How to edit Docker container files from the host

Question

Now that I found a way to expose host files to the container  -v option  I would like to do kind of the opposite    How can I edit files from a running container with a host editor   sshfs could probably do the job but since a running container is already some kind of host directory I wonder if there is a portable  between aufs  btrfs and device mapper  way to do that

User · Accepted Answer

Whilst it is possible  and the other answers explain how  you should avoid editing files in the Union File System if you can   Your definition of volumes isn t quite right - it s more about bypassing the Union File System than exposing files on the host  For example  if I do     docker run --name  test  -v  volume-test debian echo  test    The directory  volume-test inside the container will not be part of the Union File System and instead will exist somewhere on the host  I haven t specified where on the host  as I may not care - I m not exposing host files  just creating a directory that is shareable between containers and the host  You can find out exactly where it is on the host with     docker inspect -f     Volumes    test map  volume test  var lib docker vfs dir b7fff1922e25f0df949e650dfa885dbc304d9d213f703250cf5857446d104895    If you really need to just make a quick edit to a file to test something  either use docker exec to get a shell in the container and edit directly  or use docker cp to copy the file out  edit on the host and copy back in

User · Answer

The best way is       docker cp CONTAINER FILEPATH LOCALFILEPATH     vi LOCALFILEPATH     docker cp LOCALFILEPATH CONTAINER FILEPATH   Limitations with   docker exec  it can only attach to a running container   Limitations with   docker run  it will create a new container

User · Answer

We can use another way to edit files inside working containers  this won t work if container is stoped     Logic is to  - copy file from container to host - edit file on host using its host editor - copy file back to container  We can do all this steps manualy  but i have written simple bash script to make this easy by one call    bin dmcedit      bin sh set -e  CONTAINER  1 FILEPATH  2 BASE   basename  FILEPATH  DIR   dirname  FILEPATH  TMPDIR  tmp m docker   date   s    mkdir  TMPDIR cd  TMPDIR docker cp  CONTAINER  FILEPATH    DIR mcedit    FILEPATH docker cp    FILEPATH  CONTAINER  FILEPATH rm -rf  TMPDIR  echo  END  exit 1    Usage example      dmcedit CONTAINERNAME  path to file in container   The script is very easy  but it s working fine for me   Any suggestions are appreciated

User · Answer

If you think your volume is a  network drive   it will be easier  To edit the file located in this drive  you just need to turn on another machine and connect to this network drive  then edit the file like normal   How to do that purely with docker  without FTP SSH         Run a container that has an editor  VI  Emacs   Search Docker hub for  alpine vim    Example    docker run -d --name shared vim editor    -v  lt your volume gt   home developer workspace   jare vim-bundle latest    Run the interactive command     docker exec -it -u root shared vim editor  bin bash   Hope this helps

User · Answer

The following worked for me  docker run -it IMAGE NAME  bin bash  eg  my image was called ipython notebook  docker run -it ipython notebook  bin bash

User · Answer

docker run -it -name YOUR NAME IMAGE ID  bin bash    gt vi path to file

User · Answer

I use sftp plugin from my IDE    Install ssh server for your container and allow root access  Run your docker container with -p localport 22 Install from your IDE a sftp plugin   Example using sublime sftp plugin  https   www youtube com watch v HMfjt YMru0

User · Answer

There are two ways to mount files into your container   It looks like you want a bind mount  Bind Mounts This mounts local files directly into the container s filesystem   The containerside path and the hostside path both point to the same file   Edits made from either side will show up on both sides   mount the file     echo foo  gt    foo   docker run --mount type bind source   pwd  foo target  foo -it debian latest   cat  foo foo   local file shows up in container   in a separate shell  edit the file     echo  bar   gt    foo   make a hostside change   back in the container     cat  foo bar   the hostside change shows up   echo baz  gt   foo   make a containerside change   exit     cat foo baz   the containerside change shows up  Volume Mounts  mount the volume    docker run --mount type volume source foovolume target  foo  -it debian latest root containerB  echo  this is in a volume   gt   foo data   the local filesystem is unchanged docker sees a new volume     docker volume ls DRIVER    VOLUME NAME local     foovolume   create a new container with the same volume    docker run --mount type volume source foovolume target  foo  -it debian latest root containerC    cat  foo data this is in a volume   data is still available  syntax  -v vs --mount These do the same thing   -v is more concise  --mount is more explicit  bind mounts -v  hostside path  containerside path --mount type bind source  hostside path target  containerside path  volume mounts -v  containerside path -v volumename  containerside path --mount type volume source volumename target  containerside path   If a volume name is not specified  a random one is chosen   The documentaion tries to convince you to use one thing in favor of another instead of just telling you how it works  which is confusing

User · Answer

The way I am doing is using Emacs with docker package installed  I would recommend Spacemacs version of Emacs  I would follow the following steps   1  Install Emacs  Instruction  and install Spacemacs  Instruction   2  Add docker in your  spacemacs file  3  Start Emacs  4  Find file  SPC f f  and type  docker  lt container-id gt    lt path of dir file in the container gt   5  Now your emacs will use the container environment to edit the files

User · Answer

Here s the script I use      bin bash IFS    n t  set -euox pipefail   CNAME   1  FILE PATH   2   TMPFILE    mktemp   docker exec   CNAME  cat   FILE PATH   gt    TMPFILE   EDITOR   TMPFILE  cat   TMPFILE    docker exec -i   CNAME  sh -c  cat  gt     FILE PATH  rm   TMPFILE    and the gist for when I fix it but forget to update this answer  https   gist github com dmohs b50ea4302b62ebfc4f308a20d3de4213

[docker] How to edit Docker container files from the host?

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