Docker Volumes mounting issue
I am trying to dynamically mount a volume from the container to the host and it works but there is a hitch. I am using the following command:
docker run -it --name Test1 -v $HOME/.myapp_configs/specificConfig.txt:/bin/specificConfig.txt:rw docker-image /bin/bash
The issue lies in that if the mount point on the host does not exist the docker command creates it but assigns it
root:root rather than
$USER:$USER like I would expect. I gather that this is more than likely a direct result of the namespace mapping issue that has been identified with Docker.
Does anyone have any thoughts on how I can force the host mount point to be created with the appropriate permissions? i.e.
drwxr-xr-x. 3 $USER $USER 31 Aug 21 15:02 ~/.myapp_configs/specificConfig.txt
drwxr-xr-x. 3 root root 31 Aug 21 15:02 ~/.myapp_configs/specificConfig.txt
One Solution collect form web for “Docker Volumes mounting issue”
What about making sure the file exists before running the container?
the command could look like:
test -f $HOME/.myapp_configs/specificConfig.txt || touch $HOME/.myapp_configs/specificConfig.txt docker run -it --name Test1 -v $HOME/.myapp_configs/specificConfig.txt:/bin/specificConfig.txt:rw docker-image /bin/bash
test -f <some file>will have exit status
0if the file exists
||will execute the following command only if the previous command exit status is different than
touch <some file>modify an existing file modification time, or (and this is our case) create an empty file
Of course, if inside your container lies some code that acts differently whether the file exists or not, then you would have to adapt that code to check if the file is empty instead.