docs: update of code for Dockerized package building

dh-virtualenv/Dockerfile.build

@@ -7,26 +7,31 @@
 # Build arguments, as provided by 'build.sh'
 ARG DIST_ID="debian"
 ARG CODENAME="stretch"
+ARG PYVERSION="3"
 ARG PKGNAME
 
 # Other build arguments (adapt as needed)
-ARG NODEREPO="node_8.x"
+ARG NODEREPO="node_10.x"
 ARG DEB_POOL="http://ftp.nl.debian.org/debian/pool/main"
 
 ## Start package builder image for the chosen platform
 FROM ${DIST_ID}:${CODENAME} AS dpkg-build
 
 # Pass build args into image scope
 ARG CODENAME
+ARG PYVERSION
 ARG PKGNAME
 ARG NODEREPO
 ARG DEB_POOL
 
 # Install build tools and package build deps including nodejs
-RUN env LANG=C apt-get update -qq -o Acquire::Languages=none \
+RUN ( test "${CODENAME}" = "xenial" \
+        && echo "deb [trusted=yes] http://ppa.launchpad.net/deadsnakes/ppa/ubuntu ${CODENAME} main" \
+            >/etc/apt/sources.list.d/deadsnakes.list || : ) \
+    && env LANG=C apt-get update -qq -o Acquire::Languages=none \
     && env LANG=C DEBIAN_FRONTEND=noninteractive apt-get install \
         -yqq --no-install-recommends -o Dpkg::Options::=--force-unsafe-io \
-        \
+        "" \
         apt-transport-https \
         apt-utils \
         build-essential \
@@ -39,24 +44,28 @@ RUN env LANG=C apt-get update -qq -o Acquire::Languages=none \
         libjs-sphinxdoc \
         libparse-debianchangelog-perl \
         lsb-release \
-        python3 \
-        python3-dev \
-        python3-pip \
+        python${PYVERSION} \
+        python${PYVERSION}-venv \
+        python${PYVERSION}-tk \
+        python${PYVERSION}-dev \
         python3-pkg-resources \
         python3-setuptools \
-        python-virtualenv \
+        python3-venv \
         sphinx-rtd-theme-common \
         tar \
-        \
+        "" \
         libcurl4-openssl-dev \
         libffi-dev \
+        libfontconfig1 \
+        libfreetype6-dev \
         libjpeg-dev \
         libncurses5-dev \
         libncursesw5-dev \
         libssl-dev \
         libxml2-dev \
         libxslt1-dev \
         libyaml-dev \
+        libz-dev \
         libzmq3-dev \
     && ( curl -sL https://deb.nodesource.com/gpgkey/nodesource.gpg.key \
          | env APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=true apt-key add - ) \
@@ -77,14 +86,18 @@ RUN env LANG=C apt-get update -qq -o Acquire::Languages=none \
 # Install updated Python tooling and a current 'dh-virtualenv'
 WORKDIR /dpkg-build
 ADD "${DEB_POOL}/d/dh-virtualenv/dh-virtualenv_1.1-1_all.deb" ./
-RUN dpkg -i --force-unsafe-io --ignore-depends=sphinx-rtd-theme-common *_all.deb \
-    && python3 -m pip install -U pip \
-    && python3 -m pip install -U virtualenv setuptools wheel
+RUN dpkg -i --force-unsafe-io \
+         --ignore-depends=python:any \
+         --ignore-depends=virtualenv \
+         --ignore-depends=sphinx-rtd-theme-common \
+         *_all.deb \
+    && python${PYVERSION} -m easy_install pip \
+    && python${PYVERSION} -m pip install -U setuptools wheel
 
 # Build project and show metadata of built package
 COPY ./ ./
 RUN hr() { printf '\n   %-74s\n' "[$1]" | tr ' ' = ; } \
-    && hr Versions && python3 -m pip --version && dh_virtualenv --version \
+    && hr Versions && python${PYVERSION} -m pip --version && dh_virtualenv --version \
     && sed -i -r \
            -e "1s/(UNRELEASED|unstable|jessie|stretch|xenial|bionic)/$(lsb_release -cs)/g" \
            debian/changelog \

dh-virtualenv/build.sh

@@ -5,6 +5,15 @@
 
 set -e
 
+# If you change this, you MUST also change "debian/control" and "debina/rules"
+PYTHON_MINOR="3.8"  # Deadsnakes version on Ubuntu
+
+# Check build environment
+if ! command which "dh_listpackages" >/dev/null 2>&1; then
+    echo >&2 "ERROR: You must 'apt install debhelper' on the build host."
+    exit 1
+fi
+
 # Get build platform as 1st argument, and collect project metadata
 image="${1:?You MUST provide a docker image name}"; shift
 dist_id=${image%%:*}
@@ -13,15 +22,39 @@ pypi_name="$(./setup.py --name)"
 pypi_version="$(./setup.py --version)"
 pkgname="$(dh_listpackages)"
 tag=$pypi_name-$dist_id-$codename
+staging="$pypi_name-$pypi_version"
+
+build_opts=(
+    -f Dockerfile.build
+    --tag $tag
+    --build-arg "DIST_ID=$dist_id"
+    --build-arg "CODENAME=$codename"
+    --build-arg "PKGNAME=$pkgname"
+)
+
+if test "$dist_id" = "ubuntu"; then
+    build_opts+=( --build-arg "PYVERSION=$PYTHON_MINOR" )
+fi
+
+
+# Create Docker staging directory and apply environment changes
+echo "*** Creating staging directory (sdist)"
+echo "*** Ignore warnings regarding non-matching filters..."
+python3 ./setup.py -q sdist -k
+if test "$dist_id" = "debian"; then
+    sed -i -e "s/python$PYTHON_MINOR/python3/g" "$staging/debian/control"
+fi
+
+mkdir -p build
+rm -rf build/docker.staging 2>/dev/null
+mv "$staging" build/docker.staging
+
 
 # Build in Docker container, save results, and show package info
+echo
+echo "*** Building DEB package (takes a while)"
 rm -f dist/${pkgname}?*${pypi_version//./?}*${codename}*.*
-docker build --tag $tag \
-    --build-arg "DIST_ID=$dist_id" \
-    --build-arg "CODENAME=$codename" \
-    --build-arg "PKGNAME=$pkgname" \
-    -f Dockerfile.build \
-    "$@" .
+docker build "${build_opts[@]}" "$@" build/docker.staging
 mkdir -p dist
 docker run --rm $tag tar -C /dpkg -c . | tar -C dist -x
 ls -lh dist/${pkgname}?*${pypi_version//./?}*${codename}*.*

docs/packaging-howto.rst

@@ -40,6 +40,23 @@ the given platform and existing project metadata is stored into a bunch of varia
 
 .. literalinclude:: ../dh-virtualenv/build.sh
     :language: shell
+    :end-before: Create Docker staging
+
+On Ubuntu, the Deadsnakes packages are used, thus the
+default of the ``PYVERSION`` Docker argument is replaced.
+Since the ``control`` file contains that more detailed version,
+the reverse is done for Debian builds – ``3.x`` is replaced by just ``3``.
+
+To keep this and other possible changes out of git's reach,
+a staging copy of the workdir is created via ``sdist``
+– adding ``-k`` keeps the expanded distribution tree intact, so we can change
+and finally move it to ``build/docker.staging``.
+Creating that copy based on a source distribution also tests that
+such a distribution is complete and buildable, as a welcome side-effect.
+
+.. literalinclude:: ../dh-virtualenv/build.sh
+    :language: shell
+    :start-at: Create Docker staging
     :end-before: Build in Docker
 
 After that prep work, we get to build our package, passing along the needed build arguments.
@@ -51,7 +68,6 @@ Also the package metadata is shown for a quick visual check if everything looks
     :language: shell
     :start-at: Build in Docker
 
-
 .. rubric:: The Dockerfile
 
 This is the start of the Dockerfile, setting up some parameters used in the ``RUN`` instructions,