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{{tag>docker nginx proxy}}

====== Write to custom host path from Docker container ======
Say you have an app that generates some reports and its running in its own container. You want to serve the reports from this container via nginx on host machine.

In your Dockerfile create //reports// dir and user/group, example of Dockerfile utilizing [[https://github.com/aptible/supercronic|supercronic]] to run some cronjob.

<code Dockerfile>
FROM python:3.10-alpine3.16
RUN apk add --no-cache libffi-dev build-base cmake openssl-dev curl tzdata gnupg unixodbc-dev
RUN apk add --no-cache libffi-dev build-base cmake openssl-dev curl tzdata gnupg unixodbc-dev

ENV SUPERCRONIC_URL=https://github.com/aptible/supercronic/releases/download/v0.2.1/supercronic-linux-amd64 \
    SUPERCRONIC=supercronic-linux-amd64 \
    SUPERCRONIC_SHA1SUM=d7f4c0886eb85249ad05ed592902fa6865bb9d70

RUN curl -fsSLO "$SUPERCRONIC_URL" \
 && echo "${SUPERCRONIC_SHA1SUM}  ${SUPERCRONIC}" | sha1sum -c - \
 && chmod +x "$SUPERCRONIC" \
 && mv "$SUPERCRONIC" "/usr/local/bin/${SUPERCRONIC}" \
 && ln -s "/usr/local/bin/${SUPERCRONIC}" /usr/local/bin/supercronic

RUN addgroup --gid 2222 --system user_app && adduser --disabled-password --uid 2222 --system user_app --ingroup user_app
WORKDIR /app
RUN mkdir -p /app/exports
RUN mkdir -p /app/exports/public
RUN chown -R user_app:user_app /app/exports

COPY . .

USER user_app
CMD ["supercronic", "/app/python-docker-crontab"]

</code>


This user should exist on the host machine with some UID e.g.:
  useradd --no-create-home --uid 2222 user_app

In nginx setup a location on the host to serve e.g.

<code nginx>
location /reports/ {
        autoindex on;
        autoindex_localtime on;
        alias /var/www/app_reports/public/;
    }

</code>

The host path ///var/www/app_reports/public/// needs to be mounted in container, similar to a volume, and needs to have the owner set to ''user_app'' so that the containerized app can write to it and nginx can serve it. Permissions can be ''0755'', so owner (user_app) can read/write/execute.
  useradd --no-create-home --uid 2222 user_app
  chown -R user_app:user_app /var/www/app_reports
  

Build and run the docker container:
  docker build -t python-reports .
  docker run --name reports -d -v /var/www/app_reports/:/app/exports/ python-reports
====== Tested on ======
  * Debian 11
  * Docker 20.10.21

====== See also ======
  * [[wiki:use_hetzner_storage_box_docker_volume|Use Hetzner storage box as docker volume]]
====== References ======