Nginx Proxy Manager – Error “Temporary failure in name resolution” when requesting certificate

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1

Hi everyone,

I’m trying to issue a Let’s Encrypt certificate in Nginx Proxy Manager (Docker setup), but I keep getting DNS resolution errors.

Here’s the relevant log output:

[Date/Time] [SSL ] › ℹ info Requesting Let'sEncrypt certificates
[Date/Time] [SSL ] › ℹ info Command: certbot certonly --config '/etc/letsencrypt.ini' --work-dir "/tmp/letsencrypt-lib" --logs-dir "/tmp/letsencrypt-log" --cert-name "npm-test" --agree-tos --authenticator webroot --preferred-challenges "dns,http" --domains "mydomain.example.com"

[Date/Time] [Express ] › ⚠ warning Saving debug log to /tmp/letsencrypt-log/letsencrypt.log
An unexpected error occurred:
requests.exceptions.ConnectionError: HTTPSConnectionPool(host='acme-v02.api.letsencrypt.org', port=443): Max retries exceeded with url: /directory (Caused by NameResolutionError("<urllib3.connection.HTTPSConnection object>: Failed to resolve 'acme-v02.api.letsencrypt.org' ([Errno -3] Temporary failure in name resolution)"))

So far I’ve tried:

  • Adding DNS servers (1.1.1.1, 8.8.8.8) in my docker-compose.yml.
  • Restarting the container and Docker.
  • Verified that my domain points to the correct public IP.

Still getting the same EAI_AGAIN error.

Environment:

  • Nginx Proxy Manager (jc21/nginx-proxy-manager:latest)
  • Running via docker-compose
  • Host: Ubuntu (systemd-resolved is enabled)
  • Ports 80/443 are open

My domain is: proxy.gibert.cc
My web server is:
Nginx Proxy Manager (jc21/nginx-proxy-manager:latest, running Nginx inside the container).

The operating system my web server runs on is:
Ubuntu Linux (latest updates installed).

My hosting provider, if applicable, is:
Netcup

I can login to a root shell on my machine:
Yes.

I'm using a control panel to manage my site:
Yes, Nginx Proxy Manager (latest Docker image) and Portainer.

The version of my client is:
Certbot 2.10.0 (shipped inside the Nginx Proxy Manager container).

2

That's nothing to do with Let's Encrypt. Your local DNS resolver is not working properly. You are best to take that up with the NPM support forum.

4 Likes
3

Ok. Thank!

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4

This usually solves it, together with restarting the docker daemon.

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