I want access /etc/php5/apache2 in my container, where f.e. php.ini is located.
As soon as I mount my volume...it seems the container can't write the default php.ini to the apache2 folder, because apache2 folder and config folder on host are empty.
docker config:
./config/:/etc/php5/apache2
I have also tested Z flag without any success. Folder config on host is read/write/excutable by everyone.
A volume shadows data in the container, e.g. if there is bla.txt in the folder in the container, after mounting you won't see the file.
If you only need to see the file, you can go into the the container using docker exec -it <id> /bin/sh and then look into the file.
Alternatively use docker cp to copy the file, but I never needed that.
Related
I have a docker image, and I am running it now (finishing with bash)
When I do, I have a file structure inside the container.
However, this is not some file structure mapped (with -v) from outside the container. These files and folders exist only inside the container.
My question is, since it is bothersome to be opening each file with vi and navigating from the terminal, is there a way that I can open vscode on these files?
Be aware that these files do not exist outside the container
I found how to do it from this link
However I used the "attach to running container" command
I rarely do that but when I have to I usually mount an empty volume to the container, then exec into the container copy the folder which I need into that empty volume, which is then replicated on my host machine. From my host machine I then open it in vscode.
However please be careful if you have sensitive information in that container, not to expose something by accident.
So the steps are:
Create empty volume ( docker-compose example )
Note do not overwrite the folder/file which you want to extract. containerpath is path which does not exist in the container prior to creating it.
volume:
- ./hostpath:/containerpath
Find docker id so that you can use it to exec into it:
docker ps
Exec into the container:
docker exec -it <container_id> /bin/sh
Copy the file/folder to that empty volume:
cp -r folder containerpath
Exit the container and look at your files in ./hostpath folder.
I would like to have a Docker Volume that mounts to a container. This volume would need to be somewhere other than the default location of volumes, preferably somewhere on the Desktop. This is because I am running a web server and would like some directories to be editable by something like VSCode so I don't always have to go inside the container to edit a file. I am not going to be using Docker Compose and instead will be using a Docker File for the container. The functionality I'm going for is the following equivalent of Docker Compose, but in a Dockerfile or through docker run, whichever is easiest to accomplish:
volumes:
- <local-dir>:<container-dir>
This directory will need to be editable LIVE and using the Dockerfile ADD command will not suffice, because after building, the image gets put into a tar archive and cannot be accessed after that.
with this solution you can move even A live container to new partition:
Add a configuration file to tell the docker daemon what is the location of the data directory
Using your preferred text editor add a file named daemon.json under the directory /etc/docker. The file should have this content:
{
"data-root": "/path/to/your/docker"
}
Copy the current data directory to the new one
sudo rsync -aP /var/lib/docker/ /path/to/your/docker
Rename the old docker directory
sudo mv /var/lib/docker /var/lib/docker.old
Restart the docker daemon
sudo service docker start
resource: https://www.guguweb.com/2019/02/07/how-to-move-docker-data-directory-to-another-location-on-ubuntu/
You can mount a directory from your host inside your container when you launch the docker container, using -v or --volume
docker run -v /path/to/desktop/some-dir:/container-dir/path <docker-image>
Volumes specified in the Dockerfile, as you exemplified, will automatically create those volumes under /var/lib/docker/volumes/ every time a container is launched from that image, but it is NOT recommended have these volumes altered by non-Docker processes.
I made a docker image called myImage, there is a folder: /data I want to let the user edit it by themselves. I read that -v flag can mount the volume, so I used it like following:
I run the container with this command:
docker run -v /my_local_path:/data -it myImage /bin/bash
But surprisingly, docker cleared all the files in /data in the container. But this is not I want... I want actually the host can get all the files from /data... :(
How can I do that?
When you share a volume like this, the volume on the host overwrites the volume in the container, so the files in the container's folder will be removed.
What you need to do is put the files in the container in folder A (a folder in the container). Mount folder B (another folder in the container). Then AFTER the volume is mounted, move the files from folder A to folder B. Then these files will be both available to the host and inside the container.
You can achieve this 'move files' operation using a RUN or an ENTRYPOINT script in your Dockerfile.
See Run a script in Dockerfile
Sorry, I forget if you need RUN or ENTRYPOINT (or if either will work) but one of these will definitely do it.
I think you want ENTRYPOINT because an ENTRYPOINT script runs AFTER the container is created. Thus it will run after the volume is mounted.
I created own Dockerfile, during building I inserted to /opt/wilfly/log my log4j.xml.
Now I need create volume /mnt/data/logs/application:/opt/wildfly/log
I run command
sudo docker run --name=myapp -v /mnt/data/logs/application:/opt/wildfly/log -d -i -t application
But when I look in docker container, folder /opt/wilfly/log is empty. In this folder should by log4j.xml.
Thank you.
Maybe you should move it into another directory.
For example move log4j.xml to /opt/wilfly/ and set logging path to /opt/wilfly/log.
When you run the container, log4j.xml will not disappear.
When you mount the data, the folder from your host "override" your mounted folder within the container.
Thus, there are some options you can do:
copy the log4j.xml into your local /mnt/data/logs/application folder and run the container as you did.
remove the -v /mnt/data/logs/application:/opt/wildfly/log and use the original log4j.xml that you were added during the image build.
Please note that you can also mount only the file if you like (rather than the entire floder): -v /mnt/data/logs/application/log4j.xml:/opt/wildfly/log/log4j.xml but it won't change the behavior - the file from your host will be mounted into the container and not in the opposite direction.
This application I'm trying to Dockerize has configuration files in the root of the install dir. If I use VOLUME to mount the install dir on the host, I'll end up with the application on the host, too. I only want to store the configuration files on the host.
Should I use hard links in the container and use VOLUME to mount the dir that has the hardlinks? Do hard links even work in a container?
You can mount individual files. Below is from the docker documentation https://docs.docker.com/engine/userguide/containers/dockervolumes/
Mount a host file as a data volume
The -v flag can also be used to mount a single file - instead of just
directories - from the host machine.
$ docker run --rm -it -v ~/.bash_history:/root/.bash_history ubuntu /bin/bash
This will drop you into a bash shell in a new container, you will have
your bash history from the host and when you exit the container, the
host will have the history of the commands typed while in the
container.
Note: Many tools used to edit files including vi and sed --in-place may result in an inode change. Since Docker v1.1.0, this will produce an error such as “sed: cannot rename ./sedKdJ9Dy: Device
or resource busy”. In the case where you want to edit the mounted
file, it is often easiest to instead mount the parent directory.