MariaDB "MySQL server has gone away" during admin user creation with docker

Hi,
Im currently trying to install Nextcloud in my VM with docker(-compose). I use the example docker-compose file from the offical github repo changed to my needs. When I try to create the admin user I get the Error: Error while trying to create admin user: Failed to connect to the database: An exception occurred in driver: SQLSTATE[HY000] [2006] MySQL server has gone away
I already tried tips for when this happens with mariadb like changing innodb_log_file_size and max_allowed_packetbut that also didnt suceed.

Then I tried to connect to the mariadb server with the mysql cli this returns

 ERROR 1130 (HY000): Host '192.168.1.225' is not allowed to connect to this MariaDB server

But skip-networking and bind-adress are also not defined in my.cnf

Quite a few people seem to have this prolem. But I couldnt find a solution so far.



This is my docker-compose:

version: '3'

volumes:
  nextcloud:
  db:

services:
  nextcloud_mariadb:
    image: mariadb
    command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
    restart: always
    volumes:
      - /home/user/nextcloud/db:/var/lib/mysql
      - /home/user/nextcloud/my.cnf:/etc/mysql/my.cnf
    environment:
      - MYSQL_ROOT_PASSWORD='xxx'
      - MYSQL_PASSWORD='xxx'
      - MYSQL_DATABASE=nextcloud
      - MYSQL_USER=nextcloud
    ports:
      - 3306:3306
    networks:
      - nextcloud

  nextcloud:
    image: nextcloud:fpm-alpine
    links:
      - nextcloud_mariadb
    volumes:
      - /home/user/mnt/VM-Data/nextcloud:/var/www/html
    restart: always
    ports:
      -  9000:9000
    networks: 
      - nextcloud 
  nextcloud_nginx:
    image: nginx
    ports:
      - 8082:80
    links:
      - nextcloud
    volumes:
      - /home/user/nextcloud/nginx.conf:/etc/nginx/nginx.conf:ro
      - /home/user/mnt/VM-Data/nextcloud:/var/www/html:ro
    restart: always
    networks:
      - nextcloud

Is this the right way to import the my.cnf file? I was confused by the explanation here: https://hub.docker.com/_/mariadb/
Edit: I tried printing the my.cnf from the docker container and it indeed updated it. So that seems to work.

This is my my.cnf:

# MariaDB database server configuration file.
#
# You can copy this file to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port            = 3306
socket          = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket          = /var/run/mysqld/mysqld.sock
nice            = 0

[mysqld]
#
# * Basic Settings
#
#user           = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
lc_messages_dir = /usr/share/mysql
lc_messages     = en_US
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#bind-address         = 127.0.0.1
#
# * Fine Tuning
#
max_connections       = 100
connect_timeout       = 5
wait_timeout          = 6000
max_allowed_packet    = 128M
thread_cache_size       = 128
sort_buffer_size      = 4M
bulk_insert_buffer_size = 16M
tmp_table_size        = 32M
max_heap_table_size   = 32M
#
# * MyISAM
#
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched. On error, make copy and try a repair.
myisam_recover_options = BACKUP
key_buffer_size       = 128M
#open-files-limit     = 2000
table_open_cache      = 400
myisam_sort_buffer_size = 512M
concurrent_insert     = 2
read_buffer_size      = 2M
read_rnd_buffer_size  = 1M
#
# * Query Cache Configuration
#
# Cache only tiny result sets, so we can fit more in the query cache.
query_cache_limit       = 128K
query_cache_size        = 64M
# for more write intensive setups, set to DEMAND or OFF
#query_cache_type       = DEMAND
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
#
# we do want to know about network errors and such
#log_warnings         = 2
#
# Enable the slow query log to see queries with especially long duration
#slow_query_log[={0|1}]
slow_query_log_file   = /var/log/mysql/mariadb-slow.log
long_query_time = 10
#log_slow_rate_limit  = 1000
#log_slow_verbosity   = query_plan

#log-queries-not-using-indexes
#log_slow_admin_statements
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id            = 1
#report_host          = master1
#auto_increment_increment = 2
#auto_increment_offset  = 1
#log_bin                = /var/log/mysql/mariadb-bin
#log_bin_index        = /var/log/mysql/mariadb-bin.index
# not fab for performance, but safer
#sync_binlog          = 1
expire_logs_days      = 10
max_binlog_size         = 100M
# slaves
#relay_log            = /var/log/mysql/relay-bin
#relay_log_index      = /var/log/mysql/relay-bin.index
#relay_log_info_file  = /var/log/mysql/relay-bin.info
#log_slave_updates
#read_only
#
# If applications support it, this stricter sql_mode prevents some
# mistakes like inserting invalid dates etc.
#sql_mode             = NO_ENGINE_SUBSTITUTION,TRADITIONAL
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
default_storage_engine  = InnoDB
innodb_buffer_pool_size = 256M
innodb_log_buffer_size  = 128M
innodb_file_per_table = 1
innodb_open_files     = 400
innodb_io_capacity    = 400
innodb_flush_method   = O_DIRECT
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem

#
# * Galera-related settings
#
[galera]
# Mandatory settings# MariaDB database server configuration file.
#
# You can copy this file to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port            = 3306
socket          = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket          = /var/run/mysqld/mysqld.sock
nice            = 0

[mysqld]
#
# * Basic Settings
#
#user           = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /var/lib/mysql
tmpdir          = /tmp
lc_messages_dir = /usr/share/mysql
lc_messages     = en_US
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#bind-address         = 127.0.0.1
#
# * Fine Tuning
#
max_connections       = 100
connect_timeout       = 5
wait_timeout          = 6000
max_allowed_packet    = 128M
thread_cache_size       = 128
sort_buffer_size      = 4M
bulk_insert_buffer_size = 16M
tmp_table_size        = 32M
max_heap_table_size   = 32M
#
# * MyISAM
#
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched. On error, make copy and try a repair.
myisam_recover_options = BACKUP
key_buffer_size       = 128M
#open-files-limit     = 2000
table_open_cache      = 400
myisam_sort_buffer_size = 512M
concurrent_insert     = 2
read_buffer_size      = 2M
read_rnd_buffer_size  = 1M
#
# * Query Cache Configuration
#
# Cache only tiny result sets, so we can fit more in the query cache.
query_cache_limit       = 128K
query_cache_size        = 64M
# for more write intensive setups, set to DEMAND or OFF
#query_cache_type       = DEMAND
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
#
# we do want to know about network errors and such
#log_warnings         = 2
#
# Enable the slow query log to see queries with especially long duration
#slow_query_log[={0|1}]
slow_query_log_file   = /var/log/mysql/mariadb-slow.log
long_query_time = 10
#log_slow_rate_limit  = 1000
#log_slow_verbosity   = query_plan

#log-queries-not-using-indexes
#log_slow_admin_statements
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id            = 1
#report_host          = master1
#auto_increment_increment = 2
#auto_increment_offset  = 1
#log_bin                = /var/log/mysql/mariadb-bin
#log_bin_index        = /var/log/mysql/mariadb-bin.index
# not fab for performance, but safer
#sync_binlog          = 1
expire_logs_days      = 10
max_binlog_size         = 100M
# slaves
#relay_log            = /var/log/mysql/relay-bin
#relay_log_index      = /var/log/mysql/relay-bin.index
#relay_log_info_file  = /var/log/mysql/relay-bin.info
#log_slave_updates
#read_only
#
# If applications support it, this stricter sql_mode prevents some
# mistakes like inserting invalid dates etc.
#sql_mode             = NO_ENGINE_SUBSTITUTION,TRADITIONAL
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
default_storage_engine  = InnoDB
innodb_buffer_pool_size = 256M
innodb_log_buffer_size  = 128M
innodb_file_per_table = 1
innodb_open_files     = 400
innodb_io_capacity    = 400
innodb_flush_method   = O_DIRECT
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem

#
# * Galera-related settings
#
[galera]
# Mandatory settings
#wsrep_on=ON
#wsrep_provider=
#wsrep_cluster_address=
#binlog_format=row
#default_storage_engine=InnoDB
#innodb_autoinc_lock_mode=2
#
# Allow server to accept connections on all interfaces.
#
#bind-address=0.0.0.0
#
# Optional setting
#wsrep_slave_threads=1
#innodb_flush_log_at_trx_commit=0

[mysqldump]
quick
quote-names
max_allowed_packet    = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completion

[isamchk]
key_buffer            = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!include /etc/mysql/mariadb.cnf
!includedir /etc/mysql/conf.d/

#wsrep_on=ON
#wsrep_provider=
#wsrep_cluster_address=
#binlog_format=row
#default_storage_engine=InnoDB
#innodb_autoinc_lock_mode=2
#
# Allow server to accept connections on all interfaces.
#
#bind-address=0.0.0.0
#
# Optional setting
#wsrep_slave_threads=1
#innodb_flush_log_at_trx_commit=0

[mysqldump]
quick
quote-names
max_allowed_packet    = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completion

[isamchk]
key_buffer            = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!include /etc/mysql/mariadb.cnf
!includedir /etc/mysql/conf.d/