Standarize unbound, prepare for setup inclusion

- Use jinja template for configuration file (start.py)
- Limit access to the Mailu subnet
- Implement health checks

core/unbound/Dockerfile

@@ -1,14 +0,0 @@
-FROM alpine:3.8
-
-RUN apk add --no-cache unbound curl \
-	&& curl -o /etc/unbound/root.hints https://www.internic.net/domain/named.cache \
-	&& chown root:unbound /etc/unbound \
-	&& chmod 775 /etc/unbound \
-	&& apk del --no-cache curl \
-	&& /usr/sbin/unbound-anchor -a /etc/unbound/trusted-key.key | true
-
-COPY unbound.conf /etc/unbound/unbound.conf
-
-EXPOSE 53/udp 53/tcp
-
-CMD /usr/sbin/unbound

core/unbound/unbound.conf

@@ -1,19 +0,0 @@
-server:
-  verbosity: 1
-  interface: 0.0.0.0
-  interface: ::0
-  logfile: /dev/stdout
-  do-ip4: yes
-  do-ip6: yes
-  do-udp: yes
-  do-tcp: yes
-  do-daemonize: no
-  access-control: 0.0.0.0/0 allow
-  directory: "/etc/unbound"
-  username: unbound
-  auto-trust-anchor-file: trusted-key.key
-  root-hints: "/etc/unbound/root.hints"
-  hide-identity: yes
-  hide-version: yes
-  max-udp-size: 4096
-  msg-buffer-size: 65552