go-container

README

go-container

Build your own container with golang. This container requires docker with cgroup v2.

Feature

• container with new PID, UTS, NAMESPACE
• cgroups v2
• pivot_root jail

Run

git clone git@github.com:go-zen-chu/go-container.git && cd go-container
make download-alpine
GOARCH=amd64 GOOS=linux go build ./main.go

# this binary only supports running on linux
docker run -it --privileged --rm -v $PWD:/go-container -w /go-container alpine:latest /bin/sh

/go-container # ./main run /bin/sh
...
2020/03/22 06:32:08 running given command on container: [/bin/sh]
/ # ls
bin     home    mnt     putold  sbin    tmp                      
dev     lib     opt     root    srv     usr                      
etc     media   proc    run     sys     var

Description

Please refer to my blog post -> (Japanese)Go言語で自分好みのコンテナを作成する - Think Abstract

FAQ

cannot build go binary on my Mac

When you go run main.go on MacOS, you'll get error as below.

# github.com/containerd/cgroups
../../go/pkg/mod/github.com/containerd/cgroups@v0.0.0-20200226104544-44306b6a1d46/memory.go:211:33: undefined: unix.SYS_EVENTFD2
../../go/pkg/mod/github.com/containerd/cgroups@v0.0.0-20200226104544-44306b6a1d46/memory.go:211:55: undefined: unix.EFD_CLOEXEC
../../go/pkg/mod/github.com/containerd/cgroups@v0.0.0-20200226104544-44306b6a1d46/utils.go:67:8: undefined: unix.CGROUP2_SUPER_MAGIC
../../go/pkg/mod/github.com/containerd/cgroups@v0.0.0-20200226104544-44306b6a1d46/utils.go:74:18: undefined: unix.CGROUP2_SUPER_MAGIC

This is because cgroups uses Linux kernel function. Build with GOARCH=amd64 GOOS=linux go build

cgroup v2 memory limit is not working

This is known issue and I'm investigating it. May be running go-container in docker or containerd container is not suitable for testing cgroup v2 limits because they don't run systemd (cgroup v2 works well with systemd).

I'm getting operation not permitted when running in lima

When you run container in lima & contianerd, you may get error above when mounting /proc. I'm keep investigating but yet catches a cause. Please use docker.

License