How to mount a host directory in a Docker containe

Question

I am trying to mount a host directory into a Docker container so that any updates done on the host is reflected into the Docker containers. I couldn't succeed after googling and reading the Docker volume links.

Where am I doing something wrong. Here is what I did:

kishore$ cat Dockerfile


FROM ubuntu:trusty
RUN apt-get update
RUN apt-get -y install git curl vim
CMD ["/bin/bash"]
WORKDIR /test_container
VOLUME ["/test_container"]

kishore$ tree
.
├── Dockerfile
└── main_folder
    ├── tfile1.txt
    ├── tfile2.txt
    ├── tfile3.txt
    └── tfile4.txt


1 directory, 5 files
kishore$ pwd
/Users/kishore/tdock

kishore$ docker build --tag=k3_s3:latest .


Uploading context 7.168 kB
Uploading context
Step 0 : FROM ubuntu:trusty
 ---> 99ec81b80c55
Step 1 : RUN apt-get update
 ---> Using cache
 ---> 1c7282005040
Step 2 : RUN apt-get -y install git curl vim
 ---> Using cache
 ---> aed48634e300
Step 3 : CMD ["/bin/bash"]
 ---> Running in d081b576878d
 ---> 65db8df48595
Step 4 : WORKDIR /test_container
 ---> Running in 5b8d2ccd719d
 ---> 250369b30e1f
Step 5 : VOLUME ["/test_container"]
 ---> Running in 72ca332d9809
 ---> 163deb2b1bc5
Successfully built 163deb2b1bc5
Removing intermediate container b8bfcb071441
Removing intermediate container d081b576878d
Removing intermediate container 5b8d2ccd719d
Removing intermediate container 72ca332d9809


kishore$ docker run -d -v /Users/kishore/main_folder:/test_container k3_s3:latest
c9f9a7e09c54ee1c2cc966f15c963b4af320b5203b8c46689033c1ab8872a0ea

kishore$ docker run -i -t k3_s3:latest /bin/bash


root@0f17e2313a46:/test_container# ls -al
total 8
drwx------  2 root root 4096 Apr 29 05:15 .
drwxr-xr-x 66 root root 4096 Apr 29 05:15 ..


root@0f17e2313a46:/test_container# exit
exit

kishore$ docker -v
Docker version 0.9.1, build 867b2a9

• I don't know how to check boot2docker version

Questions, issues facing:

1. How do I need to link the main_folder to the test_container folder present inside the docker container?
2. I need to make this automatically. How do I to do that without really using the run -d -v command?
3. What happens if the boot2docker crashes? Where are the Docker files stored (apart from Dockerfile)?

Answer 1

Jul 2015 update - boot2docker now supports direct mounting. You can use -v /var/logs/on/host:/var/logs/in/container directly from your Mac prompt, without double mounting

Answer 2

Note that in Windows you'll have to provide the absolute path.

• Host: Windows 10
• Container: Tensorflow Notebook

Below worked for me.

docker run -t -i -v D:/projects/:/home/chankeypathak/work -p 8888:8888 jupyter/tensorflow-notebook /bin/bash

Answer 3

i had same issues , i was trying to mount C:\Users\ folder on docker
this is how i did it Docker Toolbox command line

 $ docker run -it --name <containername> -v /c/Users:/myVolData <imagename>

Answer 4

I'm just experimenting with getting my SailsJS app running inside a Docker container to keep my physical machine clean.

I'm using the following command to mount my SailsJS/NodeJS application under /app:

cd my_source_code_folder
docker run -it -p 1337:1337 -v $(pwd):/app my_docker/image_with_nodejs_etc

Answer 5

boot2docker together with VirtualBox Guest Additions
How to mount /Users into boot2docker

https://medium.com/boot2docker-lightweight-linux-for-docker/boot2docker-together-with-virtualbox-guest-additions-da1e3ab2465c

tl;dr Build your own custom boot2docker.iso with VirtualBox Guest Additions (see link) or download http://static.dockerfiles.io/boot2docker-v1.0.1-virtualbox-guest-additions-v4.3.12.iso and save it to ~/.boot2docker/boot2docker.iso.

Answer 6

Is it possible that you use docker on OS X via boot2docker or something similar.

I've made the same experience - the command is correct but nothing (sensible) is mounted in the container, anyway.

As it turns out - it's already explained in the docker documentation. When you type docker run -v /var/logs/on/host:/var/logs/in/container ... then /var/logs/on/host is actually mapped from the boot2docker VM-image, not your Mac.

You'll have to pipe the shared folder through your VM to your actual host (the Mac in my case).