obs/slapos: bootstrap only in python3

For OSes with python3 older than 3.7, we build python3.7 to bootstrap
buildout.

obs/slapos/debian/control

@@ -4,7 +4,11 @@ Section: net
 Priority: optional
 Build-Depends: debhelper,
                chrpath,
-               python3 (>=3.7) | python
+               python3,
+               libffi-dev,
+               liblzma-dev,
+               libz-dev,
+               libbz2-dev
 Homepage: https://slapos.nexedi.com
 
 Package: slapos-node

obs/slapos/slapos-node/Makefile

@@ -2,7 +2,8 @@
 # -*- makefile -*-
 
 build: 
-	make -C slapos build SLAPOS_BOOTSTRAP_SYSTEM_PYTHON=$(shell which python3 2> /dev/null || echo python2.7)
+	$(eval SLAPOS_BOOTSTRAP_PYTHON := $(shell ./build_python3_if_needed.bash))
+	make -C slapos build SLAPOS_BOOTSTRAP_PYTHON=$(SLAPOS_BOOTSTRAP_PYTHON)
 
 all: build
 

obs/slapos/slapos-node/build_python3_if_needed.bash

+#!/bin/bash
+
+# This script compiles python3.7 if current python3 is older than this
+# It returns the path of the python3 executable to use
+
+version=$(python3 --version | sed 's/Python 3.//' | sed 's/\..*//')
+if [ $version -ge 7 ]
+then
+	echo $(which python3)
+	exit 0
+fi
+
+build_dir=.build
+
+# TODO:how to get this from buildout ?
+python3_url=https://www.python.org/ftp/python/3.7.17/Python-3.7.17.tar.xz
+
+
+md5sum=$(echo -n $python3_url | md5sum | cut -d ' ' -f 1)
+mkdir -p $build_dir
+cp slapos/build/opt/slapos/download-cache/$md5sum $build_dir/$(basename $python3_url)
+cd $build_dir
+tar -xJf $(basename $python3_url)
+rm $(basename $python3_url)
+cd Python*
+sh configure &> /dev/null
+make -j 4 &> /dev/null
+
+echo $(readlink -f python)

obs/slapos/templates/Makefile.in

@@ -23,11 +23,11 @@ build-stamp:
 
 	@echo "Bootstrapping buildout"
 	cd $(BUILD_DIRECTORY) && \
-		$(SLAPOS_BOOTSTRAP_SYSTEM_PYTHON) ./bootstrap-dir/bin/buildout buildout:install-from-cache=true bootstrap
+		$(SLAPOS_BOOTSTRAP_PYTHON) ./bootstrap-dir/bin/buildout buildout:install-from-cache=true bootstrap
 
 	@echo 'Preparing source tarball (recipe version: $(RECIPE_VERSION))'
 	cd $(BUILD_DIRECTORY) && \
-		$(SLAPOS_BOOTSTRAP_SYSTEM_PYTHON) ./bin/buildout -v
+		$(SLAPOS_BOOTSTRAP_PYTHON) ./bin/buildout -v
 
 	@touch build-stamp
 

obs/slapos/templates/slapos.dsc.in

@@ -6,7 +6,7 @@ Version: %VERSION%+%RECIPE_VERSION%+%RELEASE%-1
 Maintainer: Thomas Gambier <thomas.gambier@nexedi.com>
 Homepage: http://slapos.nexedi.com
 Standards-Version: 3.9.2
-Build-Depends: debhelper (>= 4.1.16), chrpath, po-debconf, wget, python3 (>= 3.7) | python, python3-dev (>= 3.7) | python-dev, libssl-dev
+Build-Depends: debhelper (>= 4.1.16), chrpath, po-debconf, wget, python3, python3-dev, libssl-dev, libffi-dev, liblzma-dev, libz-dev, libbz2-dev
 Files: 
  1c2803e4693c74042985d753c9c3ba53 73736102 %SLAPOS_DIRECTORY%.orig.tar.gz
  1c2803e4693c74042985d753c9c3ba53 6102 %SLAPOS_DIRECTORY%-1.diff.tar.gz

obs/slapos/templates/slapos.spec.in

@@ -50,13 +50,14 @@ BuildRequires: patch
 BuildRequires: wget
 BuildRequires: chrpath
 BuildRequires: openssl-devel
-%if 0%{?centos_version} <= 700 || 0%{?rhel_version} <= 700 || 0%{?suse_version} < 1300 || 0%{?sle_version} < 130000
-BuildRequires: python
-BuildRequires: python-devel
-%else
 BuildRequires: python3
 BuildRequires: python3-devel
-%endif
+# dependencies for compilation of python3
+BuildRequires: libffi-devel
+BuildRequires: (lzma-devel or liblzma-devel or xz-devel)
+BuildRequires: zlib-devel
+BuildRequires: (libbz2-devel or bzip2-devel)
+
 Requires: gcc-c++
 Requires: make
 Requires: patch