How to run only one thing as root in docker - symfony

Question

I'm trying to create a Dockerfile which runs as non-root user.
When i building this all works fine, but nginx cannot write the log file because it dosen't have enough permissions. Can I, when building a Docker, give root permissions only for nginx?
I'm trying chmod, chown for blocked directories. Doesn't work
FROM php:7.1-fpm-alpine
RUN apk add --no-cache shadow
RUN apk add --no-cache --virtual .ext-deps \
openssl \
unzip \
libjpeg-turbo-dev \
libwebp-dev \
libpng-dev \
freetype-dev \
libmcrypt-dev \
imagemagick-dev \
nodejs-npm \
nginx \
git \
inkscape
# imagick
RUN apk add --update --no-cache autoconf g++ imagemagick-dev libtool make pcre-dev \
&& pecl install imagick \
&& docker-php-ext-enable imagick \
&& apk del autoconf g++ libtool make pcre-dev
# Install Blackfire
RUN version=$(php -r "echo PHP_MAJOR_VERSION.PHP_MINOR_VERSION;") \
&& curl -A "Docker" -o /tmp/blackfire-probe.tar.gz -D - -L -s https://blackfire.io/api/v1/releases/probe/php/linux/amd64/$version \
&& tar zxpf /tmp/blackfire-probe.tar.gz -C /tmp \
&& mv /tmp/blackfire-*.so $(php -r "echo ini_get('extension_dir');")/blackfire.so \
&& printf "extension=blackfire.so\nblackfire.agent_socket=tcp://blackfire:8707\n" > $PHP_INI_DIR/conf.d/blackfire.ini
RUN apk add -y icu-dev \
&& docker-php-ext-configure intl \
&& docker-php-ext-install intl
RUN docker-php-ext-configure pdo_mysql && \
docker-php-ext-configure opcache && \
docker-php-ext-configure exif && \
docker-php-ext-configure pdo && \
docker-php-ext-configure zip && \
docker-php-ext-configure gd \
--with-jpeg-dir=/usr/include --with-png-dir=/usr/include --with-webp-dir=/usr/include --with-freetype-dir=/usr/include && \
docker-php-ext-configure sockets && \
docker-php-ext-configure mcrypt
RUN docker-php-ext-install pdo zip pdo_mysql opcache exif gd sockets mcrypt && \
docker-php-source delete
RUN ln -s /usr/bin/php7 /usr/bin/php && \
curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer && \
mkdir -p /run/nginx
COPY ./init.sh /
COPY ./default.conf /etc/nginx/conf.d/default.conf
COPY ./.env /
RUN chmod +x /init.sh
EXPOSE 80
RUN addgroup -g 1001 node \
&& adduser -u 1001 -G node -s /bin/sh -D node
ARG UID=1001
ARG GID=1001
ENV UID=${UID}
ENV GID=${GID}
RUN usermod -u $UID node \
&& groupmod -g $GID node
RUN chown 1001:1001 /var/lib/nginx -R
RUN mkdir -p /var/tmp/nginx
RUN chown 1001:1001 /var/tmp/nginx -R
USER node
ENTRYPOINT [ "/init.sh" ]

Answer 1

There are quite a few unknowns in your question, for example, the contents of your default.conf file. By default the nginx logs are stored in /var/log/nginx, but I'll assume you're overriding that in the configuration.
The next thing is that the master process of nginx needs to be run as root if you wan't it to be able to bind to system ports (0 - 1023) so in case you are using nginx as a web server and intend to use ports 80 and 443 you should stick with running the nginx process as root.
In case you plan to use other ports and are set on the idea of running the master process as non-root, then you can check this answer for suggestions on how to do that - https://stackoverflow.com/a/42329561/5359953
I am using the term master process a lot here, because nginx spawns worker processes to handle the actual requests and those can be run as a different user (Defined in the nginx configuration file)

Answer 2

I found the solution. I just changed RUN chown 1001:1001 /var/lib/nginx -R to RUN chown -R 1001:1001 /var/. Thats works fine

Answer 3

RUN chown -R 1001:1001 /var/
sometimes it's will be actually bad decision.
u can try add permissions like this
RUN chown -R 1001:1001 /var/tmp/nginx
RUN chown -R 1001:1001 /var/lib/nginx
RUN chown -R 1001:1001 /var/log/nginx
RUN chown -R 1001:1001 /run/nginx
I guess RUN chown 1001:1001 /var/lib/nginx -R work wrong because I set the flag -R too late