Yet another Docker symlink question. I have a bunch of files that I want to copy over to all my Docker builds. My dir structure is:
parent_dir
- common_files
- file.txt
- dir1
- Dockerfile
- symlink -> ../common_files
In above example, I want file.txt to be copied over when I docker build inside dir1. But I don't want to maintain multiple copies of file.txt. Per this link, as of docker version 0.10, docker build must
Follow symlinks inside container's root for ADD build instructions.
But I get no such file or directory when I build with either of these lines in my Dockerfile:
ADD symlink /path/dirname
or
ADD symlink/file.txt /path/file.txt
mount option will NOT solve it for me (cross platform...).
I tried tar -czh . | docker build -t
without success.
Is there a way to make Docker follow the symlink and copy the common_files/file.txt into the built container?
That is not possible and will not be implemented. Please have a look at the discussion on github issue #1676:
We do not allow this because it's not repeatable. A symlink on your machine is the not the same as my machine and the same Dockerfile would produce two different results. Also having symlinks to /etc/paasswd would cause issues because it would link the host files and not your local files.
For anyone else with this problem, please see this link. Personally I opted for the "build a common base image" solution and it works brilliantly.
One possibility is to run the build in the parent directory, with:
$ docker build [tags...] -f dir1/Dockerfile .
(Or equivalently, in child directory,)
$ docker build [tags...] -f Dockerfile ..
The Dockerfile will have to be configured to do copy/add with appropriate paths. Depending on your setup, you might want a .dockerignore
in the parent to leave out
things you don't want to be put into the context.
instead of using simlinks it is possible to solve problem administratively by just moving files from sites_available to sites_enabled instead of copying or making simlinks
so your site config will be in one copy only in site_available folder if it stopped or something or in sites_enabled if it should be used
来源:https://stackoverflow.com/questions/31881904/docker-follow-symlink-outside-context