xenial:repogen has been added.

docker/xenial/repogen/.gitignore

+repodir/Packages
+repodir/Release
+repodir/Release.gpg
+

docker/xenial/repogen/Dockerfile

+FROM ubuntu:16.04
+MAINTAINER Mate Farkas <mate.farkas@sch.hu>
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get -y update && apt-get install -y \
+  apt-utils
+
+ADD usr/local/bin/generate-apt-metadata /usr/local/bin/generate-apt-metadata
+RUN chmod a+x /usr/local/bin/generate-apt-metadata
+
+CMD /usr/local/bin/generate-apt-metadata
+

docker/xenial/repogen/Makefile

+TAG='matefarkas/xenial:repogen'
+
+all:
+	docker build --tag ${TAG} ${PWD}
+
+test:
+	docker run -it --rm --volume ${PWD}/repodir/:/build/ --volume ~/.gnupg/:/root/.gnupg/:ro ${TAG}
+

docker/xenial/repogen/README.md

+# matefarkas/xenial:repogen
+
+DEB repo metadata generator.
+
+## alias
+
+    alias repogen-apt='docker run -it --rm --volume $PWD:/build/ --volume ~/.gnupg/:/root/.gnupg/:ro matefarkas/xenial:repogen'
+

docker/xenial/repogen/repodir/indeed.key

+-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: GnuPG v1
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+ulkpoRHCkvxxZccI3JwAOQhaaUDQLJF6dl0Pw9c=
+=D1iS
+-----END PGP PUBLIC KEY BLOCK-----

docker/xenial/repogen/repodir/indeed.list

+deb http://indeed.sch.bme.hu/apt/ /
+

docker/xenial/repogen/usr/local/bin/generate-apt-metadata

+#!/bin/bash
+
+REPO_DIR=/build/
+PERMISSIONS=0444
+
+if [ ! -d $REPO_DIR ]
+then
+  echo "ERROR: ${REPO_DIR} doesn't exist."
+  exit 1
+fi
+
+uid=`stat -c '%u' $REPO_DIR`
+gid=`stat -c '%g' $REPO_DIR`
+
+cd $REPO_DIR
+apt-ftparchive packages $REPO_DIR > Packages
+sed -i "s|^Filename: ${REPO_DIR}|Filename: |" Packages
+apt-ftparchive release  $REPO_DIR > Release
+
+chown $uid:$gid Packages Release
+chmod $PERMISSIONS Packages Release
+
+if [ ! -d ~/.gnupg/ ]
+then
+  echo "ERROR: GPG config is missing."
+  exit 1
+fi
+
+gpg --armor --detach-sign --digest-algo SHA256 --sign --no-random-seed-file --output Release.gpg Release
+chown $uid:$gid Release.gpg
+chmod $PERMISSIONS Release.gpg
+