docker 容器的用戶權限是否會影響主機對 docker-compose.yml 中掛載卷的權限？

Question

我有docker-compose.yml如下，

version: '2'
services:
  mysql:
    image: centos/mysql-56-centos7:latest
    restart: always
    container_name: mysql
    environment:
       - MYSQL_ROOT_PASSWORD=111111
    volumes:
      - /etc/localtime:/etc/localtime
      - /data/mysql:/var/lib/mysql/data
    ports:
      - 3306:3306

centos/mysql-56-centos7是來自 Docker Hub 的鏡像。 我用docker-compose up來啟動容器，但是總是失敗，原因是：

Can't create test file /var/lib/mysql/data/cdef45a5817c.lower-test

完整信息：

    Creating network "mysql_default" with the default driver
    Creating mysql ... ^M
    ^[[1A^[[2K^MCreating mysql ... ^[[32mdone^[[0m^M^[[1BAttaching to mysql
    ^[[36mmysql    |^[[0m => sourcing 20-validate-variables.sh ...
    ^[[36mmysql    |^[[0m => sourcing 25-validate-replication-variables.sh ...
    ^[[36mmysql    |^[[0m => sourcing 30-base-config.sh ...
    ^[[36mmysql    |^[[0m ---> 16:39:17     Processing basic MySQL configuration files ...
    ^[[36mmysql    |^[[0m => sourcing 60-replication-config.sh ...
    ^[[36mmysql    |^[[0m => sourcing 70-s2i-config.sh ...
    ^[[36mmysql    |^[[0m ---> 16:39:17     Processing additional arbitrary  MySQL configuration provided by s2i ...
    ^[[36mmysql    |^[[0m => sourcing 40-paas.cnf ...
    ^[[36mmysql    |^[[0m => sourcing 50-my-tuning.cnf ...
    ^[[36mmysql    |^[[0m ---> 16:39:17     Initializing database ...
    ^[[36mmysql    |^[[0m ---> 16:39:17     Running mysql_install_db --rpm --datadir=/var/lib/mysql/data
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 0 [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 0 [Note] /opt/rh/rh-mysql56/root/usr/libexec/mysqld (mysqld 5.6.38) starting as process 30 ...
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Warning] Can't create test file /var/lib/mysql/data/a5d11f4146dd.lower-test
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Warning] Can't create test file /var/lib/mysql/data/a5d11f4146dd.lower-test
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Using atomics to ref count buffer pool pages
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: The InnoDB memory heap is disabled
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Memory barrier is not used
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Compressed tables use zlib 1.2.7
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Using Linux native AIO
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Using CPU crc32 instructions
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Initializing buffer pool, size = 32.0M
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] InnoDB: Completed initialization of buffer pool
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 7f1048c42840  InnoDB: Operating system error number 13 in a file operation.
    ^[[36mmysql    |^[[0m InnoDB: The error means mysqld does not have the access rights to
    ^[[36mmysql    |^[[0m InnoDB: the directory.
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 7f1048c42840  InnoDB: Operating system error number 13 in a file operation.
    ^[[36mmysql    |^[[0m InnoDB: The error means mysqld does not have the access rights to
    ^[[36mmysql    |^[[0m InnoDB: the directory.
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] InnoDB: Creating or opening ./ibdata1 failed!
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] InnoDB: Could not open or create the system tablespace. If you 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 those 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!
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] Plugin 'InnoDB' init function returned error.
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] Unknown/unsupported storage engine: InnoDB
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [ERROR] Aborting
    ^[[36mmysql    |^[[0m
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] Binlog end
    ^[[36mmysql    |^[[0m 2020-01-10 16:39:17 30 [Note] /opt/rh/rh-mysql56/root/usr/libexec/mysqld: Shutdown complete

如果我從docker-compose.yml刪除這一行/data/mysql:/var/lib/mysql/data ，容器可以正常啟動。

我在主機docker-compose up以 root 權限運行docker-compose up ，怎么會出現權限問題？ 我不知道在 docker 容器中使用什么用戶權限啟動 MySQL 進程，但這如何影響主機的權限？

---

其他信息：

在主機上，似乎沒有啟用 selinux

# getenforce
Disabled

我 chmod mysql 文件夾，所以

# ls -l /data
total 0
drwxrwxrwx 2 root root 6 Jan  9 15:28 mysql

Answer 1

啟動docker-compose up與主機上的哪個用戶無關。 當您將/data/mysql掛載到容器中時，容器內的掛載路徑將具有與主機上相同的權限和所有權。 容器內的進程無法寫入此路徑。