Changed user with useradd and good pid

Dockerfile

@@ -6,8 +6,8 @@ ENV DEBIAN_FRONTEND noninteractive
 ENV HOME /root
 
 ARG PIWIGO_VERSION="13.2.0"
-ARG PIWIGO_USER="www-data"
-ARG PIWIGO_GROUP="www-data"
+ARG PIWIGO_USER_ID=53
+ARG PIWIGO_GROUP_ID=53
 
 RUN apt update -y \
      && apt install -yy \
@@ -28,6 +28,8 @@ RUN apt update -y \
             exiftool \
      && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
+RUN useradd -u $PIWIGO_USER -g $PIWIGO_GROUP user
+
 RUN wget -q -O piwigo.zip http://piwigo.org/download/dlcounter.php?code=$PIWIGO_VERSION && \
     unzip piwigo.zip && \
     rm /var/www/* -rf && \
@@ -44,9 +46,9 @@ RUN wget -q -O piwigo.zip http://piwigo.org/download/dlcounter.php?code=$PIWIGO_
     sed -i "s/memory_limit = 128M/memory_limit = 512M/" /etc/php/7.4/apache2/php.ini &&\
     sed -i "s/max_input_time = 60/max_input_time = 180/" /etc/php/7.4/apache2/php.ini &&\
     sed -i "s/post_max_size = 8M/post_max_size = 100M/" /etc/php/7.4/apache2/php.ini &&\
-    sed -i "s/upload_max_filesize = 2M/upload_max_filesize = 100M/" /etc/php/7.4/apache2/php.ini
-    sed -i "s/APACHE_RUN_USER=www-data/APACHE_RUN_USER=$PIWIGO_USER/" /etc/apache2/envvars
-    sed -i "s/APACHE_RUN_GROUP=www-data/APACHE_RUN_GROUP=$PIWIGO_GROUP/" /etc/apache2/envvars
+    sed -i "s/upload_max_filesize = 2M/upload_max_filesize = 100M/" /etc/php/7.4/apache2/php.ini  &&\
+    sed -i "s/APACHE_RUN_USER=www-data/APACHE_RUN_USER=user/" /etc/apache2/envvars  &&\
+    sed -i "s/APACHE_RUN_GROUP=www-data/APACHE_RUN_GROUP=user/" /etc/apache2/envvars
 
 
 VOLUME ["/var/www/galleries", "/var/www/themes", "/var/www/plugins", "/var/www/local", "/var/www/_data/i", "/config"]