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

@@ -1,40 +1,53 @@
-#!/bin/sh
+#!/usr/bin/env bash
 set -e
 
 build_sasl2() {
-    git clone --depth 1 --branch ${SASL_XOAUTH2_GIT_REF} ${SASL_XOAUTH2_REPO_URL} /sasl-xoauth2
-    cd /sasl-xoauth2
-    mkdir build
-    cd build
-    # Documentation build (now) requires pandoc, which is not available on multiple
-    # 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
-    if [ -f /etc/alpine-release ]; then
-        patch -p1 -d .. < /build-scripts/sasl-xoauth2-02.patch
-        cmake -DCMAKE_INSTALL_PREFIX=/ ..
-    else
-        cmake -DCMAKE_INSTALL_PREFIX=/usr ..
-    fi
-    make
-    make install
-    install ../scripts/postfix-sasl-xoauth2-update-ca-certs /etc/ca-certificates/update.d
-    update-ca-certificates
+	git clone --depth 1 --branch ${SASL_XOAUTH2_GIT_REF} ${SASL_XOAUTH2_REPO_URL} /sasl-xoauth2
+	cd /sasl-xoauth2
+	mkdir build
+	cd build
+	# Documentation build (now) requires pandoc, which is not available on multiple
+	# 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=/ ..
+	else
+		cmake -DCMAKE_INSTALL_PREFIX=/usr ..
+	fi
+	make
+	make install
+	install ../scripts/postfix-sasl-xoauth2-update-ca-certs /etc/ca-certificates/update.d
+	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
-    build_sasl2
-    apk del .build-deps;
+	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"
-    apt-get install -y --no-install-recommends ${LIBS}
-    build_sasl2
-    apt-get remove --purge -y ${LIBS}
-    apt-get autoremove --yes
-    apt-get clean autoclean
+	apt-get update -y -qq
+	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
+	apt-get clean autoclean
 fi
 

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 -*-