DNS resolution fails on debian 12.8.0 in a VM

[LexiconCode]

DNS resolution fails/misconfigured when running ansible-playbook main.yml . Specifically, the error message indicates a failure to resolve the hostname registry-1.docker.io due to a connection issue with the DNS server running on localhost (::1 refers to the IPv6 loopback address):

in TASK [Ensure internet-monitoring environment is running.
dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:55381->[::1]:53: read: connection refused

Full Error

root@net:~/internet-pi# ansible-playbook main.yml

... 

TASK [Ensure internet-monitoring directory is not a Git repository.] ********************************************************
ok: [127.0.0.1]

TASK [Copy templated internet-monitoring files into place.] *****************************************************************
ok: [127.0.0.1] => (item={'src': 'docker-compose.yml.j2', 'dest': 'docker-compose.yml'})
ok: [127.0.0.1] => (item={'src': 'grafana-config.monitoring.j2', 'dest': 'grafana/config.monitoring'})
ok: [127.0.0.1] => (item={'src': 'prometheus.yml.j2', 'dest': 'prometheus/prometheus.yml'})
ok: [127.0.0.1] => (item={'src': 'prometheus-pinghosts.yaml.j2', 'dest': 'prometheus/pinghosts.yaml'})

TASK [Ensure internet-monitoring environment is running.] *******************************************************************
fatal: [127.0.0.1]: FAILED! => {"actions": [{"id": "ping", "status": "Pulling", "what": "image"}, {"id": "speedtest", "status": "Pulling", "what": "image"}, {"id": "nodeexp", "status": "Pulling", "what": "image"}, {"id": "prometheus", "status": "Pulling", "what": "image"}, {"id": "grafana", "status": "Pulling", "what": "image"}], "changed": false, "cmd": "/usr/bin/docker compose --ansi never --progress json --project-directory /root/internet-monitoring up --detach --no-color --quiet-pull --no-build --", "containers": [], "images": [], "msg": "Error when processing ping: Get \"https://registry-1.docker.io/v2/\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701->[::1]:53: read: connection refused\nError when processing grafana: context canceled\nError when processing nodeexp: context canceled\nError when processing prometheus: context canceled\nError when processing speedtest: context canceled\nGeneral error: Error response from daemon: Get \"https://registry-1.docker.io/v2/\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701->[::1]:53: read: connection refused", "rc": 18, "stderr": "{\"id\":\"ping\",\"text\":\"Pulling\"}\n{\"id\":\"speedtest\",\"text\":\"Pulling\"}\n{\"id\":\"nodeexp\",\"text\":\"Pulling\"}\n{\"id\":\"prometheus\",\"text\":\"Pulling\"}\n{\"id\":\"grafana\",\"text\":\"Pulling\"}\n{\"id\":\"ping\",\"text\":\"Error\",\"status\":\"Get \\\"https://registry-1.docker.io/v2/\\\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701-\\u003e[::1]:53: read: connection refused\"}\n{\"id\":\"grafana\",\"text\":\"Error\",\"status\":\"context canceled\"}\n{\"id\":\"nodeexp\",\"text\":\"Error\",\"status\":\"context canceled\"}\n{\"id\":\"prometheus\",\"text\":\"Error\",\"status\":\"context canceled\"}\n{\"id\":\"speedtest\",\"text\":\"Error\",\"status\":\"context canceled\"}\n{\"error\":true,\"message\":\"Error response from daemon: Get \\\"https://registry-1.docker.io/v2/\\\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701-\\u003e[::1]:53: read: connection refused\"}\n", "stderr_lines": ["{\"id\":\"ping\",\"text\":\"Pulling\"}", "{\"id\":\"speedtest\",\"text\":\"Pulling\"}", "{\"id\":\"nodeexp\",\"text\":\"Pulling\"}", "{\"id\":\"prometheus\",\"text\":\"Pulling\"}", "{\"id\":\"grafana\",\"text\":\"Pulling\"}", "{\"id\":\"ping\",\"text\":\"Error\",\"status\":\"Get \\\"https://registry-1.docker.io/v2/\\\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701-\\u003e[::1]:53: read: connection refused\"}", "{\"id\":\"grafana\",\"text\":\"Error\",\"status\":\"context canceled\"}", "{\"id\":\"nodeexp\",\"text\":\"Error\",\"status\":\"context canceled\"}", "{\"id\":\"prometheus\",\"text\":\"Error\",\"status\":\"context canceled\"}", "{\"id\":\"speedtest\",\"text\":\"Error\",\"status\":\"context canceled\"}", "{\"error\":true,\"message\":\"Error response from daemon: Get \\\"https://registry-1.docker.io/v2/\\\": dial tcp: lookup registry-1.docker.io on [::1]:53: read udp [::1]:58701-\\u003e[::1]:53: read: connection refused\"}"], "stdout": "", "stdout_lines": []}

PLAY RECAP ******************************************************************************************************************
127.0.0.1                  : ok=10   changed=1    unreachable=0    failed=1    skipped=8    rescued=0    ignored=0

• modified inventory.ini

[internet_pi]
#10.0.100.52 ansible_user=pi

# Comment out the previous line and uncomment this to run inside Raspberry Pi.
127.0.0.1 ansible_connection=local ansible_user=pi

• config.yml
  unmodified but for change-this-password

Troubleshooting

• nslookup registry-1.docker.io

root@net:~/internet-pi# nslookup registry-1.docker.io
;; communications error to ::1#53: connection refused
;; communications error to ::1#53: connection refused
;; communications error to ::1#53: connection refused
;; communications error to 127.0.0.1#53: connection refused
;; no servers could be reached

Temp solution

1. Update /etc/resolv.conf:
   sudo nano /etc/resolv.conf

2. Add or update lines to:

nameserver 8.8.8.8
nameserver 8.8.4.4

3. restart docker
   sudo systemctl restart docker

[sarhatabaot]

This does seem to fix the issue. Thanks for this, spent ~2 hours trying to figure this out.

[LexiconCode]

This does seem to fix the issue. Thanks for this, spent ~2 hours trying to figure this out.

Did you have the same issue with IPv6 or IPv4?