# Docker Build Clone using Elixir
[](https://travis-ci.org/esl/ex_docker_build)
[](https://coveralls.io/github/esl/ex_docker_build)
## What's the special thing about this?
This comes with support for **Bind Mounts at Build Time**
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `ex_docker_build` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:ex_docker_build, "~> 0.6.2"}
]
end
```
Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at [https://hexdocs.pm/ex_docker_build](https://hexdocs.pm/ex_docker_build).
## Usage
### Example 1 - **Elixir Release with Distillery**
Clone the following example in a directory you wish
```sh
$> mkdir ~/workspace
$> cd workspace
$> git clone https://github.com/sescobb27/elixir-docker-guide
```
Start a mix session with `iex -S mix` and type the following instructions
```ex
path = Path.expand("~/workspace/elixir-docker-guide")
{:ok, image_id} = Path.join([path, "Dockerfile"]) |>
ExDockerBuild.DockerfileParser.parse_file!() |>
ExDockerBuild.DockerBuild.build(path)
```
Or you can start using escript:
```ex
mix escript.build
Generated escript ex_docker_build
```
Then call the escript passing the path to a Dockerfile
```ex
./ex_docker_build ~/workspace/elixir-docker-guide/Dockerfile
[info] image created d44264c48dad
```
Copy the image_id into your clipboard and run the image with docker like this
```sh
docker run d44264c48dad # d44264c48dad being the image_id
```
### Example 2 - **Docker Build with Bind Mount**
in `test/fixtures/Dockerfile_bind.dockerfile` in line 2 `VOLUME /Users/kiro/test:/data`
change `/Users/kiro/test` with your path of preference e.g `/Your/User/test`
(must be an absolute path, relative paths aren't supported yet)
```sh
$> mkdir ~/test
```
```ex
path = Path.expand("./test/fixtures")
{:ok, image_id} = Path.join([path, "Dockerfile_bind.dockerfile"]) |>
ExDockerBuild.DockerfileParser.parse_file!() |>
ExDockerBuild.DockerBuild.build(path)
```
Then if you run `ls ~/test` you should see a file named `myfile.txt` with
`hello world!!!` as content
## Environment and debugging
This library respects the environmental variable `DOCKER_HOST` this can be
very helpful when debugging, for example:
In on terminal run `socat` :
```
socat -v UNIX-LISTEN:/tmp/fake,fork UNIX-CONNECT:/var/run/docker.sock
```
In the terminal where you are running `ex_docker_build` set the docker socket :
```
export DOCKER_HOST=unix:///tmp/fake
```
Now you can observe all interactions with the Docker API server.
## Limitations
- Doesn't support relative paths in the container when `COPY`ing
- `COPY ./relative/path/to/origin:/absolute/path/to/destination`
- Doesn't support standard `VOLUMES`, it only supports the following `VOLUME`s type
with custom syntax
- [Bind Mounts](https://docs.docker.com/storage/bind-mounts/) e.g `VOLUME ~/path/to/host/dir:/path/to/container/dir`
- [Named Volumes](https://docs.docker.com/storage/volumes/) e.g `VOLUME volume_name` and then using it like `VOLUME volume_name:/path/to/container/dir`
## TODO:
- [ ] add support for more docker file instructions
- [ ] resolve TODOs inside the source code
