How to run the container with a non root user?

[cairoapcampos]

I'm trying to create a GestióIP container run by a non-root user. I still haven't been successful in creating this container.

I wanted to know how to create a container in the best way. Could you give me a hint on how to do this?

[cairoapcampos]

#My dockerfile:

FROM gestioip/gestioip:3570

# Create the user in a group of the same name and associate the application directory.
RUN groupadd -g 1001 myuser && useradd -r -m -u 1001 -g myuser myuser

RUN chown -R myuser:myuser /var/www/html
RUN chmod 755 -R /var/www/html

USER myuser

#Logs:

gip          | usermod: Permission denied.
gip          | usermod: cannot lock /etc/passwd; try again later.
gip          | /bin/sed: couldn't open temporary file /etc/xinetd.d/sedE4Jhnd: Permission denied
gip          |  * Stopping internet superserver xinetd
gip          |    ...done.
gip          |  * Starting internet superserver xinetd
gip          |    ...done.
gip          | System has not been booted with systemd as init system (PID 1). Can't operate.
gip          | Failed to connect to bus: Host is down
gip          | Synchronizing state of vsftpd.service with SysV service script with /lib/systemd/systemd-sysv-install.
gip          | Executing: /lib/systemd/systemd-sysv-install disable vsftpd
gip          | update-rc.d: error: Permission denied
gip          | chown: changing ownership of '/usr/share/gestioip/etc/apache/apache-groups': Operation not permitted
gip          | chown: changing ownership of '/usr/share/gestioip/etc/apache/users-gestioip': Operation not permitted
gip          | chown: changing ownership of '/usr/share/gestioip/etc/apache/apache_ldap_require.conf': Operation not permitted
gip          | chown: changing ownership of '/usr/share/gestioip/etc/apache/apache_ldap.conf': Operation not permitted
gip          | chown: changing ownership of '/usr/share/gestioip/etc/apache': Operation not permitted
gip          | touch: cannot touch '.initialized': Permission denied
gip          |  * Starting enhanced syslogd rsyslogd
gip          | mknod: /dev/xconsole: Permission denied
gip          | chown: cannot access '/dev/xconsole': No such file or directory
gip          | rsyslogd: error writing pid file (creation stage)
gip          | : Permission denied
gip          | rsyslogd: run failed with error -3000 (see rsyslog.h or try https://www.rsyslog.com/e/3000 to learn what that number means)
gip          | rsyslog startup failure: error reading "fork pipe": No such process
gip          |    ...done.
gip          |  * Starting periodic command scheduler cron
gip          | cron: can't open or create /var/run/crond.pid: Permission denied
gip          |    ...fail!
gip          | AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.20.0.2. Set the 'ServerName' directive globally to suppress this message
gip          | (13)Permission denied: AH00091: apache2: could not open error log file /var/log/apache2/error.log.
gip          | AH00015: Unable to open logs
gip          | Action '-D FOREGROUND' failed.
gip          | The Apache error log may have more information.
gip          | usermod: Permission denied.
gip          | usermod: cannot lock /etc/passwd; try again later.