Upgrading to Edge
An upgrade of Alpine Linux from a stable version to the rolling development version, edge can be done in a few simple steps.

 Warning: Edge is under constant development so be careful using it in production. It can break your system.
- Add the edge repository to /etc/apk/repositories: 
echo http://dl-3.alpinelinux.org/alpine/edge/main >> /etc/apk/repositories
or just edit the file in-place (replace v2.2 with your release)sed -i -e 's/v2.2/edge/g' /etc/apk/repositories
 - Upgrade all packages in one shot 
apk upgrade -a -U
 - Check your current release 
cat /etc/alpine-release
You will see the build date attached to the release.