挂载卷时无法运行 mariadb [英] Unable to run mariadb when mount volume

问题描述

使用以下 docker-compose.yml 文件

Using the following docker-compose.yml file

version: '2'

services:

  wordpress:
    image: wordpress
    ports:
      - 8080:80
    environment:
      WORDPRESS_DB_NAME: my_db
      WORDPRESS_DB_USER: root
      WORDPRESS_DB_PASSWORD: password
    volumes:
      - ./src:/var/www/html

  mysql:
    image: mariadb
    environment:
      MYSQL_ROOT_PASSWORD: password
    volumes:
      - ./data_dir:/var/lib/mysql

当运行 docker-compose up 命令时，它给了我以下错误

when running docker-compose up commande,its giving me following error

Starting wp_mysql_1
Starting wp_wordpress_1
Attaching to wp_mysql_1, wp_wordpress_1
wordpress_1  |
wordpress_1  | Warning: mysqli::mysqli(): (HY000/2002): Connection refused in - on line 19
wordpress_1  |
wordpress_1  | MySQL Connection Error: (2002) Connection refused
mysql_1      | 2016-11-28 15:47:02 139858949081024 [Note] mysqld (mysqld 10.1.19-MariaDB-1~jessie) starting as process 1
 ...
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Using mutexes to ref count buffer pool pages
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: The InnoDB memory heap is disabled
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory
 barrier
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Compressed tables use zlib 1.2.8
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Using Linux native AIO
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Using SSE crc32 instructions
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Initializing buffer pool, size = 256.0M
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] InnoDB: Completed initialization of buffer pool
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] InnoDB: auto-extending data file ./ibdata1 is of a different
size 0 pages (rounded down to MB) than specified in the .cnf file: initial 768 pages, max 0 (relevant if non-zero) pages
!
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] InnoDB: Could not open or create the system tablespace. If yo
u tried to add new data files to the system tablespace, and it failed here, you should now edit innodb_data_file_path in
 my.cnf back to what it was, and remove the new ibdata files InnoDB created in this failed attempt. InnoDB only wrote th
ose files full of zeros, but did not yet use them in any way. But be careful: do not remove old data files which contain
 your precious data!
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] Plugin 'InnoDB' init function returned error.
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
mysql_1      | 2016-11-28 15:47:03 139858949081024 [Note] Plugin 'FEEDBACK' is disabled.
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] Could not open mysql.plugin table. Some plugins may be not lo
aded
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] Unknown/unsupported storage engine: InnoDB
mysql_1      | 2016-11-28 15:47:03 139858949081024 [ERROR] Aborting
mysql_1      |
wp_mysql_1 exited with code 1
wordpress_1  |
wordpress_1  | Warning: mysqli::mysqli(): php_network_getaddresses: getaddrinfo failed: Name or service not known in - o
n line 19
wordpress_1  |
wordpress_1  | Warning: mysqli::mysqli(): (HY000/2002): php_network_getaddresses: getaddrinfo failed: Name or service no
t known in - on line 19
wordpress_1  |
wordpress_1  | MySQL Connection Error: (2002) php_network_getaddresses: getaddrinfo failed: Name or service not known

但是如果我从 mysql 映像中删除了卷，那么它工作正常！在需要持久化数据时如何挂载卷.

but if I removed the volumes from mysql image, then it works fine! How can I mount the volume as I need data to be persisted.

推荐答案

其实是 MariaDB 的问题.您不能使用 Docker 将 MariaDB 的文件夹挂载到主机上，因为它将共享文件/文件夹的权限提供给数据库容器作为 root 拥有，并且只能由 root 写入.解决方案是使用 docker-compose 命名卷.如 docker 文档中所述:
Docker 有两个选项让容器将文件存储在主机中，以便即使在容器停止后文件也能持久保存:卷和绑定挂载.如果你在 Linux 上运行 Docker，你也可以使用 tmpfs 挂载.

It's actually a problem with MariaDB. You cannot mount the folder for MariaDB to the host using Docker because it presents the shared files/folders permissions to the database container as root owned with writable only by root. The solution is to use docker-compose named volumes. As stated in docker documentation:
Docker has two options for containers to store files in the host machine, so that the files are persisted even after the container stops: volumes, and bind mounts. If you’re running Docker on Linux you can also use a tmpfs mount.

您尝试使用的是无法与 MariaDB 一起使用的绑定挂载.所以我们可以使用 docker volume.

What you are trying to use is the bind-mount which does not works with MariaDB. So we can use docker volume for that.

创建卷时，它会存储在 Docker 主机上的目录中.当您将卷挂载到容器中时，此目录就是挂载到容器中的目录.这类似于绑定挂载的工作方式，只是卷由 Docker 管理并且与主机的核心功能隔离.卷存储在由 Docker 管理的主机文件系统的一部分(Linux 上的/var/lib/docker/volumes/).因此，将您的 docker-compose 文件更改为:-

When you create a volume, it is stored within a directory on the Docker host. When you mount the volume into a container, this directory is what is mounted into the container. This is similar to the way that bind mounts work, except that volumes are managed by Docker and are isolated from the core functionality of the host machine. Volumes are stored in a part of the host filesystem which is managed by Docker(/var/lib/docker/volumes/ on Linux). So change your docker-compose file as:-

version: '2'

services:

      wordpress:
         image: wordpress
         ports:
           - 8080:80
         environment:
           WORDPRESS_DB_NAME: my_db
           WORDPRESS_DB_USER: root
           WORDPRESS_DB_PASSWORD: password
         volumes:
           - ./src:/var/www/html

       mysql:
         image: mariadb
         environment:
           MYSQL_ROOT_PASSWORD: password
         volumes:
           - db_data:/var/lib/mysql
volumes:
   db_data:

即在 mysql 服务下使用命名卷并在顶级卷键中声明它.这将告诉 docker-compose 创建一个 Docker 托管卷，并且您的 MariaDB 数据将备份/保存在主机上的/var/lib/docker/volumes/_db_data/_data 目录中.

i.e. use a named volume under mysql service and declare it in top level volumes key. This will tell docker-compose to create a Docker mananged volume and your MariaDB data is backed up/persisted at /var/lib/docker/volumes/_db_data/_data directory on host machine.

在运行 docker-compose up 命令后，如果你这样做了码头工人卷 ls然后你可以看到 docker-compose 创建的卷.

Also after running docker-compose up command if you do docker volume ls then you can see docker-compose created volume.

这篇关于挂载卷时无法运行 mariadb的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！