i am using native docker for mac and i have a small application running with docker container .
currently i am manually copying the data from my mac to docker container using docker cp command.
i want to make it dynamic, i want to put the data in my local directory which should get sync with docker container .
example:
mac local dir : users/vishnu/data/
which should get sync to
`<Docker-container-ID>:/opt/deploy/`
the container is already running ,i should not release the running container . i can only stop and start . is there a way ?? Thanks in advance
host mounted volume.
when you docker run you add a -v /Users/vishnu/data:/opt/deploy parameters.
if you need to add a mounted volume to your existing container, use the Kitematic UI. it's easier that way. but in general, you should add this when you docker run.
...
also, FYI - the idea that you can't delete a container is an anti-pattern with Docker. if you can't delete your container, because it would cause too many problems, you're doing something wrong. https://derickbailey.com/2017/04/05/what-i-learned-by-deleting-all-of-my-docker-images-and-containers/
Related
I need to work with all the files from a docker container, my approach is to copy all the list of files from the container to my host.
I'm using the next docker commands, for example with the postgres image:
docker create -ti --name dummy_1 postgres bash
docker cp dummy_1:/. Documents/docker/dockerOne
With this I have all the container folders and files in my host.
And then the idea is to transverse all the files with the java API, and work with them and finally delete the files and folders from local, but I would like to know if is it a better approach, maybe with Java and access directly to the container files, instead of create a local copy of the container files in my host.
Any ideas?
You can build a small server app inside your docker container which feeds you the information you need at an exposed port. Thats how i would have done it.
Maybe I don't understand the question, but you can mount a volume when you run, not create the container
docker run -v /host/path:/container/path your_container
Any code in the container (e.g. Java) that modifies files at /container/path will be reflected on the host, and not need to be copied back in/out. Similarly, any modifications on the host filesystem will be seen in the container.
I don't think I can implement an API in the docker container
Yes you can. You bind a TCP port using -p flag
Similar question: mac image path
In mac, when I run docker inspect containerID
I see most of the stuff is coming from /var/lib/docker/
however, this path neither exists in the host (mac) nor the docker container.
where is this path refer to?
you can find your files in container:path and use the docker commands to copy them to your local machine and vice versa (I'm assuming you are trying to move files e.g. from your local machine to your container). I had the same exact issue you mentioned but I manage to move files with
docker cp local_path containerID:target_path
to see your container_ID simply run docker ps -a, it should show it even if unmounted.
See https://docs.docker.com/engine/reference/commandline/cp/
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
I have a Docker container running on my Mac. This Docker container has a home folder like:
/home/my_user/my_project/
It is based on a Ubuntu OS image and running on my Mac. When I run this container, the container constantly updates a folder under the my_project folder. Now when I stop and remove this container, it just gets erased and when I start a new instance of the container, the process has to begin all over again, i.e., the container starts writing into the my_project folder, but the old files which it already wrote is completely lost.
How can I make the data written by the container be persistent even after a container delete / restart?
Docker persistent volumes is what I understand that I need, but how can I mount a local folder on my Mac such that the data is written and persisted? This container could run on a Windows machine, so how can I make a persistent volume across different OS?
You need to start your container with the -v flag. So if you were to mount the /home/my_user/my_project directory from the container onto the host to /srv/my_app/data for example, you'd need to use it as follows:
docker run -v /srv/my_app/data:/home/my_user/my_project IMAGE_NAME
There's also a difference between volumes and bind mounts, which I explained here
I'm running a docker container with a volume /var/my_folder. The data there is persistent: When I close the container it is still there.
But also want to have the data available on my host, because I want to work on code with an IDE, which is not installed in my container.
So how can I have a folder /var/my_folder on my host machine which is also available in my container?
I'm working on Linux Mint.
I appreciate your help.
Thanks. :)
Link : Manage data in containers
The basic run command you want is ...
docker run -dt --name containerName -v /path/on/host:/path/in/container
The problem is that mounting the volume will, (for your purposes), overwrite the volume in the container
the best way to overcome this is to create the files (inside the container) that you want to share AFTER mounting.
The ENTRYPOINT command is executed on docker run. Therefore, if your files are generated as part of your entrypoint script AND not as part of your build THEN they will be available from the host machine once mounted.
The solution is therefore, to run the commands that creates the files in the ENTRYPOINT script.
Failing this, during the build copy the files to another directory and then COPY them back in your ENTRYPOINT script.