Troubleshooting Failure to Mount File or Directory Using. and Relative Path in docker run

The './' relative path is allowed in docker-compose. yml files

version: '3'
 ...
 volumes:
 - ./init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro
 - ./mongo-volume:/data/db
 ...

The init-mongo. js file in the current path is mounted to/docker-entrypoint-initdb. d/init-mongo. js in the container and set to read-only;

The mongo-volume directory under the current path is mounted into the container/data/db, which is automatically created if mongo-volume does not exist

However, if it is docker, run, it cannot use relative path as above 1

>>> docker run -d --restart always -p 27017-27019:27017-27019 -e MONGO_INITDB_DATABASE=job -e MONGO_INITDB_ROOT_USERNAME=root -e MONGO_INITDB_ROOT_PASSWORD=root -v $PWD/init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro -v ./mongo-volume:/data/db --name my-mongo-container mongo
docker: Error response from daemon: create ./init-mongo.js: "./init-mongo.js" includes invalid characters for a local volume name, only "[a-zA-Z0-9][a-zA-Z0-9_.-]" are allowed. If you intended to pass a host directory, use absolute path.
See 'docker run --help'.

Need to use $PWD instead of the dot number '.'

>>> docker run -d --restart always -p 27017-27019:27017-27019 -e MONGO_INITDB_DATABASE=job -e MONGO_INITDB_ROOT_USERNAME=root -e MONGO_INITDB_ROOT_PASSWORD=root -v $PWD/init-mongo.js:/docker-entrypoint-initdb.d/init-mongo.js:ro -v $PWD/mongo-volume:/data/db --name my-mongo-container mongo
3081e25a20fa8b2e95850897b3b32b08da298f73d7e458119fa3f2c85b45f020

Added: Docker-v No permissions on mounted directory Permission denied

1. Problems

Today, when using docker to mount redis, you always report errors

docker run -v /home/redis/redis.conf:/usr/local/etc/redis/redis.conf --name redis2 -p 6378:6379 redis redis-server /usr/local/etc/redis/redis.conf

Then 1 directly reports an error:

Fatal error, can't open config file '/usr/redis/redis.conf'

2. Screening process

The same is true of viewing logs

Then I removed the place where I used the configuration file

docker run -v /home/redis/redis.conf:/usr/local/etc/redis/redis.conf --name redis2 -p 6378:6379 redis

Then enter the container

docker exec -it redis2 /bin/bash

Then go to the mounted folder

cd /usr/local/etc/redis

Found error:

cannot open directory '.': Permission denied

That is, there is no permission

3. Causes and solutions

3.1 Reasons

The security module selinux in centos7 disables the authority

3.2 Solution

There are three ways to solve this problem:

1. Add-privileged=true at run time

docker run -v /home/redis/redis.conf:/usr/local/etc/redis/redis.conf --name redis2 --privileged=true redis redis-server /usr/local/etc/redis/redis.conf

2. Temporarily close selinux and then open it again

[root@localhost tomcat]# setenforce 0
[root@localhost tomcat]# setenforce 1

3. Add the linux rule to add the directory to be mounted to the selinux white list

Change the format of the security text as follows

chcon [-R] [-t type] [-u user] [-r E113EN] file or directory

Select parameters:

-R: All directories under this directory are also modified at the same time;

-t: followed by the type field of the security article, for example httpd_sys_content_t;

-u: followed by identification, e.g. system_u;

-r: Back street color, for example system_r

Execution:

chcon -Rt svirt_sandbox_file_t /home/redis/redis.conf

4. Lessons from docker mounting

4.1 Container directory cannot be a relative path

4.2 If the host directory does not exist, it will be automatically generated

4.3 What if the directory of the host is a relative path

We can get the answer to this question by looking at the 1 part of the container "Mounts" through the docker inspect command.