CODEWITHSUNDEEP
mysqldocker
Oleg Sukhov
Oleg Sukhov

Reputation: 41

MySQL docker container receives SHUTDOWN command

everyone. I have noticed strange behavior during MySQL docker container startup. Basically I'm trying to run the following command

docker run --name mysql -e MYSQL_ROOT_PASSWORD=root -d mysql:8.0.29

but after that I see from the logs that container after successful startup suddenly receives SHUTDOWN command, and reinitialize database again

2022-07-25T19:33:26.423537Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.29)  MySQL Community Server - GPL.

Here is all the logs:

2022-07-25 19:33:19+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1.el8 started.
2022-07-25 19:33:19+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2022-07-25 19:33:19+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 8.0.29-1.el8 started.
2022-07-25 19:33:19+00:00 [Note] [Entrypoint]: Initializing database files
2022-07-25T19:33:19.770157Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.29) initializing of server in progress as process 42
2022-07-25T19:33:19.775554Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-07-25T19:33:20.037982Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-07-25T19:33:21.277581Z 6 [Warning] [MY-010453] [Server] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
2022-07-25 19:33:23+00:00 [Note] [Entrypoint]: Database files initialized
2022-07-25 19:33:23+00:00 [Note] [Entrypoint]: Starting temporary server
2022-07-25T19:33:23.494658Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.29) starting as process 91
2022-07-25T19:33:23.505604Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-07-25T19:33:23.590481Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-07-25T19:33:23.778598Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2022-07-25T19:33:23.778621Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2022-07-25T19:33:23.779801Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2022-07-25T19:33:23.790924Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Socket: /var/run/mysqld/mysqlx.sock
2022-07-25T19:33:23.790961Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.29'  socket: '/var/run/mysqld/mysqld.sock'  port: 0  MySQL Community Server - GPL.
2022-07-25 19:33:23+00:00 [Note] [Entrypoint]: Temporary server started.
'/var/lib/mysql/mysql.sock' -> '/var/run/mysqld/mysqld.sock'
Warning: Unable to load '/usr/share/zoneinfo/iso3166.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/leapseconds' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/tzdata.zi' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone.tab' as time zone. Skipping it.
Warning: Unable to load '/usr/share/zoneinfo/zone1970.tab' as time zone. Skipping it.

2022-07-25 19:33:24+00:00 [Note] [Entrypoint]: Stopping temporary server
2022-07-25T19:33:24.911894Z 10 [System] [MY-013172] [Server] Received SHUTDOWN from user root. Shutting down mysqld (Version: 8.0.29).
2022-07-25T19:33:26.423537Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.29)  MySQL Community Server - GPL.
2022-07-25 19:33:26+00:00 [Note] [Entrypoint]: Temporary server stopped

2022-07-25 19:33:26+00:00 [Note] [Entrypoint]: MySQL init process done. Ready for start up.

2022-07-25T19:33:27.122487Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.29) starting as process 1
2022-07-25T19:33:27.128121Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2022-07-25T19:33:27.217345Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2022-07-25T19:33:27.410605Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2022-07-25T19:33:27.410659Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2022-07-25T19:33:27.412287Z 0 [Warning] [MY-011810] [Server] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
2022-07-25T19:33:27.431360Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2022-07-25T19:33:27.431373Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.29'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server - GPL.

And after second attempt container is up and running normally. So my question is - how to identify what causes to the SHUTDOWN command?

Upvotes: 4

Views: 6340

Answers (1)

David Maze
David Maze

Reputation: 158898

That's a normal consequence of the way the mysql image runs its first-time initialization scripts. Note the Initializing database files message and the Temporary server started...Temporary server stopped around the first Received SHUTDOWN message.

You can see this logic in the entrypoint script itself. That script runs (using shell functions defined previously in the script, trimmed down somewhat)

# there's no database, so it needs to be initialized
if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
  docker_init_database_dir "$@"

  mysql_note "Starting temporary server"
  docker_temp_server_start "$@"
  mysql_note "Temporary server started"

  docker_setup_db
  docker_process_init_files /docker-entrypoint-initdb.d/*

  mysql_note "Stopping temporary server"
  docker_temp_server_stop
  mysql_note "Temporary server stopped"
fi

The mysql_note lines are visible in the container output you quote.

More specifically, the temporary server is accessible over a Unix socket within the container filesystem, but it is not accessible over the network. This gives a point where the database hasn't been set up yet, but it's still possible to run local mysql commands, for example from the initdb scripts. Once this phase has been complete, then the database restarts with its normal options.

If you're probing to see if the database is ready yet, maybe using a mysql client in a shell loop or a TCP client like the wait-for script, this means that the database won't appear "ready" until all of the initdb scripts have run.

Upvotes: 2

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