Want to open/attach virtual disk from vhd share inside a docker windows container based on mcr.microsoft.com/windows/server:ltsc2022, it throws "A virtual disk support provider for the specified file was not found". Does windows container support to open/attach vhd file at runtime?
Code used to OpenVirtualDisk is as below.
[DllImport("virtdisk.dll", CharSet = CharSet.Unicode)]
internal static extern long OpenVirtualDisk(ref VIRTUAL_STORAGE_TYPE virtualStorageType, string path, VirtualDiskAccessMask virtualDiskAccessMask, OPEN_VIRTUAL_DISK_FLAG fags, ref OPEN_VIRTUAL_DISK_PARAMETERS prameters, ref IntPtr handle);
Can you please provide more details on the environment you're running? To your question more specifically I think the ideal would be to mount the VHD file on the host and mount it when you run the container. However, I'm not sure you have a simple test/dev environment with Docker only or this is running on Kubernetes or something else.
To mount a volume on Windows containers, you can use:
docker run -v c:\ContainerData:c:\data:RO for read-only access
docker run -v c:\ContainerData:c:\data:RW for read-write access
docker run -v c:\ContainerData:c:\data for read-write access (default)
For more details, check out the docs page: https://learn.microsoft.com/virtualization/windowscontainers/manage-containers/persistent-storage
Related
I have docker-compose file with volumes section for given container:
video-streaming:
image: video-streaming
build:
context: ./video-streaming
dockerfile: Dockerfile-dev
container_name: video-streaming
volumes:
- /tmp/history/npm-cache:/root/.npm:z
I'm running docker on windows and image is linux based.
When I enter container and add file to /root/.npm and then close the container and run it again then the file is still there so this volume works. But the question is where can I find it's location on Windows host?
You should find the volumes in C:\ProgramData\docker\volumes. The filename will be a hash, which you can check with docker inspect.
If not, then note that you are simply mounting a host directory /tmp/history/npm-cache to your container. This directory is your volume.
When using docker for windows the question is if you are using the old Docker Toolbox or the newer ones that use WSL/WSL2
Docker Desktop configured Linux Containers and WSL/WSL2
The docker engine is actually not running on the windows, but inside the WSL instance, docker desktop makes docker commands available on the windows for ease of use.
So the volumes are probably inside that WSL instance (linux)
you can find out what WSL instances you have by typing wsl -l in powershell.
their file-system is available in \\\wsl$ path on windows.
In your case, the volume is not named, its in the exact location you specified for it.
/tmp/history/npm-cache but inside the WSL instance that docker engine is installed on.
Through WSL
in powershell write wsl ls /tmp/history, you should see npm-cache there.
wsl command allows piping linux commands that will be run on the actual linux wsl instance (default one) which is probably the one running the docker engine.
alternatively, you can connect to that linux by just typing wsl and going to that path cd /tmp/history
once inside the wsl instance you can write explorer.exe . to open explorer in that location (on windows)
notice that the path will always start with \\wsl$ so you can go to that path on windows and see all of you wsl instances and their file-systems, try to search for "npm-cache" in explorer, you might find it.
via Docker commands
docker volume ls will give you all of the available volumes. yours is not named, so its probably one of the 'UUID' ones. you can inspect each one to find its location (probably still inside the wsl instance)
docker volume inspact {the-uuid-of-the-volume}
ones you inspect it, you will see each volume has a Mountpoint field which points to the location of the volume (inside the wsl instance)
unnamed volumes are created with different permissions from your user, so you might need sudo to interact with them via the wsl terminal.
if its through windows file explorer on \\wsl$ you might not need extra permissions.
When we install any application there creates lots of file structure and also generates logs file in specified path of the application. When we are running same application in docker container , its also creates those files. How can we access those file . As I know we can use docker exec command with bash to interact in command prompt or terminal but is it possible to access same using winscp or gui based any 3rd party tools.
You could mount a volume on the container, so the "locally" generated docker files can be accessed from the host. For example:
docker run -v host_dir:container_dir yourDocker (...)
Your docker's process will save the files to his local container_dir, and you could access them via your host's host_dir.
Need to know where docker volumes are located when using the docker machine on macOS.
The installation is using boot2docker, so the VM works behind.
Example:
docker volume create test-data
docker inspect shows a path, but where can I find the specific (physical) location?
It’s inside the virtual machine and isn’t directly accessible from the host.
Debug-level commands like docker volume inspect will give you a path, but they really are only for emergency debugging and not for routine use. If you have a way to get a shell in the VM you can see that path, but you really shouldn’t be directly accessing files there, and you shouldn’t be routinely docker inspecting anything.
macOS use a virtual machine it's different to linux where you can access to volumes from /var/lib/docker/volumes.
For macOS you should connect to a VM to find your volumes.
If you use persistent data volumes in Docker, and you want to access them with command-line.
If your docker host is Linux, that’s not a problem; you can find Docker volumes by /var/lib/docker/volumes path.
However, that’s not the case when you use Docker for Mac.
Try to cd /var/lib/docker/volumes from your MacOS terminal, you ‘ll get nothing.
You see, your Mac machine isn’t a real Docker host. Docker for Mac runs a virtual machine and hides it from you to make things simple.
So, to access persistent volumes created by Docker for Mac, you need to connect on that VM.
In order to accomplish this, we need to use a serial terminal on Mac. There’s a terminal application called “screen” that’s going to help us.
We need to “screen into” the Docker driver by executing a command:
screen
~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty
screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty
You should see a blank screen, just press Enter , and after a while, you should see a command line prompt
Now you’re inside Docker’s VM and you can cd into volumes dir by typing: cd /var/lib/docker/volumes
Profit, you got there!
If you need to transfer files from your MacOS host into Docker host you can refer to File Sharing
Hope this helps you!
If you have installed docker using snap then volumes are located at:
/var/snap/docker/common/var-lib-docker/volumes/
location of volumes when using docker official install
/var/lib/docker/volumes/
Normally, if you want to "know" where a volume lives, you would want to map a volume to the local filesystem. When you create a named volume you are just allocating "shared" storage. However, if your really need to know, run this command:
docker volume inspect test-data
Context:
I have a Java Spring Boot Application which has been deployed to run on a Docker Container. I am using Docker Toolbox to be precise.
The application exposes a few REST API's to upload and download files. The application works fine on Docker i.e. i'm able to upload and download files using API.
Questions:
In the application I have hard coded the path as something like "C:\SomeFolder". What location is this stored on the Docker container?
How do I force the application when running on Docker to use the Host file system instead of Docker's File system?
This is all done by Docker Volumes.
Read more about that in the Docker documentation:
https://docs.docker.com/storage/volumes/
In the application I have hard coded the path as something like "C:\SomeFolder". What location is this stored on the Docker container?
c:\SomeFolder, assuming you have a Windows container. This is the sort of parameter you'd generally set via a command-line option or environment variable, though.
How do I force the application when running on Docker to use the Host file system instead of Docker's File system?
Use the docker run -v option or an equivalent option to mount some directory from the host on that location. Whatever the contents of that directory are on the host will replace what's in the container at startup time, and after that changes in the host should be reflected in the container and vice versa.
If you have an opportunity to rethink this design, there are a number of lurking issues around file ownership and the like. The easiest way to circumvent these issues are to store data somewhere like a database (which may or may not itself be running in Docker) and use network I/O to send data to and from the container, and store as little as possible in the container filesystem. docker run -v is an excellent way to inject configuration files and get log files out in a typical server-oriented use.
I'm trying create a container to run a program. I'm using a pre configurate image and now I need run the program. However, it's a machine learning program and I need a dataset from my computer to run.
The file is too large to be copied to the container. It would be best if the program running in the container searched the dataset in a local directory of my computer, but I don't know how I can do this.
Is there any way to do this reference with some docker command? Or using Dockerfile?
Yes, you can do this. What you are describing is a bind mount. See https://docs.docker.com/storage/bind-mounts/ for documentation on the subject.
For example, if I want to mount a folder from my home directory into /mnt/mydata in a container, I can do:
docker run -v /Users/andy/mydata:/mnt/mydata myimage
Now, /mnt/mydata inside the container will have access to /Users/andy/mydata on my host.
Keep in mind, if you are using Docker for Mac or Docker for Windows there are specific directories on the host that are allowed by default:
If you are using Docker Machine on Mac or Windows, your Docker Engine daemon has only limited access to your macOS or Windows filesystem. Docker Machine tries to auto-share your /Users (macOS) or C:\Users (Windows) directory. So, you can mount files or directories on macOS using.
Update July 2019:
I've updated the documentation link and naming to be correct. These type of mounts are called "bind mounts". The snippet about Docker for Mac or Windows no longer appears in the documentation but it should still apply. I'm not sure why they removed it (my Docker for Mac still has an explicit list of allowed mounting paths on the host).