Simplified container build

Containerfile

@@ -6,7 +6,7 @@ FROM alpine:3.15
 WORKDIR /usr/src/app
 
 # Install run dependencies first
-RUN apk add --no-cache python3 tzdata
+RUN apk add --no-cache python3 py3-lxml tzdata
 
 # system pip could be removed after build, but apk then decides to also remove all its
 # python dependencies, even if they are explicitly installed as python packages
@@ -15,16 +15,7 @@ RUN \
 	apk add py3-pip && \
 	pip install wheel
 
-# these are more static than the real requirements, which means caching
-COPY ./requirements_pre.txt ./requirements_pre.txt
 
-RUN \
-	apk add --no-cache --virtual .build-deps gcc g++ python3-dev libxml2-dev libxslt-dev libffi-dev libc-dev py3-pip linux-headers && \
-	pip install --no-cache-dir -r requirements_pre.txt && \
-	apk del .build-deps
-
-
-# less likely to be cached
 COPY ./requirements.txt ./requirements.txt
 
 RUN \
@@ -39,10 +30,9 @@ COPY . .
 
 RUN pip install /usr/src/app
 
-# Docker-specific configuration
-# defaulting to IPv4 is no longer necessary (default host is dual stack)
+# Docker-specific configuration and default to IPv4
 ENV MALOJA_SKIP_SETUP=yes
-ENV PYTHONUNBUFFERED=1
+ENV MALOJA_HOST=0.0.0.0
 
 EXPOSE 42010
 # use exec form for better signal handling https://docs.docker.com/engine/reference/builder/#entrypoint