build .apk files for [unbound](https://nlnetlabs.nl/projects/unbound) with support for as cache backend [redis](https://redis.io) for [alpine linux](https://alpinelinux.org/).
there are two possible options to build a specific version:
1. you can specify the environment variable `VERSION` to build a specific version. if the environment variable is unspecified it will default to `latest`.
2. [download](https://nlnetlabs.nl/downloads/unbound/) an `.zip` or `.tar.gz` archive and put it in the `unbound/src` subfolder **(dont forget to rebuild the image)**.
### docker:
`docker run --rm -it -e VERSION=latest -v .build/:/build <imageid>`