How to mount a host directory in a Docker container

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   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  --- gt  99ec81b80c55 Step 1   RUN apt-get update  --- gt  Using cache  --- gt  1c7282005040 Step 2   RUN apt-get -y install git curl vim  --- gt  Using cache  --- gt  aed48634e300 Step 3   CMD    bin bash    --- gt  Running in d081b576878d  --- gt  65db8df48595 Step 4   WORKDIR  test container  --- gt  Running in 5b8d2ccd719d  --- gt  250369b30e1f Step 5   VOLUME    test container    --- gt  Running in 72ca332d9809  --- gt  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 c9f9a7e09c54ee1c2cc966f15c963b4af320b5203b8c46689033c1ab8872a0eakishore  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 exitkishore  docker -v Docker version 0 9 1  build 867b2a9   I don t know how to check boot2docker version   Questions  issues facing    How do I need to link the main folder to the test container folder present inside the docker container  I need to make this automatically  How do I to do that without really using the run -d -v command  What happens if the boot2docker crashes  Where are the Docker files stored  apart from Dockerfile

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As of Docker 18-CE  you can use docker run -v  src path  container path to do 2-way binding of a host folder   There is a major catch here though if you re working with Windows 10 WSL and have Docker-CE for Windows as your host and then docker-ce client tools in WSL  WSL knows about the entire   filesystem while your Windows host only knows about your drives  Inside WSL  you can use  mnt c projectpath  but if you try to docker run -v   PWD   projectpath  you will find in the host that  projectpath  is empty because on the host  mnt means nothing   If you work from  c projectpath though and THEN do docker run -v   PWD   projectpath and you WILL find that in the container   projectpath will reflect  c projectpath in realtime  There are no errors or any other ways to detect this issue other than seeing empty mounts inside your guest   You must also be sure to  share the drive  in the Docker for Windows settings

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I ve been having the same issue  My command line looked like this   docker run --rm -i --name  NAME -v  pwd   sources z  NAME   The problem was with  pwd   So I changed that to   pwd    docker run --rm -i --name  NAME -v   pwd   sources z  NAME

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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

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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  lt key gt   lt value gt  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

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On Mac OS  to mount a folder  Users  lt name gt  projects  on your mac at the root of your container   docker run -it -v  Users  lt name gt  projects   projects  lt container name gt  bash  ls  projects

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To get this working in Windows 10 I had to open the Docker Settings window from the system tray and go to the Shared Drives section   I then checked the box next to C  Docker asked for my desktop credentials to gain authorisation to write to my Users folder   Then I ran the docker container following examples above and also the example on that settings page  attaching to  data in the container    docker run -v c  Users  lt user name gt  Desktop dockerStorage  data -other -options

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I had the same requirement to mount host directory from container and I used volume mount command  But during testing noticed that it s creating files inside container too but after some digging found that they are just symbolic links and actual file system used form host machine

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2 successive mounts  I guess many posts here might be using two boot2docker  the reason you don t see anything is that you are mounting a directory from boot2docker  not from your host   You basically need 2 successive mounts      the first one to mount a directory from your host to your system        the second to mount the new directory from boot2docker to your container like this     1  Mount local system on boot2docker  sudo mount -t vboxsf hostfolder  boot2dockerfolder  2  Mount boot2docker file on linux container   docker run -v  boot2dockerfolder  root containerfolder -i -t imagename    Then when you ls inside the containerfolder you will see the content of your hostfolder

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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

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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

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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

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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

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Using command-line   docker run -it --name  lt WHATEVER gt  -p  lt LOCAL PORT gt   lt CONTAINER PORT gt  -v  lt LOCAL PATH gt   lt CONTAINER PATH gt  -d  lt IMAGE gt   lt TAG gt   Using docker-compose yaml   version   2    services      cms         image   lt IMAGE gt   lt TAG gt         ports         -  lt LOCAL PORT gt   lt CONTAINER PORT gt         volumes         -  lt LOCAL PATH gt   lt CONTAINER PATH gt   Assume    IMAGE  k3 s3 TAG  latest LOCAL PORT  8080 CONTAINER PORT  8080 LOCAL PATH   volume-to-mount CONTAINER PATH   mnt  Examples    First create  volume-to-mount   Skip if exist     mkdir -p  volume-to-mount   docker-compose -f docker-compose yaml up -d  version   2    services      cms         image  ghost-cms latest        ports         - 8080 8080        volumes         -  volume-to-mount  mnt   Verify your container    docker exec -it CONTAINER ID ls -la  mnt

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docker run -v  host directory  container directory -t IMAGE-NAME  bin bash  docker run -v  root shareData  home shareData -t kylemanna openvpn  bin bash   In my system I ve corrected the answer from nhjk  it works flawless when you add the -t flag

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How do I link the main folder to the test container folder present inside the docker container   Your command below is correct  unless your on a mac using boot2docker depending on future updates  in which case you may find the folder empty  See mattes answer for a tutorial on correcting this   docker run -d -v  Users kishore main folder  test container k3 s3 latest   I need to make this run automatically  how to do that without really using the run -d -v command   You can t really get away from using these commands  they are intrinsic to the way docker works  You would be best off putting them into a shell script to save you writing them out repeatedly    What happens if boot2docker crashes  Where are the docker files stored   If you manage to use the -v arg and reference your host machine then the files will be safe on your host   If you ve used  docker build -t myimage    with a Dockerfile then your files will be baked into the image   Your docker images  i believe  are stored in the boot2docker-vm  I found this out when my images disappeared when i delete the vm from VirtualBox   Note  i don t know how Virtualbox works  so the images might be still hidden somewhere else  just not visible to docker

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If the host is windows 10 then instead of forward slash  use backward slash -  docker run -it -p 12001 80 -v c  Users C Desktop dockerStorage  root sketches   Make sure the host drive is shared  C in this case   In my case I got a prompt asking for share permission after running the command above

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I found that any directory laying under system directive like  var   usr   etc could not be mount under the container   The directive should be at user s space -v switch instructs docker daemon to mount local directory to the container  for example   docker run -t -d -v   local   path    container   path  --name  container name   imagename

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Here s an example with a Windows path   docker run -P -it --name organizr --mount src   c Users MyUserName AppData Roaming DockerConfigs Organizr  dst  config type bind organizrtools organizr-v2 latest   As a side note  during all of this hair pulling  having to wrestle with figuring out  and retyping paths over and over and over again  I decided to whip up a small AutoHotkey script to convert a Windows path to a  Docker Windows  formatted path  This way all I have to do is copy any Windows path that I want to use as a mount point to the clipboard  press the  Apps Key  on the keyboard  and it ll format it into a path format that Docker appreciates   For example   Copy this to your clipboard   C  Users My PC AppData Roaming DockerConfigs Organizr  press the Apps Key while the cursor is where you want it on the command-line  and it ll paste this there     c Users My PC AppData Roaming DockerConfigs Organizr   Saves a lot to time for me  Here it is for anyone else who may find it useful     --------------------------------------------------------------------------------------------------------------     Docker Utility  Convert a Windows Formatted Path to a Docker Formatter Path                     Useful for  example  when mounting Windows volumes via the command-line      By        J  Scott Elblein   Version   1 0   Date      2 5 2019     Usage     Cut or Copy the Windows formatted path to the clipboard  press the AppsKey on your keyboard              usually right next to the Windows Key   it ll format it into a  docker path  and enter it             into the active window  Easy example usage would be to copy your intended volume path via             Explorer  place the cursor after the  -v  in your Docker command  press the Apps Key and             then it ll place the formatted path onto the line for you      TODO      I may or may not add anything to this depending on needs  Some ideas are                           - Add a tray menu with the ability to do some things  like just replace the unformatted path                 on the clipboard with the formatted one rather than enter it automatically              - Add  smarter  handling so the it first confirms that the clipboard text is even a path in                 the first place   would need to be able to handle Win   Mac   Linux              - Add command-line handling so the script doesn t need to always be in the tray  you could                 just pass the Windows path to the script  have it format it  then paste and close                  Also  could have it just check for a path on the clipboard upon script startup  if found                 do it s job  then exit the script              - Add an  all-in-one  action  to copy the selected Windows path  and then output the result              - Whatever else comes to mind      --------------------------------------------------------------------------------------------------------------   NoEnv SendMode Input SetWorkingDir  A ScriptDir   AppsKey          Create a new var  store the current clipboard contents  should be a Windows path      NewStr    Clipboard        Rip out the first 2 chars  should be a drive letter and colon   amp  convert the letter to lowercase       NOTE  I could probably replace the following 3 lines with a regexreplace  but atm I m lazy and in a rush      tmpVar    SubStr NewStr  1  2      StringLower  tmpVar  tmpVar        Replace the uppercase drive letter and colon with the lowercase drive letter and colon     NewStr    StrReplace NewStr  SubStr NewStr  1  2   tmpVar         Replace backslashes with forward slashes     NewStr    StrReplace NewStr                    Replace all colons with nothing     NewStr    StrReplace NewStr                  Remove the last char if it s a trailing forward slash     NewStr     RegExReplace NewStr               Append a leading forward slash if not already there     if RegExMatch NewStr           0         NewStr           NewStr        If there are any spaces in the path     wrap in double quotes     if RegExMatch NewStr        gt  0         NewStr            NewStr               Send the result to the active window     SendInput   NewStr

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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

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You can also do this with Portainer web application for a different visual experience   First pull the Portainer image   docker pull portainer portainer   Then create a volume for Portainer   docker volume create portainer data   Also create a Portainer container   docker run -d -p 8000 8000 -p 9000 9000 --name portainer --restart always -v  var run docker sock  var run docker sock -v portainer data  data portainer portainer   You will be able to access the web app with your browser at this URL   http   localhost 9000   At the first login  you will be prompted to set your Portainer admin credentials   In the web app  follow these menus and buttons   Container   Add container   Fill settings   Deploy Container   I had trouble to create a  mount  volume with Portainer and I realized I had to click  bind  when creating my container s volume  Below is an illustration of the volume binding settings that worked for my container creation with a mounted volume binded to the host     P S   I m using Docker 19 035 and Portainer 1 23 1

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you can use -v option from cli  this facility is not available via Dockerfile  docker run -t -i -v  lt host dir gt   lt container dir gt   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

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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  lt containername gt  -v  c Users  myVolData  lt imagename gt

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For Windows 10 users  it is important to have the mount point inside the C  Users  directory  I tried for hours to get this to work  This post helped but it was not obvious at first as the solution for Windows 10 is a comment to an accepted answer  This is how I did it   docker run -it -p 12001 80 -v   c Users C Desktop dockerStorage  root sketches    lt your-image-here gt   bin bash   Then to test it  you can do echo TEST  gt  hostTest txt inside your image  You should be able to see this new file in the local host folder at C  Users C Desktop dockerStorage

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UPDATE  As of  June 2017  Docker for Mac takes care of all the annoying parts of this where you have to mess with VirtualBox  It lets you map basically everything on your local host using the  private prefix  More info here    UPDATE   All the current answers talk about Boot2docker  Since that s now deprecated in favor of docker-machine  this works for docker-machine   First  ssh into the docker-machine vm and create the folder we ll be mapping to   docker-machine ssh  MACHINE NAME  sudo mkdir -p    VOL DIR      Now share the folder to VirtualBox   WORKDIR   basename   VOL DIR   vboxmanage sharedfolder add   MACHINE NAME  --name   WORKDIR  --hostpath   VOL DIR  --transient   Finally  ssh into the docker-machine again and mount the folder we just shared   docker-machine ssh  MACHINE NAME  sudo mount -t vboxsf -o uid    U   gid    G      WORKDIR      VOL DIR      Note  for UID and GID you can basically use whatever integers as long as they re not already taken   This is tested as of docker-machine 0 4 1 and docker 1 8 3 on OS X El Capitan

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Had the same problem  Found this in the docker documentation       Note  The host directory is  by its nature  host-dependent  For this reason  you can   t mount a host directory from Dockerfile  the VOLUME instruction does not support passing a host-dir  because built images should be portable  A host directory wouldn   t be available on all potential hosts    So  mounting a read write host directory is only possible with the -v parameter in the docker run command  as the other answers point out correctly

[docker] How to mount a host directory in a Docker container

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