Question

我创建了一个docker MySql 5.7映像，然后想要更改几个名称。我的docker-compose.yml文件最终像这样

version: '3.3'

services:
  db:
    image: mysql:5.7
    restart: always
    environment:
      MYSQL_DATABASE: 'maps_data'
      # So you don't have to use root, but you can if you like
      MYSQL_USER: 'myuser'
      # You can use whatever password you like
      MYSQL_PASSWORD: 'password'
      # Password for root access
      MYSQL_ROOT_PASSWORD: 'password'
    ports:
      # <Port exposed> : < MySQL Port running inside container>
      - '3406:3306'
    expose:
      # Opens port 3406 on the container
      - '3406'
      # Where our data will be persisted
    volumes:
      - my-db:/var/lib/mysql
# Names our volume
volumes:
  my-db:

我想从头开始重建映像，并认为“ docker-compose up -d --force-recreate”是解决之道...

localhost:maps davea$ docker-compose down
Stopping maps_db_1 ... done
Removing maps_db_1 ... done
Removing network maps_default
localhost:maps davea$ 
localhost:maps davea$ docker-compose up -d --force-recreate
Creating network "maps_default" with the default driver
Creating maps_db_1 ... done
maps_db_1 is up-to-date
Attaching to maps_db_1
db_1  | 2020-01-28 23:16:19+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.29-1debian9 started.
db_1  | 2020-01-28 23:16:19+00:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
db_1  | 2020-01-28 23:16:19+00:00 [Note] [Entrypoint]: Entrypoint script for MySQL Server 5.7.29-1debian9 started.
db_1  | 2020-01-28T23:16:20.051193Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
db_1  | 2020-01-28T23:16:20.052820Z 0 [Note] mysqld (mysqld 5.7.29) starting as process 1 ...
db_1  | 2020-01-28T23:16:20.056843Z 0 [Note] InnoDB: PUNCH HOLE support available
db_1  | 2020-01-28T23:16:20.056912Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
db_1  | 2020-01-28T23:16:20.056928Z 0 [Note] InnoDB: Uses event mutexes
db_1  | 2020-01-28T23:16:20.056944Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
db_1  | 2020-01-28T23:16:20.056959Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
db_1  | 2020-01-28T23:16:20.056975Z 0 [Note] InnoDB: Using Linux native AIO
db_1  | 2020-01-28T23:16:20.057616Z 0 [Note] InnoDB: Number of pools: 1
db_1  | 2020-01-28T23:16:20.057757Z 0 [Note] InnoDB: Using CPU crc32 instructions
db_1  | 2020-01-28T23:16:20.059523Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
db_1  | 2020-01-28T23:16:20.070356Z 0 [Note] InnoDB: Completed initialization of buffer pool
db_1  | 2020-01-28T23:16:20.073066Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
db_1  | 2020-01-28T23:16:20.084799Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
db_1  | 2020-01-28T23:16:20.097204Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
db_1  | 2020-01-28T23:16:20.097391Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
db_1  | 2020-01-28T23:16:20.134350Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
db_1  | 2020-01-28T23:16:20.135692Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
db_1  | 2020-01-28T23:16:20.135748Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
db_1  | 2020-01-28T23:16:20.136582Z 0 [Note] InnoDB: Waiting for purge to start
db_1  | 2020-01-28T23:16:20.192038Z 0 [Note] InnoDB: 5.7.29 started; log sequence number 12442166
db_1  | 2020-01-28T23:16:20.192864Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
db_1  | 2020-01-28T23:16:20.193111Z 0 [Note] Plugin 'FEDERATED' is disabled.
db_1  | 2020-01-28T23:16:20.194918Z 0 [Note] InnoDB: Buffer pool(s) load completed at 200128 23:16:20
db_1  | 2020-01-28T23:16:20.198841Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them.
db_1  | 2020-01-28T23:16:20.198900Z 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory.
db_1  | 2020-01-28T23:16:20.199651Z 0 [Warning] CA certificate ca.pem is self signed.
db_1  | 2020-01-28T23:16:20.199712Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
db_1  | 2020-01-28T23:16:20.200248Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
db_1  | 2020-01-28T23:16:20.200400Z 0 [Note] IPv6 is available.
db_1  | 2020-01-28T23:16:20.200413Z 0 [Note]   - '::' resolves to '::';
db_1  | 2020-01-28T23:16:20.200633Z 0 [Note] Server socket created on IP: '::'.
db_1  | 2020-01-28T23:16:20.204771Z 0 [Warning] Insecure configuration for --pid-file: Location '/var/run/mysqld' in the path is accessible to all OS users. Consider choosing a different directory.
db_1  | 2020-01-28T23:16:20.217005Z 0 [Note] Event Scheduler: Loaded 0 events
db_1  | 2020-01-28T23:16:20.217626Z 0 [Note] mysqld: ready for connections.
db_1  | Version: '5.7.29'  socket: '/var/run/mysqld/mysqld.sock'  port: 3306  MySQL Community Server (GPL)

但是，当我以root用户身份登录时，在那里看不到我的数据库“ maps_data”。我在进行更改之前就看到了旧的“ db”数据库...

localhost:maps davea$ mysql -u root -h 127.0.0.1 --port=3406 -p 
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.29 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases
    -> ;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db                 |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

完全从头开始并重建docker MySql映像的正确方法是什么？

Answer 1

告诉docker-compose通过向下传递--rmi标志来删除图像：

docker-compose down --rmi all

这告诉compose停止并删除所有容器，网络，并删除docker-compose文件中任何服务使用的所有映像。此外，您可以传递--volumes来删除所有命名的卷（在您的情况下为my-db）。但是，这将导致删除docker-compose文件中的命名卷，并且您将丢失该数据。确保这是您想要的。

然后，要使用新图像重新运行应用程序，请在启动容器之前将docker-compose up与--build选项一起使用以构建图像。

docker-compose up -d --build

有关更多选项，请参阅docker-compose参考资料up和down。

Answer 2

docker-compose的--force-recreate将删除容器，并根据提供的映像名称/ Id（在您的情况下为mysql：5.7）构建一个新容器。我可以想象这正在发生。您可以判断是否在docker-compose up ... --force-recreate之前和之后查看容器ID。如果容器的ID发生变化，则docker-compose确实确实从mysql：5.7映像创建了一个新容器。

如果查看docker-compose yaml文件，可以看到它将使用名为'my-db'的docker卷安装在容器内的/ var / lib / mysql中。 Docker卷是持久性的（这是其主要用例之一），因此，在创建新容器时，它将“ my-db”卷挂载回/ var / lib / mysql，这会将您的数据持久化到新容器中。

https://docs.docker.com/storage/volumes/

卷是持久化由Docker容器生成和使用的数据的首选机制。

如果您想真正地从零开始，您要做的就是发出docker-compose down（这将删除容器），并确保还删除了“ my-db”卷（使用docker卷） ls）。如果该卷仍然存在，请使用docker volume rm my-db删除该卷。之后，发出docker-compose up -d，它将建立一个新卷（该卷将为空），并且新容器在/ var / lib / mysql中将看不到任何文件。

为什么不“ --force-recreate”重建我的docker mysql镜像？

2 个答案: