etcd-fs

etcd-fs

Use etcd as a filesystem

THis IS STILL WORK IN PROGRESS

Why using etcd as a fileystem?

Because filesystem API is super stable, widely known and supported, and very simple.

Also because it seems like this can be useful for lots of companies out there that have already deployed apps that read some configuration file from local filesystem and would love to load these configuration files to something like etcd and ensure a consistent view of across a cluster of nodes.

How does it work?

Etcd-fs uses go-fuse and go-etcd, two nice modules to create fuse filesystem in go and use etcd from go.

Every file maps to a key in etcd. Every directory maps to a directory in etcd. The content of every file maps to the value of the key in etcd.

When you mount the filesystem, it will mount the root directory of etcd.

How do I install it?

go get -u github.com/derlaft/etcd-fs

This generates an executable file etcdfs in $GOPATH/bin/. You can mount etcd as a filesystem by running etcdfs MOUNT_PATH ETCD_ENDPOINT. For example:

etcds /tmp/foobar http://localhost:4001

Then you can access /tmp/foobar and use etcd as a filesystem.

To unmount it:

fusermount -u /tmp/foobar

To run tests:

• Run a etcd node: docker run --rm -p 8001:8001 -p 4001:4001 quay.io/coreos/etcd:v2.3.0 -advertise-client-urls=http://0.0.0.0:4001 -listen-client-urls=http://0.0.0.0:4001
• Run tests: go test -v

What is supported?

Basic filesystem operations like:

• Reading/Writing files
• Creating/Deleting files
• Creating/Deleting directories

What is missing?

• Lots of optimizations
• Lots of error handling
• Specifiying more options to etcd connection
• Mount filesystem to some node in etcd, not necessarily the root
• Use watch to get updates from etcd and maybe change file modification time (????)