feat: drop python version selection and force python3

Dockerfile

@@ -4,18 +4,17 @@ ENV LANG C.UTF-8
 RUN mkdir -p /usr/share/man/man1 && mkdir -p /usr/share/man/man7
 RUN apt-get update && apt-get -y dist-upgrade \
     && rm -rf /var/lib/apt/lists/*
-ARG PYTHON
 RUN apt-get update && apt-get -y --no-install-recommends install \
     gettext \
     uwsgi \
-    uwsgi-plugin-$PYTHON \
+    uwsgi-plugin-python3 \
     graphviz \
     postgresql-client \
-    $PYTHON-pip \
-    $PYTHON-setuptools \
+    python3-pip \
+    python3-setuptools \
     pwgen \
     && rm -rf /var/lib/apt/lists/*
-RUN test $PYTHON = "python" && export py=python2 pip=pip2 || export py=python3 pip=pip3; \
+RUN export py=python3 pip=pip3; \
     update-alternatives --install /usr/bin/python python /usr/bin/$py 50 && \
     update-alternatives --install /usr/bin/pip pip /usr/bin/$pip 50 && \
     pip install --upgrade pip
@@ -27,7 +26,6 @@ ENV PIP_DISABLE_PIP_VERSION_CHECK on
 RUN useradd cubicweb --uid 1000 -m -s /bin/bash
 RUN install -d -o cubicweb -g cubicweb /etc/cubicweb.d
 COPY uwsgi.ini /etc/uwsgi/uwsgi.ini
-RUN echo "plugins = http,$PYTHON" >> /etc/uwsgi/uwsgi.ini
 COPY pyramid.ini.j2 /
 COPY entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh

build.py

@@ -156,7 +156,6 @@ def build_image(image: CubicWebImage, onbuild: Optional[str], no_cache=False) ->
         args["FROM"] = image.tag
         tag = image.tag + "-onbuild"
     else:
-        args["PYTHON"] = "python3"
         dockerfile = "Dockerfile"
         args["DIST"] = image.debian_dist
         args["CUBICWEB_SOURCE"] = f"cubicweb[pyramid]=={image.cubicweb_version}"

uwsgi.ini

@@ -9,3 +9,4 @@ lazy-apps = true
 log-master = true
 disable-logging = true
 http-timeout = 180
+plugins = http,python3