[Help] Unhealthy : Unable to resolve host

[karnalta]

Hello,

I using DDNS-Updater with Cloudflare and it's working nicely. Great tool !

But, it's always unhealthy.

At first it was failling to the fact that it was resolving mail.mydomain.com as the local IP instead of the real external IP. I had a static DNS entry in my firewall to help resolve the domains inside my LAN. I did't really understand why it was an issue as DDNS is using external website to resolve domain's IP, right ?

So, I removed the static entry from my firewall but now it still fail with the following error :

ERROR program is unhealthy: lookup mail.mydomain.com: no such host

nslookup and/or external tools, resolve it correctly.

Here is my config file :

{
  "settings": [
    {
      "provider": "cloudflare",
      "zone_identifier": "xxxxxxxxxxxxxxxxxxxxxxxxx",
      "domain": "mydomain.com",
      "host": "@, mail",
      "ttl": 600,
      "token": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
      "ip_version": "ipv4",
      "ipv6_suffix": ""
    }
  ]
}

I certainly do something wrong..

Thank for your help.

[qdm12]

Are you running it as a binary program or in a docker container?

Is your Cloudflare domain proxied or not?

Have you tried setting the resolver address for example to 1.1.1.1? (see the readme on how to do it with a flag or environment variable).

did't really understand why it was an issue as DDNS is using external website to resolve domain's IP, right ?

Your public ip address is found using 3rd party websites such as ipinfo.io. Your domain name is resolved via DNS to get the dns record ip address, in order to check the public ip address and the dns record match or not.

[karnalta]

It's running in a docker container.

None of my DNS record are proxied at Cloudflare.

I just tried to specify a resolver but still have the error. Here is my docker-compose file content :

version: '3.8'

services:

  app:

    image: 'qmcgaw/ddns-updater'

    container_name: 'ddns-updater'

    restart: always

    ports:

      - '8000:8000'

    volumes:

      - ./data:/updater/data

    environment:

      - UPDATE_COOLDOWN_PERIOD=15m

      - RESOLVER_ADDRESS=1.1.1.1:53

If I nslookup "mail.mydomain.com" from the docker host, it correctly resolve my WAN IP and correspond with ipinfo.io.

I don't understand why DNS resolver work with the main domain but not with a mail subdomain.

[qdm12]

Try adding the docker-compose.yml option dns: 1.1.1.1 to the container and check it works. It would be useful if you can share some logs too.
This is a DNS error where the dns server responds mail.mydomain.com doesn't exist. Can you also double check with https://mxtoolbox.com/DnsLookup.aspx that your domain resolve? Maybe you local dns resolves it but it's not available outside your network.

[karnalta]

Yes, mxtoolbox work fine with mail.mydomain.com.

Tried with DNS 1.1.1.1 in docker-compose but no luck.

Here is a container logs, it look pretty clean. Is there logs somewhere else ?

_Running version latest built on 2024-04-01T13:55:55.861Z (commit ae2bcd5)

🔧 Need help? https://github.com/qdm12/ddns-updater/discussions/new
🐛 Bug? https://github.com/qdm12/ddns-updater/issues/new
✨ New feature? https://github.com/qdm12/ddns-updater/issues/new
☕ Discussion? https://github.com/qdm12/ddns-updater/discussions/new
💻 Email? quentin.mcgaw@gmail.com
💰 Help me? https://www.paypal.me/qmcgaw https://github.com/sponsors/qdm12
2024-04-30T09:50:28Z INFO Settings summary:
├── HTTP client
| └── Timeout: 10s
├── Update
| ├── Period: 5m0s
| └── Cooldown: 15m0s
├── Public IP fetching
| ├── HTTP enabled: yes
| ├── HTTP IP providers
| | └── all
| ├── HTTP IPv4 providers
| | └── all
| ├── HTTP IPv6 providers
| | └── all
| ├── DNS enabled: yes
| ├── DNS timeout: 3s
| └── DNS over TLS providers
| └── all
├── Resolver
| ├── Address: 1.1.1.1:53
| └── Timeout: 5s
├── Server
| ├── Listening address: :8000
| └── Root URL: /
├── Health
| └── Server listening address: 127.0.0.1:9999
├── Paths
| └── Data directory: /updater/data
├── Backup: disabled
└── Logger
├── Level: info
└── Caller: hidden
2024-04-30T09:50:28Z INFO reading JSON config from file /updater/data/config.json
2024-04-30T09:50:28Z INFO Found 2 settings to update records
2024-04-30T09:50:28Z INFO Reading history from database: domain mydomain.com host @ ipv4
2024-04-30T09:50:28Z INFO Reading history from database: domain mydomain.com host mail ipv4
2024-04-30T09:50:28Z INFO [backup] disabled
2024-04-30T09:50:28Z INFO [healthcheck server] listening on 127.0.0.1:9999
2024-04-30T09:50:28Z INFO [http server] listening on :8000_

[karnalta]

I just updated my docker image today and issue is gone.

Did you pushed a fix for it or is it just luck ?

[qdm12]

Luck!