Network Connectivity Issues from Docker Containers on AWS ipv6-only Lightsail Ubuntu Instance

Hello.

Since the IPv4 address can be confirmed when name resolution is performed within the container, we suspect that the Docker container is not configured for IPv6.
Have you configured it to support IPv6 using the steps in the document below?
https://docs.docker.com/engine/daemon/ipv6/

Hi,

Yes, I have configure Docker for IPv6 following the document:

• My /etc/docker/daemon.json looks like this:

{
  "ipv6": true,
  "fixed-cidr-v6": "2001:db8:1::/64"
}

• I also set enable_ipv6: true inside my docker compose files:

# compose.traefik.yml
name: traefik
services:
  traefik:
    command:
      - --providers.docker=true
      - --providers.docker.exposedbydefault=false
      - --providers.file.directory=/etc/traefik/dynamic_conf
      - --providers.file.watch=true
      - --entrypoints.http.address=:80
      - --entrypoints.https.address=:443
      - --accesslog
      - --log
      - --api
      - --certificatesresolvers.myresolver.acme.tlschallenge=true
      - --certificatesresolvers.myresolver.acme.email=johndoe@example.com
      - --certificatesresolvers.myresolver.acme.storage=/letsencrypt/acme.json
    image: traefik:v2.6
    restart: unless-stopped
    labels:
      traefik.docker.network: traefik-public
      traefik.enable: "true"
      traefik.http.middlewares.https-redirect.redirectscheme.permanent: "true"
      traefik.http.middlewares.https-redirect.redirectscheme.scheme: https
      traefik.http.services.traefik-public.loadbalancer.server.port: "8080"
    networks:
      traefik-public: null
    ports:
      - mode: ingress
        target: 80
        published: "80"
        protocol: tcp
      - mode: ingress
        target: 443
        published: "443"
        protocol: tcp
    volumes:
      - type: bind
        source: /home/ubuntu/traefik/letsencrypt
        target: /letsencrypt
        bind:
          create_host_path: true
      - type: bind
        source: /home/ubuntu/traefik/certificates
        target: /certificates
        bind:
          create_host_path: true
      - type: bind
        source: /var/run/docker.sock
        target: /var/run/docker.sock
        read_only: true
        bind:
          create_host_path: true
      - type: bind
        source: ./traefik.config.yml
        target: /etc/traefik/dynamic_conf/conf.yml
        read_only: true
        bind:
          create_host_path: true
networks:
  traefik-public:
    name: traefik-public
    enable_ipv6: true

# docker-compose.yml
services:
  redis:
    image: redis:alpine
    restart: unless-stopped
    networks:
      bench-network: null
  frappe:
    image: jk1117/bench:erpnext-version-15
    restart: unless-stopped
    command: sleep infinity
    environment:
      - SHELL=/bin/bash
    volumes:
      - bench-dir:/home/frappe/frappe-bench
      - sites:/home/frappe/frappe-bench/sites:rw
      - assets:/home/frappe/frappe-bench/apps:rw
      - templates:/home/frappe/.bench/bench/config/templates:rw
    networks:
      bench-network: null
    extra_hosts:
      - "actual.domain.com:[2406:da1c:31d:2d00:33df:130:e1a2:8478]"
  proxy:
    depends_on:
      frappe:
        condition: service_started
    restart: unless-stopped
    environment:
      BACKEND: frappe:8000
      FRAPPE_SITE_NAME_HEADER: $$host
      SOCKETIO: frappe:443
      UPSTREAM_REAL_IP_ADDRESS: 2406:da1c:31d:2d00:33df:130:e1a2:8478
      UPSTREAM_REAL_IP_HEADER: X-Forwarded-For
      UPSTREAM_REAL_IP_RECURSIVE: "off"
      SERVER_NAME: actual.domain.com
    image: nginx:1.23.1
    labels:
      traefik.docker.network: traefik-public
      traefik.enable: 'true'
      traefik.http.services.uat.loadbalancer.server.port: '8080'
      traefik.http.routers.uat-http.entrypoints: http
      traefik.http.routers.uat-http.rule: Host(`actual.domain.com`)
      traefik.http.routers.uat-http.service: uat
      traefik.http.routers.uat-http.middlewares: https-redirect
      traefik.http.routers.uat-https.rule: Host(`actual.domain.com`)
      traefik.http.routers.uat-https.entrypoints: https
      traefik.http.routers.uat-https.tls: true
      traefik.http.routers.uat-https.service: uat
      traefik.http.routers.uat-https.tls.certresolver: myresolver
    networks:
      traefik-public: null
      bench-network: null
    volumes:
      - ./nginx_templates:/etc/nginx/templates
      - sites:/usr/share/nginx/html/sites:rw
      - assets:/usr/share/nginx/html/assets:ro
      - templates:/usr/share/nginx/html/templates:ro
volumes:
  bench-dir:
  assets:
  sites:
  templates:
networks:
  bench-network:
    enable_ipv6: true
  traefik-public:
    name: traefik-public
    external: true
    enable_ipv6: true
  mariadb-network:
    name: mariadb-network
    external: true
    enable_ipv6: true

• I also verify the setup by running docker run --rm --network ip6net -p 80:80 traefik/whoami and the result is exactly the same as the documentation provided.

Am I missing any setting to enable IPv6 for Docker Compose?