Unbound-Recursive

Simple Docker image for Unbound as recursive DNS resolver with DNSSEC.

This is heavily based on mvance/unbound, all credit to them.

This is simply for personal use to have a more up-to-date version of Unbound.

As at your own risk, i provide no support at all.

NEWS: There is now a Alpine-based image available under the :alpine image tag. So far it has been working without problems for myself. It will stay under that dedicated tag for a while and if there are no issues, it becomes the new default and the outdated and much larger Debian build becomes optional.

Image is available at:

• Docker Hub: docker.io/l33tlamer/unbound-recursive:latest

• Github: ghcr.io/l33tlamer/unbound-recursive:latest

Available tags:

• latest equals 1.25.1

• 1.25.1 Unbound v1.25.1 with OpenSSL v3.6.2 (Debian Bookworm)

• alpine Unbound v1.25.1 with OpenSSL v3.6.2 (Alpine 3.24)

• 1.24.1 Unbound v1.24.1 with OpenSSL v3.6.0 (Debian Bookworm)

• 1.24.0 Unbound v1.24.0 with OpenSSL v3.6.0 (Debian Bookworm)

Currently for amd64 only, maybe arm later.

unbound -V output:

Version 1.25.1

Configure line: --disable-dependency-tracking --prefix=/opt/unbound --with-pthreads --with-username=_unbound --with-ssl=/opt/openssl --with-libevent --with-libnghttp2 --enable-dnstap --enable-tfo-server --enable-tfo-client --enable-event-api --enable-subnet
Linked libs: libevent 2.1.12-stable (it uses epoll), OpenSSL 3.6.2 7 Apr 2026
Linked modules: dns64 subnetcache respip validator iterator
TCP Fastopen feature available

Note: The image will check if /opt/unbound/etc/unbound/unbound.conf exists, and if it doesnt, it will create a config by copying from /opt/unbound/etc/unbound/default.conf.

If you want to use your own custom config, i suggest you use a bind mount at container runtime:

-v /your/own/unbound.conf:/opt/unbound/etc/unbound/unbound.conf

You should also take a look at optional performance tuning:

For example: Number of threads and slabs, size of rr_cache_size and msg_cache_size.

Image source is available at:

• https://github.com/l33tlamer/unbound-recursive

Example Docker Compose setup to use this with Pihole can be found here:

• https://github.com/l33tlamer/pihole-unbound

Enjoy.