Duckdns container fails to connect to duckdns

[Tommy]

I’m using Docker/Portainer on Debian 12 and attempting to use a subdomain on duckdns to point back to the server.

The container log indicates that something is not working correctly:

Detecting IPv4 via DuckDNS
curl: (7) Failed to connect to www.duckdns.org port 443 after 9280 ms: Couldn’t connect to server
Something went wrong, please check your settings Fri Jan 19 09:56:24 EST 2024
The response returned was:
Detecting IPv4 via DuckDNS
curl: (7) Failed to connect to www.duckdns.org port 443 after 9259 ms: Couldn’t connect to server
Something went wrong, please check your settings Fri Jan 19 10:01:50 EST 2024
The response returned was:

the .yaml is below:

---

version: “2.1”
services:
duckdns:
image: linuxserver/duckdns
container_name: duckdns
environment:
- PUID=1001 #optional
- PGID=100 #optional
- TZ=US/Eastern
- SUBDOMAINS=<my subdomain (not including .duckdns.org)>
- TOKEN=
- LOG_FILE=false #optional
restart: unless-stopped
volumes:
- /duckdns/config:/config #optional

What am I missing here?

[aptalca]

One of three possibilties:

1. duckdns had an outage and was not accessible at the time
2. container has no internet connection
3. something on your network is blocking access to it (pihole, adguard, etc.)

[Tommy]

Thank you for your help!

I have an older duckdns container running on a RasPi on the same network that is working correctly, so I think that rules out 1.

I added “network-host”, and can ping google.com from container’s console, so I think that takes care of 2 and 3. Correct? I’m not running Adguard or pihole, etc…

new stack from Portainer:

version: “2.1”
services:
duckdns:
image: linuxserver/duckdns
network_mode: “host”
container_name: duckdns

environment:
  - PUID=1000 #optional
  - PGID=1000 #optional
  - TZ=US/Eastern
  - SUBDOMAINS=<redacted>
  - TOKEN=<redacted>
  - LOG_FILE=false #optional
restart: unless-stopped
volumes:
  - /duckdns/config:/config #optional

Log from the container remained as above…

[aptalca]

why not ping that duckdns address?
you should not need host networking

[Tommy]

I could ping google, but for some reason duckdns remains unreachable from within the container and on the host.
Since I can ping duckdns from other machines on my network, I suspect the problem is NOT related to the duckdns or the container.

Thank you for your help!

[Tommy]

The default gateway on my server was incorrect.