Docker Volume Plugin for Juicefs

Modified from https://github.com/vieux/docker-volume-sshfs

Usage

docker plugin install juicedata/juicefs

# JuiceFS open sourced version
docker volume create -d juicedata/juicefs:latest -o name=$JFS_VOL -o metaurl=$JFS_META_URL -o access-key=$JFS_ACCESSKEY -o secret-key=JFS_SECRETKEY jfsvolume
docker run -it -v jfsvolume:/opt busybox ls /opt

# JuiceFS hosted version
docker volume create -d juicedata/juicefs:latest -o name=$JFS_VOL -o token=$JFS_TOKEN -o accesskey=$JFS_ACCESSKEY -o secretkey=$JFS_SECRETKEY jfsvolume
docker run -it -v jfsvolume:/opt busybox ls /opt

Development

Boot up vagrant environment

vagrant up
vagrant ssh

Inside vagrant

export WORKDIR=~/go/src/docker-volume-juicefs
mkdir -p $WORKDIR
rsync -avz --exclude plugin --exclude .git --exclude .vagrant /vagrant/ $WORKDIR/
cd $WORKDIR
make
make enable
docker volume create -d juicedata/juicefs:next -o name=$JFS_VOL -o token=$JFS_TOKEN -o accesskey=$JFS_ACCESSKEY -o secretkey=$JFS_SECRETKEY jfsvolume
docker run -it -v jfsvolume:/opt busybox ls /opt

Docker swarm

Install juicedata/juicefs plugin on every worker node, otherwise service mounting JuiceFS volume will not be scheduled.

Use docker service to deploy to Docker swarm

docker service create --name nginx --mount \
type=volume,volume-driver=juicedata/juicefs,source=jfsvolume,destination=/jfs,\
volume-opt=name=$JFS_VOL,volume-opt=token=$JFS_TOKEN,volume-opt=accesskey=$JFS_ACCESSKEY,volume-opt=secretkey=$JFS_SECRETKEY nginx:alpine

Scale up

docker service scale nginx=3

Deployment from docker compose file is not supported because there is no way to pass volume options.

Debug

Enable debug information

docker plugin disable juicedata/juicefs:latest
docker plugin set juicedata/juicefs:latest DEBUG=1
docker plugin enable juicedata/juicefs:latest

To quickly test out HEAD version:

docker plugin disable juicedata/juicefs:latest
CC=/usr/bin/musl-gcc go build -o bin/docker-volume-juicefs --ldflags '-linkmode external -extldflags "-static"' .
mv bin/docker-volume-juicefs /var/lib/docker/plugins/3dea603741f58726d65b273d095f2bc01d1a1c8954a5498f5592041df8cdcd6c/rootfs
docker plugin enable juicedata/juicefs:latest

The stdout of the plugin is redirected to dockerd log. The entries have a plugin=<ID> suffix.

runc, the default docker container runtime can be used to collect juicefs log

# runc --root /run/docker/plugins/runtime-root/plugins.moby list
ID                                                                 PID         STATUS      BUNDLE
452d2c0cf3fd45e73a93a2f2b00d03ed28dd2bc0c58669cca9d4039e8866f99f   3672        running     /run/docker/containerd/...

# runc --root /run/docker/plugins/runtime-root/plugins.moby exec 452d2c0cf3fd45e73a93a2f2b00d03ed28dd2bc0c58669cca9d4039e8866f99f cat /var/log/juicefs.log
umount: can't unmount /jfs/volumes/ci-aliyun: Invalid argument
Unable to connect to local syslog daemon
2018/05/07 13:56:19.752864 <INFO>: Cache dir: /var/jfsCache/ci-aliyun limit: 1024 MB
2018/05/07 13:56:19.756331 <INFO>: Found 0 cached blocks (0 bytes)
2018/05/07 13:56:20.913240 <INFO>: mount successfully, st_dev: 48

NOTE: the directory for plugin runtime could be moby-plugins in some version of Docker.