Fix for installation of msal library

This will create a python venv and point sasl-xoauth2-tool to use
this venv. This way, when the user executes the command, it will
"automagically" work instead of failing.

Dockerfile

@@ -34,8 +34,6 @@ ARG TARGETPLATFORM
 ARG SASL_XOAUTH2_REPO_URL=https://github.com/tarickb/sasl-xoauth2.git
 ARG SASL_XOAUTH2_GIT_REF=release-0.25
 
-#           --mount=type=cache,target=/var/cache/apk,sharing=locked,id=var-cache-apk-$TARGETPLATFORM \
-#           --mount=type=cache,target=/etc/apk/cache,sharing=locked,id=etc-apk-cache-$TARGETPLATFORM \
 RUN        --mount=type=cache,target=/var/cache/apt,sharing=locked,id=var-cache-apt-$TARGETPLATFORM \
            --mount=type=cache,target=/var/lib/apt,sharing=locked,id=var-lib-apt-$TARGETPLATFORM \
            --mount=type=tmpfs,target=/etc/apk/cache \

build-scripts/sasl-build.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 set -e
 
 build_sasl2() {
@@ -10,6 +10,11 @@ build_sasl2() {
 	# architectures. Since we're are building an image that we want it to be as slim as possible,
 	# we're removing the build of documentation instead of complicating things with pandoc.
 	patch -p1 -d .. < /build-scripts/sasl-xoauth2-01.patch
+
+	# Ensure that the sasl-xoauth2-tool uses python from the virtual environment into which we
+	# installed the msal library.
+	patch -p1 -d .. < /build-scripts/sasl-xoauth2-03.patch
+
 	if [ -f /etc/alpine-release ]; then
 		patch -p1 -d .. < /build-scripts/sasl-xoauth2-02.patch
 		cmake -DCMAKE_INSTALL_PREFIX=/ ..
@@ -22,16 +27,24 @@ build_sasl2() {
 	update-ca-certificates
 }
 
+setup_python_venv() {
+	python3 -m venv /sasl
+	. /sasl/bin/activate
+	pip3 install msal
+}
+
 [ -f /etc/lsb-release ] && . /etc/lsb-release
 [ -f /etc/os-release ] && . /etc/os-release
 if [ -f /etc/alpine-release ]; then
 	apk add --upgrade --virtual .build-deps git cmake clang make gcc g++ libc-dev pkgconfig curl-dev jsoncpp-dev cyrus-sasl-dev patch
+	setup_python_venv
 	build_sasl2
 	apk del .build-deps;
 else
 	apt-get update -y -qq
-    LIBS="git build-essential cmake pkg-config libcurl4-openssl-dev libssl-dev libjsoncpp-dev libsasl2-dev"
+	LIBS="git build-essential cmake pkg-config libcurl4-openssl-dev libssl-dev libjsoncpp-dev libsasl2-dev python3-venv"
 	apt-get install -y --no-install-recommends ${LIBS}
+	setup_python_venv
 	build_sasl2
 	apt-get remove --purge -y ${LIBS}
 	apt-get autoremove --yes

build-scripts/sasl-xoauth2-03.patch

@@ -0,0 +1,7 @@
+--- sasl-xoauth2-orig/scripts/sasl-xoauth2-tool.in	2025-03-01 08:38:07
++++ sasl-xoauth2/scripts/sasl-xoauth2-tool.in	2025-03-01 08:38:12
+@@ -1,4 +1,4 @@
+-#!/usr/bin/python3
++#!/sasl/bin/python3
+ # PYTHON_ARGCOMPLETE_OK
+ # -*- coding: utf-8 -*-