Add FLATNOTES_PORT envvar to Dockerfile.experimental

Dockerfile.experimental

@@ -40,6 +40,7 @@ ARG BUILD_DIR
 ENV PUID=1000
 ENV PGID=1000
 ENV EXEC_TOOL=su-exec
+ENV FLATNOTES_PORT=8080
 
 ENV APP_PATH=/app
 ENV FLATNOTES_PATH=/data
@@ -55,10 +56,11 @@ COPY server ./server
 COPY --from=build ${BUILD_DIR}/client/dist ./client/dist
 COPY --from=pipenv-build ${APP_PATH}/.venv/lib/python3.11/site-packages/ /usr/local/lib/python3.11/site-packages/
 
+COPY entrypoint.sh healthcheck.sh /
+RUN chmod +x /entrypoint.sh /healthcheck.sh
+
 VOLUME /data
-EXPOSE 8080/tcp
-HEALTHCHECK --interval=60s --timeout=10s CMD curl -f http://localhost:8080/health || exit 1
+EXPOSE ${FLATNOTES_PORT}/tcp
+HEALTHCHECK --interval=60s --timeout=10s CMD /healthcheck.sh
 
-COPY entrypoint.sh /
-RUN chmod +x /entrypoint.sh
 ENTRYPOINT [ "/entrypoint.sh" ]