droot

droot

Droot is a super-easy container tool to chroot a docker image without docker.

Overview

Docker has a powerful concept about an application deployment process, that is Build, Ship, Run. But there are many cases that docker runtime is beyond our current capabilities.

Droot provides a simpler container runtime without annoying Linux Namespaces. Droot depends on traditional Linux functions such as chroot(2), Linux capabilities(7) and a bind mount. droot helps you to chroot a container image built by docker and to import/export container images on Amazon S3.

Requirements

• Docker (droot push only depends on it)
• Linux (droot run and droot umount only supports it)

Installation

Homebrew

$ brew tap yuuki1/droot
$ brew install droot

Download binary from GitHub Releases

Releases・yuuki1/droot - GitHub

Build from source

 $ go get github.com/yuuki1/droot
 $ go install github.com/yuuki1/droot/cmd

Usage

$ droot push --to s3://drootexamples/app.tar.gz dockerfiles/app

$ droot pull --dest /var/containers/app --src s3://drootexamples/app.tar.gz

$ sudo droot run --bind /var/log/ --root /var/containers/app command

$ sudo droot umount --root /var/containers/app

$ sudo droot rm --root /var/containers/app

How to set your AWS credentials

Droot push/pull subcommands support the following methods to set your AWS credentials.

• an IAM instance profile. http://docs.aws.amazon.com/codedeploy/latest/userguide/how-to-create-iam-instance-profile.html
• Environment variables.

$ export AWS_ACCESS_KEY_ID=********
$ export AWS_SECRET_ACCESS_KEY=********
$ export AWS_REGION=********

• ~/.aws/credentials a standard to manage credentials in the AWS SDKs

How to set docker endpoint

Droot push supports the environment variables same as docker-machine such as DOCKER_HOST, DOCKER_TLS_VERIFY, DOCKER_CERT_PATH. ex.

DOCKER_TLS_VERIFY=1
DOCKER_HOST=tcp://192.168.x.x:2376
DOCKER_CERT_PATH=/home/yuuki/.docker/machine/machines/dev

Roodmap

• rmi command to clean a image on S3
• pull command with the rsync option
• push/pull other compression algorithms
• image versioning
• pull from docker registry
• drivers except Amazon S3
• run reads .docekrenv, .dockerinit
• reduce fork&exec
• push/pull S3 download/upload part-size options

Development

Droot uses a library with cgo, so it is necessary to build in Linux for a Linux binary. It is recommanded to use Docker for development if you are on OSX and other OSs.

build in Docker container

$ ./script/build_in_container.sh

Release

$ vim ./cmd/version.go
$ ./script/build_in_container.sh cross
$ ghr -u yuuki1 -p 2 $VERSION snapshot/

Contribution

1. Fork (https://github.com/yuuki1/droot/fork)
2. Create a feature branch
3. Commit your changes
4. Rebase your local changes against the master branch
5. Run test suite with the make test command and confirm that it passes
6. Create a new Pull Request

Author

y_uuki