How to ADD all files/directories except a hidden directory like .git in Dockerfile

One of things we do often is to package all source code in Dockerfile when we build a Docker image.

ADD . /app

How can we avoid including the .git directory in simple way ?

I tried the Unix way of handling this using ADD [^.]* /app/

Complete sample:

docker@boot2docker:/mnt/sda1/tmp/abc$ find .
.
./c
./.git
./Dockerfile
./good
./good/a1
docker@boot2docker:/mnt/sda1/tmp/abc$ cat Dockerfile
FROM ubuntu

ADD [^.]* /app/
docker@boot2docker:/mnt/sda1/tmp/abc$ docker build -t abc .
Sending build context to Docker daemon 4.096 kB
Sending build context to Docker daemon
Step 0 : FROM ubuntu
---> 04c5d3b7b065
Step 1 : ADD [^.]* /app/
d ---> 5d67603f108b
Removing intermediate container 60159dee6ac8
Successfully built 5d67603f108b
docker@boot2docker:/mnt/sda1/tmp/abc$ docker run -it abc
root@1b1705dd66a2:/# ls -l app
total 4
-rw-r--r-- 1 1000 staff 30 Jan 22 01:18 Dockerfile
-rw-r--r-- 1 root root   0 Jan 22 01:03 a1
-rw-r--r-- 1 root root   0 Jan 22 00:10 c

And secondly, it will lose the directory structure, since good\a1 gets changed to a1.

Related source code in Docker is https://github.com/docker/docker/blob/eaecf741f0e00a09782d5bcf16159cc8ea258b67/builder/internals.go#L115

You may exclude unwanted files with the help of the .dockerignore file

> How can we avoid including the .git directory in simple way ?

Just create a file called .dockerignore in the root context folder with the following lines

**/.git
**/node_modules

With such lines Docker will exclude directories .git and node_modules from any subdirectory including root. Docker also supports a special wildcard string ** that matches any number of directories (including zero).

> And secondly, it will lose the directory structure, since good\a1 gets changed to a1

With .dockerignore it won't

$ docker run -it --rm sample tree /opt/
/opt/
├── Dockerfile
├── c
│   └── no_sslv2.patch
└── good
    └── a1
        └── README

3 directories, 3 files

Reference to official docs: .dockerignore

Add .dockerignore file in your root directory (syntax like the .gitignore file)