How to mount a host directory in a Docker container

There are a couple ways you can do this. The simplest way to do so is to use the dockerfile ADD command like so:

ADD . /path/inside/docker/container

However, any changes made to this directory on the host after building the dockerfile will not show up in the container. This is because when building a container, docker compresses the directory into a .tar and uploads that context into the container permanently.

The second way to do this is the way you attempted, which is to mount a volume. Due to trying to be as portable as possible you cannot map a host directory to a docker container directory within a dockerfile, because the host directory can change depending on which machine you are running on. To map a host directory to a docker container directory you need to use the -v flag when using docker run, e.g.,:

# Run a container using the `alpine` image, mount the `/tmp`# directory from your host into the `/container/directory`# directory in your container, and run the `ls` command to# show the contents of that directory.docker run \    -v /tmp:/container/directory \    alpine \    ls /container/directory

The user of this question was using Docker version 0.9.1, build 867b2a9, I will give you an answer for docker version >= 17.06.

What you want, keep local directory synchronized within container directory, is accomplished by mounting the volume with type bind. This will bind the source (your system) and the target (at the docker container) directories. It's almost the same as mounting a directory on linux.

According to Docker documentation, the appropriate command to mount is now mount instead of -v. Here's its documentation:

• --mount: Consists of multiple key-value pairs, separated by commas. Each key/value pair takes the form of a <key>=<value> tuple. The --mount syntax is more verbose than -v or --volume, but the order of the keys is not significant, and the value of the flag is easier to understand.

• The type of the mount, which can be bind, volume, or tmpfs. (We are going to use bind)

• The source of the mount. For bind mounts, this is the path to the file or directory on the Docker daemon host. May be specified as source or src.

• The destination takes as its value the path where the file or directory will be mounted in the container. May be specified as destination, dst, or target.

So, to mount the the current directory (source) with /test_container (target) we are going to use:

    docker run -it --mount src="$(pwd)",target=/test_container,type=bind k3_s3

If these mount parameters have spaces you must put quotes around them. When I know they don't, I would use `pwd` instead:

    docker run -it --mount src=`pwd`,target=/test_container,type=bind k3_s3

You will also have to deal with file permission, see this article.

you can use -v option from cli, this facility is not available via Dockerfile

docker run -t -i -v <host_dir>:<container_dir> ubuntu /bin/bash

where host_dir is the directory from host which you want to mount.you don't need to worry about directory of container if it doesn't exist docker will create it.

If you do any changes in host_dir from host machine (under root privilege) it will be visible to container and vice versa.