title: Docker Containers (MariaDb, AspNet) Can't Communicate on Compose Network
body: <p>I've setup a Docker-Compose file that creates a mariadb database and aspnet backend (both from docker files I've written). If I expose ports and run the containers outside of a compose (using localhost) or set network_mode: &quot;host&quot; in the docker-compose file then the app interacts as expected. However, using the default bridge network that the compose generates any command between containers seems to timeout.</p>
  <p>I've attempted to run a networking container (nicolaka/netshoot) attached to the same network and ping the relevant containers via the DNS name. The name resolves to the IP address and then the ping hangs, I've also run and attached a mysql container and attempted connecting to the mariadb container which results in a timeout.</p>
  <p>This all looks to be some networking issue in my setup. Config listed below, any help would be much appreciated!</p>
  <p>MariaDb DockerFile</p>
  <pre><code>ARG VERSION=10.4
  FROM mariadb/server:${VERSION}
  ENV MYSQL_ROOT_PASSWORD ****
  EXPOSE 3306
  </code></pre>
  <p>AspNet DockerFile</p>
  <pre><code>FROM mcr.microsoft.com/dotnet/aspnet:5.0
  # Container SetUp
  EXPOSE 80
  # .NET specific
  COPY ToDoListBackEnd.Api/bin/Release/net5.0/publish ToDoListBackEnd/
  WORKDIR /ToDoListBackEnd
  ENTRYPOINT [&quot;dotnet&quot;, &quot;ToDoListBackEnd.Api.dll&quot;]
  </code></pre>
  <p>ComposeFile:</p>
  <pre><code>version: '3.3'
  services:
    db: # Service Hosting MariaDb
      build: ./Database
      container_name: todolist-database
      ports:
        - &quot;6001:3306&quot;
      volumes:
        - todo-db:/var/lib/mysql
      restart: always 
      environment:
        MYSQL_ROOT_PASSWORD: ***
        MYSQL_DATABASE: ToDoList
        MYSQL_USER: root
        MYSQL_PASSWORD: ***
      
    backend: # Backend C# Service
      build: ./BackEnd
      container_name: todolist-backend
      ports:
        - &quot;5002:80&quot;
      restart: always
      depends_on: 
        - db
      links: 
        - db
  volumes:
    todo-db:
  </code></pre>
  <p>Network Config</p>
  <pre><code>{
      &quot;Name&quot;: &quot;todolist_default&quot;,
      &quot;Id&quot;: &quot;6dd07863467b35ece5e00f400ca03c0c1b9950a5f8d5a6538b47889ac2dcae68&quot;,
      &quot;Created&quot;: &quot;2021-04-21T19:39:58.329215937+01:00&quot;,
      &quot;Scope&quot;: &quot;local&quot;,
      &quot;Driver&quot;: &quot;bridge&quot;,
      &quot;EnableIPv6&quot;: false,
      &quot;IPAM&quot;: {
          &quot;Driver&quot;: &quot;default&quot;,
          &quot;Options&quot;: null,
          &quot;Config&quot;: [
              {
                  &quot;Subnet&quot;: &quot;172.23.0.0/16&quot;,
                  &quot;Gateway&quot;: &quot;172.23.0.1&quot;
              }
          ]
      },
      &quot;Internal&quot;: false,
      &quot;Attachable&quot;: true,
      &quot;Ingress&quot;: false,
      &quot;ConfigFrom&quot;: {
          &quot;Network&quot;: &quot;&quot;
      },
      &quot;ConfigOnly&quot;: false,
      &quot;Containers&quot;: {
          &quot;01f10355356ea8d194b9de6c6e9ead0af5398ad8d10dc743a70927c88532f3ef&quot;: {
              &quot;Name&quot;: &quot;todolist-database&quot;,
              &quot;EndpointID&quot;: &quot;9b69958ff0a1c9ff7cf62f3478965fdef0622fd3fe98922bebee4ebe72aa9508&quot;,
              &quot;MacAddress&quot;: &quot;02:42:ac:17:00:03&quot;,
              &quot;IPv4Address&quot;: &quot;172.23.0.3/16&quot;,
              &quot;IPv6Address&quot;: &quot;&quot;
          },
          &quot;356092a918beb6a0a021d369fd5f76e556e54ebad3c1b8fa626ce33fd66af579&quot;: {
              &quot;Name&quot;: &quot;mysqlTest&quot;,
              &quot;EndpointID&quot;: &quot;3ae06081e831c8f94bc36c59cd085561b81685da164011c5e6438ffd0d1bb6c2&quot;,
              &quot;MacAddress&quot;: &quot;02:42:ac:17:00:02&quot;,
              &quot;IPv4Address&quot;: &quot;172.23.0.2/16&quot;,
              &quot;IPv6Address&quot;: &quot;&quot;
          },
          &quot;61bbc2047065f01732ddd0e7db492c0708144cb6ede7ee0b5466c708c36d9639&quot;: {
              &quot;Name&quot;: &quot;todolist-backend&quot;,
              &quot;EndpointID&quot;: &quot;06c46938e05ba48955c75a63a65268d4259c30ad9bb7a23f2d15c04299d644da&quot;,
              &quot;MacAddress&quot;: &quot;02:42:ac:17:00:05&quot;,
              &quot;IPv4Address&quot;: &quot;172.23.0.5/16&quot;,
              &quot;IPv6Address&quot;: &quot;&quot;
          }
      },
      &quot;Options&quot;: {},
      &quot;Labels&quot;: {
          &quot;com.docker.compose.network&quot;: &quot;default&quot;,
          &quot;com.docker.compose.project&quot;: &quot;todolist&quot;,
          &quot;com.docker.compose.version&quot;: &quot;1.29.1&quot;
      },
      &quot;CreatedTime&quot;: 1619030398329
  }
  </code></pre>
  <p>my.cnf from inside the mariadb container</p>
  <pre><code># MariaDB database server configuration file.
  #
  # You can copy this file to one of:
  # - &quot;/etc/mysql/my.cnf&quot; to set global options,
  # - &quot;~/.my.cnf&quot; 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 &quot;#&quot; 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        = 600
  max_allowed_packet  = 16M
  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  = 8M
  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 &quot;tinyca&quot;.
  #
  # 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/
  </code></pre>
  <p>Thanks again for any help!</p>