES main,universe,restricted,multiverse
 ENV UBUNTU_MIRROR_SOURCE archive.ubuntu.com
 ENV UBUNTU_MIRROR_PROJECTS bionic,bionic-updates,bionic-security,bionic-backports,focal,focal-updates,focal-security,focal-backports
 
+# The following is the URL populated in /mirrors.txt as used by mirror://
+# protocol scheme in sources.list
+# the idea is that you can DNS rewrite 'mirrors.ubuntu.com' to this mirror
+# and it will return a "list" of mirrors that includes only itself.
+# then you can safely use something like the following in your sources.list
+# and it will work with max speed on your own dns-rewritten lan and in the
+# unmodified datacenter talking to the real mirrors.ubuntu.com:
+#
+# MURM="main universe restricted multiverse"
+# C="$(lsb_release -cs)"
+# M="mirror://mirrors.ubuntu.com/mirrors.txt"
+# echo "deb $M $C $MURM" > /etc/apt/sources.list.new
+# echo "deb $M $C-updates $MURM" >> /etc/apt/sources.list.new
+# echo "deb $M $C-backports $MURM" >> /etc/apt/sources.list.new
+# echo "deb $M $C-security $MURM" >> /etc/apt/sources.list.new
+# mv /etc/apt/sources.list.new /etc/apt/sources.list
 ENV THIS_MIRROR_URL http://172.17.0.1/ubuntu/
 
 ADD ./sources.list /etc/apt/sources.list

mirror/syncubuntu.sh

@@ -4,19 +4,24 @@ set -x
 THISDIR="$(cd $(dirname "$BASH_SOURCE") && pwd -P)"
 DST="/var/mirror"
 
-echo "http://172.17.0.1/ubuntu/" > $DST/mirrors.txt
+echo "$THIS_MIRROR_URL" > $DST/mirrors.txt
 chmod a+r $DST/mirrors.txt
 
 mkdir -p "$DST/ubuntu"
 
 export GNUPGHOME="/etc/debmirror/ubuntu"
 
+SOURCEOPT="--nosource"
+if [[ ! -z "$UBUNTU_SOURCE_MIRROR" ]]; then
+    SOURCEOPT="--source"
+fi
+
 debmirror \
-	-a ${MIRROR_ARCHITECTURES:-amd64} \
-	--no-source \
-	-s ${MIRROR_CATEGORIES:-main,universe,multiverse,restricted} \
-	-h ${UBUNTU_MIRROR_SOURCE:-archive.ubuntu.com} \
-	-d ${UBUNTU_MIRROR_PROJECTS:-focal,focal-updates,focal-security,focal-backports} \
+	-a ${MIRROR_ARCHITECTURES} \
+	$SOURCEOPT \
+	-s ${MIRROR_CATEGORIES} \
+	-h ${UBUNTU_MIRROR_SOURCE} \
+	-d ${UBUNTU_MIRROR_PROJECTS} \
     --ignore-small-errors \
 	-r /ubuntu \
     --getcontents \