Update host mount directory creation

Add a HOST_MOUNT argument to the Dockerfile to support adjusting the
path for the host mount directory in the image. Rearrange some of the
RUN instructions in the Dockerfile and change the host mount directory
creation to also create any intermediate directories.

Dockerfile

@@ -69,8 +69,13 @@ ARG CISA_GID=${CISA_UID}
 ARG CISA_USER="cisa"
 ENV CISA_GROUP=${CISA_USER}
 ENV CISA_HOME="/home/${CISA_USER}"
+
+# Python virtual environment location
 ENV VIRTUAL_ENV="${CISA_HOME}/.venv"
 
+# Host mount directory
+ARG HOST_MOUNT="${CISA_HOME}/host_mount"
+
 RUN apk --no-cache add \
   ca-certificates=20220614-r4 \
   chromium=112.0.5615.49-r0 \
@@ -81,19 +86,20 @@ RUN apk --no-cache add \
 RUN addgroup --system --gid ${CISA_GID} ${CISA_GROUP} \
   && adduser --system --uid ${CISA_UID} --ingroup ${CISA_GROUP} ${CISA_USER}
 
+# Create the HOST MOUNT directory (and any intermediate directories)
+RUN mkdir --parents ${HOST_MOUNT}
+
 # Copy in the Python venv we created in the compile stage and re-symlink
 # python3 in the venv to the Python binary in this image
 COPY --from=compile-stage --chown=${CISA_USER}:${CISA_GROUP} ${VIRTUAL_ENV} ${VIRTUAL_ENV}/
 RUN ln -sf "$(command -v python3)" "${VIRTUAL_ENV}"/bin/python3
 ENV PATH="${VIRTUAL_ENV}/bin:$PATH"
 
-WORKDIR ${CISA_HOME}
-RUN mkdir host_mount
-
 # Copy in the necessary files
-COPY --chown=${CISA_USER}:${CISA_GROUP} src/version.txt src/vdp_scanner.py ./
+COPY --chown=${CISA_USER}:${CISA_GROUP} src/version.txt src/vdp_scanner.py ${CISA_HOME}/
 
 # Prepare to run
+WORKDIR ${CISA_HOME}
 USER ${CISA_USER}:${CISA_GROUP}
 ENTRYPOINT ["python3", "vdp_scanner.py"]
 CMD ["github"]