docker-compose.yml

services:
  redis:
    image: redis:7.0.8-alpine
    container_name: unbound-redis
    command: redis-server --save 43200 1 7200 100 --loglevel warning --rdbchecksum no 
    volumes:
      - "./redis:/data"
    restart: always

  unbound:
    image: crazymax/unbound
    container_name: unbound
    depends_on:
      - redis
    ports:
      - target: 5053
        published: 8553
        protocol: tcp
      - target: 5053
        published: 8553
        protocol: udp
    volumes:
      - "./config:/config:ro"
    restart: always

cachedb.conf in /config

cachedb:
  backend: "redis"
  secret-seed: "default"
  redis-server-host: redis
  redis-server-port: 6379

forward-records.conf in /config

forward-zone:
  name: "."
  forward-tls-upstream: yes
 
  # Quad9(Standard)
  forward-addr: 9.9.9.9@853#dns.quad9.net
  forward-addr: 149.112.112.112@853#dns.quad9.net
  #forward-addr: 2620:fe::10@853#dns11.quad9.net
  #forward-addr: 2620:fe::fe:10@853#dns11.quad9.net
  
  # OpenDNS
  forward-addr: 208.67.222.222@853#doh.opendns.com
  forward-addr: 208.67.220.220@853#doh.opendns.com
  #forward-addr: 2620:119:35::35@853#doh.opendns.com
  #forward-addr: 2620:119:53::53@853#doh.opendns.com
  
  # Cloudflare
  forward-addr: 1.1.1.1@853#cloudflare-dns.com
  forward-addr: 1.0.0.1@853#cloudflare-dns.com
  #forward-addr: 2606:4700:4700::1111@853#cloudflare-dns.com
  #forward-addr: 2606:4700:4700::1001@853#cloudflare-dns.com
  
  # Google
  forward-addr: 8.8.8.8@853#dns.google
  forward-addr: 8.8.4.4@853#dns.google
  #forward-addr: 2001:4860:4860::8888@853#dns.google
  #forward-addr: 2001:4860:4860::8844@853#dns.google

Check dbsize docker exec -it unbound-redis redis-cli dbsize

Check all dbs docker exec -it unbound-redis redis-cli INFO | grep ^db

Thanks to https://github.com/crazy-max/docker-unbound