diff --git a/apache/Dockerfile b/apache/Dockerfile
index c776d5a3..b6daf18c 100644
--- a/apache/Dockerfile
+++ b/apache/Dockerfile
@@ -1,6 +1,6 @@
-FROM httpd:2.4
+FROM httpd:2.4-alpine
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
+RUN apk add --no-cache --update \
     nano \
     openssl \
     gettext
diff --git a/apache/entrypoint.sh b/apache/entrypoint.sh
index e0e16288..763a348b 100644
--- a/apache/entrypoint.sh
+++ b/apache/entrypoint.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # if there's no ssl certificate yet create it
 if [ ! -f "/usr/local/apache2/conf/server.crt" ]; then
diff --git a/docker-compose.yml b/docker-compose.yml
index 4f520ab9..b96cb1ac 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -8,7 +8,7 @@ services:
   # docker-compose -f docker-compose.yml -f compose/nginx.yml -f compose/pgsql.yml -f compose/php.yml up -d pgsql php-7.3
 
   nodejs:
-    image: node:16
+    image: node:16-alpine
     container_name: totara_nodejs
     environment:
       TZ: ${TIME_ZONE}
@@ -28,7 +28,7 @@ services:
       - totara
 
   redis:
-    image: redis
+    image: redis:alpine
     # activate persistency
     command: "redis-server --appendonly yes"
     environment:
@@ -39,7 +39,7 @@ services:
       - totara
 
   memcached:
-    image: memcached
+    image: memcached:alpine
     environment:
       TZ: ${TIME_ZONE}
     networks:
diff --git a/mssql/2017/Dockerfile b/mssql/2017/Dockerfile
index 1951556f..cdcbbc2c 100644
--- a/mssql/2017/Dockerfile
+++ b/mssql/2017/Dockerfile
@@ -13,12 +13,14 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     apt-get install apt-transport-https && \
     curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - && \
     curl https://packages.microsoft.com/config/ubuntu/16.04/mssql-server-2017.list | tee /etc/apt/sources.list.d/mssql-server.list && \
-    apt-get update
+    rm -rf /var/lib/apt/lists/*
 
 # Install SQL Server which a prerequisite for the optional packages below.
 # Install full text search addons
 RUN export DEBIAN_FRONTEND=noninteractive && \
-    apt-get install -y mssql-server mssql-server-ha mssql-server-fts
+    apt-get update && \
+    apt-get install -y mssql-server mssql-server-ha mssql-server-fts && \
+    rm -rf /var/lib/apt/lists/*
 
 # we need en_US locales for MSSQL connection to work
 RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
@@ -33,7 +35,8 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - && \
     curl https://packages.microsoft.com/config/ubuntu/16.04/prod.list | tee /etc/apt/sources.list.d/msprod.list && \
     apt-get update && \
-    ACCEPT_EULA=Y apt-get install -y msodbcsql mssql-tools unixodbc-dev
+    ACCEPT_EULA=Y apt-get install -y msodbcsql mssql-tools unixodbc-dev && \
+    rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /custom
 COPY custom /custom/
diff --git a/mssql/2019/Dockerfile b/mssql/2019/Dockerfile
index 78e7180d..29693fdd 100644
--- a/mssql/2019/Dockerfile
+++ b/mssql/2019/Dockerfile
@@ -17,7 +17,8 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     curl https://packages.microsoft.com/config/ubuntu/16.04/mssql-server-2019.list | tee /etc/apt/sources.list.d/mssql-server.list && \
     apt-get update && \
     export DEBIAN_FRONTEND=noninteractive && \
-    apt-get install -y mssql-server mssql-server-ha mssql-server-fts
+    apt-get install -y mssql-server mssql-server-ha mssql-server-fts && \
+    rm -rf /var/lib/apt/lists/*
 
 # we need en_US locales for MSSQL connection to work
 RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
@@ -32,7 +33,8 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
     curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - && \
     curl https://packages.microsoft.com/config/ubuntu/16.04/prod.list | tee /etc/apt/sources.list.d/msprod.list && \
     apt-get update && \
-    ACCEPT_EULA=Y apt-get install -y msodbcsql mssql-tools unixodbc-dev
+    ACCEPT_EULA=Y apt-get install -y msodbcsql mssql-tools unixodbc-dev && \
+    rm -rf /var/lib/apt/lists/*
 
 RUN mkdir /custom
 COPY custom /custom/
diff --git a/nginx/Dockerfile b/nginx/Dockerfile
index b74cead6..3f5853e7 100644
--- a/nginx/Dockerfile
+++ b/nginx/Dockerfile
@@ -1,8 +1,8 @@
-FROM nginx:1.20
+FROM nginx:1.20-alpine
 
 ENV REMOTE_DATA=${REMOTE_DATA}
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
+RUN apk add --no-cache --update \
     nano \
     openssl \
     gettext
diff --git a/nginx/entrypoint.sh b/nginx/entrypoint.sh
index e970557f..c9497fd9 100644
--- a/nginx/entrypoint.sh
+++ b/nginx/entrypoint.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 # if there's no ssl certificate yet create it
 if [ ! -f "/etc/nginx/ssl/domain.crt" ]
diff --git a/php/php80/Dockerfile b/php/php80/Dockerfile
index f75410dd..5665b13f 100644
--- a/php/php80/Dockerfile
+++ b/php/php80/Dockerfile
@@ -1,36 +1,56 @@
-FROM php:8.0-fpm-bullseye
+FROM php:8.0-fpm-alpine
 
+ARG TARGETARCH
 ARG TIME_ZONE=Pacific/Auckland
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-        apt-transport-https \
-        libfreetype6-dev \
-        libjpeg62-turbo-dev \
-        libmcrypt-dev \
-        libpng-dev \
-        libxml2-dev \
-        libicu-dev \
-        libpq-dev \
-        gnupg2 \
+RUN apk add --no-cache --update \
+        linux-headers \
+        aspell \
+        autoconf \
+        bash \
+        bc \
+        curl \
+        icu \
+        icu-data-full \
+        freetds \
+        freetype \
+        ghostscript \
+        git \
+        gnupg \
+        graphviz \
+        libldap \
+        libjpeg \
+        libmcrypt \
+        libmemcached \
+        libpng \
+        libpq \
+        musl \
+        musl-utils \
+        musl-locales \
+        musl-locales-lang \
         nano \
-        vim \
-        wget \
         openssl \
-        locales \
         tzdata \
-        git \
+        vim \
+        wget \
+        zip
+
+RUN apk add --no-cache --update --virtual build-dependencies \
+        curl-dev \
+        freetype-dev \
+        freetds-dev \
+        libjpeg-turbo-dev \
+        libmcrypt-dev \
+        libpng-dev \
+        libpq-dev \
+        libxml2-dev \
         libzip-dev \
-        libmemcached-dev \
-        zip \
-        netcat \
-        bc \
-        ghostscript \
-        graphviz \
-        aspell \
-        libldap2-dev \
-        libltdl-dev \
-    && docker-php-ext-install -j$(nproc) \
-        zip \
+        icu-dev \
+        openldap-dev \
+        gcc \
+        make \
+        g++ && \
+    docker-php-ext-install -j$(nproc) zip \
         intl \
         soap \
         opcache \
@@ -40,69 +60,80 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
         mysqli \
         exif \
         ldap \
-    && docker-php-ext-configure gd \
+        pdo_dblib && \
+    docker-php-ext-configure gd \
             --with-freetype \
-            --with-jpeg \
-    && docker-php-ext-install -j$(nproc) gd
-
-RUN git clone https://github.com/tideways/php-profiler-extension.git \
-    && cd php-profiler-extension \
-    && phpize \
-    && ./configure \
-    && make && make install
+            --with-jpeg && \
+    docker-php-ext-install -j$(nproc) gd && \
+    apk del build-dependencies
+
+RUN apk add --no-cache --update --virtual build-dependencies \
+        gcc \
+        make \
+        g++ \
+        libmemcached-dev \
+        libzip-dev \
+        pkgconfig && \
+    git clone https://github.com/tideways/php-profiler-extension.git && \
+    cd php-profiler-extension && \
+    phpize && \
+    ./configure && \
+    make && make install && \
+    pecl install -o -f redis && \
+    pecl install -o -f igbinary && \
+    pecl install -o -f memcached && \
+    rm -rf /tmp/pear && \
+    apk del build-dependencies
 
 RUN echo "extension=tideways_xhprof.so" >> /usr/local/etc/php/conf.d/tideways_xhprof.ini
 
-RUN pecl install -o -f redis \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable redis
-
-RUN pecl install -o -f igbinary \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable igbinary
-
-RUN pecl install -o -f memcached \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable memcached
-
-# we need en_US locales for MSSQL connection to work
-# we need en_AU locales for behat to work
-RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
-    sed -i -e 's/# en_AU.UTF-8 UTF-8/en_AU.UTF-8 UTF-8/' /etc/locale.gen && \
-    dpkg-reconfigure --frontend=noninteractive locales && \
-    update-locale LANG=en_US.UTF-8
+RUN docker-php-ext-enable redis && \
+    docker-php-ext-enable igbinary && \
+    docker-php-ext-enable memcached
 
 ENV LANG en_US.UTF-8
 ENV LANGUAGE en_US.UTF-8
 ENV LC_ALL en_US.UTF-8
 
-# install mssql extension
-RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
-    && curl https://packages.microsoft.com/config/debian/11/prod.list > /etc/apt/sources.list.d/mssql-release.list \
-    && apt-get update && ACCEPT_EULA=Y apt-get install -y \
-    msodbcsql18 \
-    mssql-tools18 \
-    unixodbc-dev
+# Taken from https://learn.microsoft.com/en-us/sql/connect/odbc/linux-mac/installing-the-microsoft-odbc-driver-for-sql-server
+RUN curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
+
+#(Optional) Verify signature, if 'gpg' is missing install it using 'apk add gnupg':
+RUN curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/msodbcsql18_18.3.1.1-1_$TARGETARCH.sig && \
+    curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/mssql-tools18_18.3.1.1-1_$TARGETARCH.sig
+
+RUN curl https://packages.microsoft.com/keys/microsoft.asc  | gpg --import - && \
+    gpg --verify msodbcsql18_18.3.1.1-1_$TARGETARCH.sig msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    gpg --verify mssql-tools18_18.3.1.1-1_$TARGETARCH.sig mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
+
+# Install the package(s)
+RUN apk add --allow-untrusted msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    apk add --allow-untrusted mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
 
-RUN echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bash_profile \
-    && echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bashrc
+RUN echo 'export PATH="$PATH:/opt/mssql-tools18/bin"' >> ~/.bash_profile && \
+    echo 'export PATH="$PATH:/opt/mssql-tools18/bin"' >> ~/.bashrc
 
-# Workaround applied: https://github.com/microsoft/msphpsql/issues/1438#issuecomment-1444773949
-RUN pear config-set php_ini `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"` system \
-    && pecl install sqlsrv-5.10.1 pdo_sqlsrv-5.10.1 || \
-    apt-get install -y --allow-downgrades odbcinst=2.3.7 odbcinst1debian2=2.3.7 unixodbc=2.3.7 unixodbc-dev=2.3.7 && \
-    pecl install sqlsrv-5.10.1 pdo_sqlsrv-5.10.1
+RUN apk add --no-cache --update --virtual build-dependencies \
+      gcc \
+      make \
+      g++ \
+      unixodbc-dev && \
+    pear config-set php_ini `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"` system && \
+    pecl install sqlsrv && \
+    pecl install pdo_sqlsrv && \
+    rm -rf /tmp/pear && \
+    apk del build-dependencies
 
 RUN docker-php-ext-enable sqlsrv.so && docker-php-ext-enable pdo_sqlsrv.so
 
-RUN ln -fs /usr/share/zoneinfo/${TIME_ZONE} /etc/localtime \
-    && dpkg-reconfigure --frontend noninteractive tzdata
+RUN ln -fs /usr/share/zoneinfo/${TIME_ZONE} /etc/localtime
 
-# Python 3.7 for ML Recommender.
-RUN apt-get update && apt install -y python3 \
-    python3-pip \
-    python3-wheel \
-    python3-venv \
+# Python 3 for ML Recommender.
+RUN apk add --no-cache --update python3 \
+    py3-pip \
+    py3-wheel \
+    py3-virtualenv \
     python3-dev
 
 COPY config/php.ini /usr/local/etc/php/
@@ -112,7 +143,7 @@ COPY config/fpm.conf /usr/local/etc/php-fpm.d/zz-totara.conf
 RUN echo 'for f in ~/custom_shell/*.sh; do [[ -e "$f" ]] && source "$f"; done;' >> ~/.bashrc
 
 # Have the option of using the oh my zsh shell.
-RUN apt-get update && apt-get install -y zsh
+RUN apk add --no-cache --update zsh
 RUN sh -c "$(curl https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)" --unattended
 RUN git clone https://github.com/romkatv/powerlevel10k ~/.oh-my-zsh/custom/themes/powerlevel10k
 RUN git clone https://github.com/zsh-users/zsh-autosuggestions ~/.oh-my-zsh/custom/plugins/zsh-autosuggestions
diff --git a/php/php81/Dockerfile b/php/php81/Dockerfile
index 8a25a94e..92ff5bb4 100644
--- a/php/php81/Dockerfile
+++ b/php/php81/Dockerfile
@@ -1,36 +1,56 @@
-FROM php:8.1-fpm-bullseye
+FROM php:8.1-fpm-alpine
 
+ARG TARGETARCH
 ARG TIME_ZONE=Pacific/Auckland
 
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
-        apt-transport-https \
-        libfreetype6-dev \
-        libjpeg62-turbo-dev \
-        libmcrypt-dev \
-        libpng-dev \
-        libxml2-dev \
-        libicu-dev \
-        libpq-dev \
-        gnupg2 \
+RUN apk add --no-cache --update \
+        linux-headers \
+        aspell \
+        autoconf \
+        bash \
+        bc \
+        curl \
+        icu \
+        icu-data-full \
+        freetds \
+        freetype \
+        ghostscript \
+        git \
+        gnupg \
+        graphviz \
+        libldap \
+        libjpeg \
+        libmcrypt \
+        libmemcached \
+        libpng \
+        libpq \
+        musl \
+        musl-utils \
+        musl-locales \
+        musl-locales-lang \
         nano \
-        vim \
-        wget \
         openssl \
-        locales \
         tzdata \
-        git \
+        vim \
+        wget \
+        zip
+
+RUN apk add --no-cache --update --virtual build-dependencies \
+        curl-dev \
+        freetype-dev \
+        freetds-dev \
+        libjpeg-turbo-dev \
+        libmcrypt-dev \
+        libpng-dev \
+        libpq-dev \
+        libxml2-dev \
         libzip-dev \
-        libmemcached-dev \
-        zip \
-        netcat \
-        bc \
-        ghostscript \
-        graphviz \
-        aspell \
-        libldap2-dev \
-        libltdl-dev \
-    && docker-php-ext-install -j$(nproc) \
-        zip \
+        icu-dev \
+        openldap-dev \
+        gcc \
+        make \
+        g++ && \
+    docker-php-ext-install -j$(nproc) zip \
         intl \
         soap \
         opcache \
@@ -40,69 +60,80 @@ RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y \
         mysqli \
         exif \
         ldap \
-    && docker-php-ext-configure gd \
+        pdo_dblib && \
+    docker-php-ext-configure gd \
             --with-freetype \
-            --with-jpeg \
-    && docker-php-ext-install -j$(nproc) gd
-
-RUN git clone https://github.com/tideways/php-profiler-extension.git \
-    && cd php-profiler-extension \
-    && phpize \
-    && ./configure \
-    && make && make install
+            --with-jpeg && \
+    docker-php-ext-install -j$(nproc) gd && \
+    apk del build-dependencies
+
+RUN apk add --no-cache --update --virtual build-dependencies \
+        gcc \
+        make \
+        g++ \
+        libmemcached-dev \
+        libzip-dev \
+        pkgconfig && \
+    git clone https://github.com/tideways/php-profiler-extension.git && \
+    cd php-profiler-extension && \
+    phpize && \
+    ./configure && \
+    make && make install && \
+    pecl install -o -f redis && \
+    pecl install -o -f igbinary && \
+    pecl install -o -f memcached && \
+    rm -rf /tmp/pear && \
+    apk del build-dependencies
 
 RUN echo "extension=tideways_xhprof.so" >> /usr/local/etc/php/conf.d/tideways_xhprof.ini
 
-RUN pecl install -o -f redis \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable redis
-
-RUN pecl install -o -f igbinary \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable igbinary
-
-RUN pecl install -o -f memcached \
-    &&  rm -rf /tmp/pear \
-    &&  docker-php-ext-enable memcached
-
-# we need en_US locales for MSSQL connection to work
-# we need en_AU locales for behat to work
-RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && \
-    sed -i -e 's/# en_AU.UTF-8 UTF-8/en_AU.UTF-8 UTF-8/' /etc/locale.gen && \
-    dpkg-reconfigure --frontend=noninteractive locales && \
-    update-locale LANG=en_US.UTF-8
+RUN docker-php-ext-enable redis && \
+    docker-php-ext-enable igbinary && \
+    docker-php-ext-enable memcached
 
 ENV LANG en_US.UTF-8
 ENV LANGUAGE en_US.UTF-8
 ENV LC_ALL en_US.UTF-8
 
-# install mssql extension
-RUN curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add - \
-    && curl https://packages.microsoft.com/config/debian/11/prod.list > /etc/apt/sources.list.d/mssql-release.list \
-    && apt-get update && ACCEPT_EULA=Y apt-get install -y \
-    msodbcsql18 \
-    mssql-tools18 \
-    unixodbc-dev
+# Taken from https://learn.microsoft.com/en-us/sql/connect/odbc/linux-mac/installing-the-microsoft-odbc-driver-for-sql-server
+RUN curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
+
+#(Optional) Verify signature, if 'gpg' is missing install it using 'apk add gnupg':
+RUN curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/msodbcsql18_18.3.1.1-1_$TARGETARCH.sig && \
+    curl -O https://download.microsoft.com/download/3/5/5/355d7943-a338-41a7-858d-53b259ea33f5/mssql-tools18_18.3.1.1-1_$TARGETARCH.sig
+
+RUN curl https://packages.microsoft.com/keys/microsoft.asc  | gpg --import - && \
+    gpg --verify msodbcsql18_18.3.1.1-1_$TARGETARCH.sig msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    gpg --verify mssql-tools18_18.3.1.1-1_$TARGETARCH.sig mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
+
+# Install the package(s)
+RUN apk add --allow-untrusted msodbcsql18_18.3.1.1-1_$TARGETARCH.apk && \
+    apk add --allow-untrusted mssql-tools18_18.3.1.1-1_$TARGETARCH.apk
 
-RUN echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bash_profile \
-    && echo 'export PATH="$PATH:/opt/mssql-tools/bin"' >> ~/.bashrc
+RUN echo 'export PATH="$PATH:/opt/mssql-tools18/bin"' >> ~/.bash_profile && \
+    echo 'export PATH="$PATH:/opt/mssql-tools18/bin"' >> ~/.bashrc
 
-# Workaround applied: https://github.com/microsoft/msphpsql/issues/1438#issuecomment-1444773949
-RUN pear config-set php_ini `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"` system \
-    && pecl install sqlsrv-5.10.1 pdo_sqlsrv-5.10.1 || \
-    apt-get install -y --allow-downgrades odbcinst=2.3.7 odbcinst1debian2=2.3.7 unixodbc=2.3.7 unixodbc-dev=2.3.7 && \
-    pecl install sqlsrv-5.10.1 pdo_sqlsrv-5.10.1
+RUN apk add --no-cache --update --virtual build-dependencies \
+      gcc \
+      make \
+      g++ \
+      unixodbc-dev && \
+    pear config-set php_ini `php --ini | grep "Loaded Configuration" | sed -e "s|.*:\s*||"` system && \
+    pecl install sqlsrv && \
+    pecl install pdo_sqlsrv && \
+    rm -rf /tmp/pear && \
+    apk del build-dependencies
 
 RUN docker-php-ext-enable sqlsrv.so && docker-php-ext-enable pdo_sqlsrv.so
 
-RUN ln -fs /usr/share/zoneinfo/${TIME_ZONE} /etc/localtime \
-    && dpkg-reconfigure --frontend noninteractive tzdata
+RUN ln -fs /usr/share/zoneinfo/${TIME_ZONE} /etc/localtime
 
-# Python 3.7 for ML Recommender.
-RUN apt-get update && apt install -y python3 \
-    python3-pip \
-    python3-wheel \
-    python3-venv \
+# Python 3 for ML Recommender.
+RUN apk add --no-cache --update python3 \
+    py3-pip \
+    py3-wheel \
+    py3-virtualenv \
     python3-dev
 
 COPY config/php.ini /usr/local/etc/php/
@@ -112,7 +143,7 @@ COPY config/fpm.conf /usr/local/etc/php-fpm.d/zz-totara.conf
 RUN echo 'for f in ~/custom_shell/*.sh; do [[ -e "$f" ]] && source "$f"; done;' >> ~/.bashrc
 
 # Have the option of using the oh my zsh shell.
-RUN apt-get update && apt-get install -y zsh
+RUN apk add --no-cache --update zsh
 RUN sh -c "$(curl https://raw.githubusercontent.com/robbyrussell/oh-my-zsh/master/tools/install.sh)" --unattended
 RUN git clone https://github.com/romkatv/powerlevel10k ~/.oh-my-zsh/custom/themes/powerlevel10k
 RUN git clone https://github.com/zsh-users/zsh-autosuggestions ~/.oh-my-zsh/custom/plugins/zsh-autosuggestions
diff --git a/shell/.zshrc b/shell/.zshrc
index 73edf339..31029705 100644
--- a/shell/.zshrc
+++ b/shell/.zshrc
@@ -54,7 +54,7 @@ POWERLEVEL9K_CUSTOM_TOTARA_FOREGROUND="black"
 zsh_dir_name(){
     local diricon='\uf07c'
     local dirfull=$(pwd)
-    local dir=$(echo "$dirfull" | grep -oP "^/var/www/totara/\K.*")
+    local dir="${dirfull/\/var\/www\/totara\//"$"}"
     if [[ -z "$dir" ]]; then
         dir="$dirfull";
     fi