I successfully ran a bind-mount for my blog, however I think that a managed volume would be a better choice instead of bind-mount, the question is, if I need to edit the theme through SFTP or vim or simply add some files to the volume, how do I do that? Right now the bind-mount allows me to edit the files, but how would I add/edit files on the volume or if I wanted later to get those files out?
For example: docker volume create --name test-volume
How can I add/edit data there or access via SFTP?
As says the official documentation:
Volumes are stored in a part of the host filesystem which is managed by Docker (/var/lib/docker/volumes/ on Linux). Non-Docker processes should not modify this part of the filesystem.
So the idea is to set up a new container, that bind the working directory as well as mounts a volume, and then manage files in them.
For example, lets say your working dir is /app:
docker run \
-v $PROJECT:/tmp/project
-v test-volume:/app \
alpine \
/bin/sh -c "cp /tmp/project/* /app"
Sync tools can be used, like here.
To manage data of your volume through container itself via SFTP, you need to make sure that image you are using supports SSH connections and map a 22 port, more info you could find here.
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
I've searched a while on the internet for a solution.
My setup is as following:
I have a php-apache docker image (basically apache with PHP support). I used a named volume to store the webroot (all Web files, most common PHP files).
This is working fine so far, I can see my files in the browser.
Because it's a multi user project (multiple devs) I want that multiple users should be able to edit the webroot.
The named volume can be edited under /var/lib/docker/volumes/apache_webroot. But it needs root access and that is not a good practice.
How could I manage the permission to this volume without using root? I tought about creating a container that just mounts the named volume and then forwards it to a path where I have access to with all users? Or can I somehow change the permission of /var/lib/docker/volumes/apache_webroot
Anyone ran into the same situation? Should I just mount it to a path on the host machine and not use named volumes at all?
An alternative would be to create a container for each user and bind them to this volume (docker containers support shared volumes). That would be a particularly good idea.
docker run -d --name some_users_container --volume my_webroot_shared_volume_name /bin/bash -c "while true; do sleep 10; done"
Then all you gotta do is to have the other users ssh to the remote docker container.
I have a situation where:
I want to mount a directory ~/tmp/mycode to /mycode readonly
I want to be able to edit the files in the directory, so I can't just run -v /my/local/path/tmp/mycode:/mycode
I want it to not persist changes on the host filesystem though so I can't mount it read/write
~/tmp/mycode is rather large
Basically I want to be able to edit the files in the mounted volume but not have those changes persisted.
My current workflow is to create a dummy container using a dockerfile:
ADD . /mycode
and then execute that container.
However as the repository grows, this step takes longer and longer to perform, because the only way I can think is to make a complete copy of ~/tmp/mycode in order to be able to manipulate the files in the container.
I've also thought about mounting the directory and copying it inside the container and committing that container, but that has the same issue.
Is there a way to run a docker container to allow file edits without persisting them on the host short of copying the whole directory?
I am using the latest docker for mac, currently Version 17.03.1-ce-mac5 (16048).
This is fairly trivial to do with docker and overlay:
docker run --name myenv --privileged -v /my/local/path/tmp/mycode:/mnt/rocode:ro -it ubuntu /bin/bash
docker exec -d myenv /sbin/mount -t overlay overlay -o lowerdir=/mnt/rocode,upperdir=/mycode,workdir=/mnt/code-workdir /mycode
This should mount the code from your directory read only and create the overlay inside the container so that /mnt/rocode is read only, but /mycode is writable.
Make sure that your kernel is 3.18+ and that you have overlay in your /proc/filesystems.
I am trying to capture the state of a docker container as an image, in a way that includes files I have added to a volume within the container. So, if I run the original container in this way:
$ docker run -ti -v /cookbook ubuntu:14.04 /bin/bash
root#b78f3599d936:/# cd cookbook
root#b78f3599d936:/cookbook# touch foo.txt
Now, if I either export, or commit the container as a new docker image, and then run a container from the new image, then the file, foo.txt is never included in the /cookbook directory.
My question is whether there is a way to create an image from a container in a way that allows the image to include file content within its volumes.
whether there is a way to create an image from a container in a way that allows the image to include file content within its volumes?
No, because volume is designed to manage data inside and between your Docker containers, it's used to persist and share data. What's in image is usually your program(artifacts, executables, libs. e.g) with its whole environment, building/updating data to image does not make much sense.
And in docs of volumes, they told us:
Changes to a data volume will not be included when you update an image.
Also in docs of docker commit:
The commit operation will not include any data contained in volumes mounted inside the container.
Well, by putting the changes in a volume, you're excluding them from the actual container. The documentation for docker export includes this:
The docker export command does not export the contents of volumes associated with the container. If a volume is mounted on top of an existing directory in the container, docker export will export the contents of the underlying directory, not the contents of the volume.
Refer to Backup, restore, or migrate data volumes in the user guide for examples on exporting data in a volume.
This points to this documentation. Please follow the steps there to export the information stored in the volume.
You're probably looking for something like this:
docker run --rm --volumes-from <containerId> -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /cookbook
This would create a file backup.tar with the contents of the container's /cookbook directory and store it in the current directory of the host. You could then use this tar file to import it in another container.
Essentially, there are three ways to do persistence in Docker:
You can keep files in a volume, which is a filesystem managed by Docker. This is what happens in your example: because the /cookbook directory is part of a volume, your file does not get commited/exported with the image. It does however get stored in the volume, so if you remount the same volume in a different container, you will find your file there. You can list your volumes using docker volume ls. As you can see, you should probably give your volumes names if you plan to reuse them. You can mount an existing volume, or create a new one, if the name does not exist, with
docker run -v name:/directory ubuntu
You can keep files as part of the image. If you commit the container, all changes to its file hierarchy are stored in the new image except those made to mounted volumes. So if you just get rid of the -v flag, your file shows up in the commit.
You can bind mount a directory from the host machine to the container, by using the -v /hostdir:/targetdir syntax. The container then simply has access to a directory of the host machine.
Docker commit allows you to create an image from a container and its data (mounted volumes will be ignored)
My docker-compose has a data container which isn't mapped to a local directory in the host machine, and I want to change it from:
volumes:
- /var/www/html
to
volumes:
- /html:/var/www/html
But when I will restart the container, it will remove the current data container and replace it with a new one.
I know that the container is actually still there, but is there an easy way to do it without the creation of a new data container.
My docker-compose version is 1.7.1 (under boot2docker).
Thanks.
Try at your own risk:
create your host directory /htmlas you wish
docker inspect {container_name} | grep Source and grab your volume path on the host system. It'll be something like /var/lib/docker/volumes/abdb15a2eff[...]/_data
copy the content of that directory to your host directory
recreate the container as you wish.
One safe way to do this is to create a backup of the data from inside the Docker image. Then restore that backup to the directory on your host machine. The Docker Volumes Tutorial mentions a process like this near the bottom.
Here's how you'd do it:
First, mount a directory from your host machine into the container if you don't already have one mounted in. Maybe a volume like ./:/backup. Next, run a backup command like this:
docker-compose run service-name tar czvf /backup/html_data.tar.gz /var/www/html
Now you have html_data.tar.gz in your current directory. Extract it wherever you want and be on your way!
(I'm assuming, based on the way you indicated your volumes, that you're using docker-compose. The process is similar for vanilla Docker.)
Alternate approach, with --volumes-from
Get the name (or hash) of the container with the data you want to copy. You can do this with docker ps. For this example, let's call it container1. Now run this command to back up its data:
docker run --rm --volumes-from container1 -v $(pwd):/backup ubuntu:latest tar czvf /backup/html_data.tar.gz /var/www/html
Note that the image you use (ubuntu:latest) is not important as long as it can tar things.