"No Such Host", Docker can't access the internet.

[CCWeb]

I first posted this in the general installation forum, but thought maybe it would be better here in the Docker forum.  (MODS, please feel free to edit or move as appropriate.)

I'm new to Docker and Unraid, and I'm using them to set up a home server on a new mini PC. 

Unraid installs and runs well, including Unraid Connect, but I cannot get Docker to connect to the internet.  Via the Unraid app page, I can install Unraid plugins, but have had no success in installing Docker containers.  Each attempt fails with a "No Such Host" error message. (see example below)

Per the troubleshooting guides, I've confirmed internet connectivity and confirmed the desired repositories are on line. The Fix Common Problems app reports no issues.  I've tried every possible network settings change and combination I can find.    I've even tried a fresh clean reinstall of the entire Unraid system to ensure all the defaults are properly reset.  

Any suggestions or ideas would be welcome.

 

Thanks!


______________________

12-21 Update:

I enabled IP6 on my home router, then set my Unraid network to use both IP4 & IP6.  Docker can now pull what it needs from the internet and I've successfully installed 3 of 4 apps so far.  🙂 

I don't know if IP6 was the fix, workaround, or enabled a coincidental reset.  I'll continue to investigate and then test the functionality of my installed Docker apps then report back.

______________________

docker run
  -d
  --name='Home-Assistant-Container'
  --net='bridge'
  --privileged=true
  -e TZ="America/Los_Angeles"
  -e HOST_OS="Unraid"
  -e HOST_HOSTNAME="SVR1"
  -e HOST_CONTAINERNAME="Home-Assistant-Container"
  -l net.unraid.docker.managed=dockerman
  -l net.unraid.docker.webui='http://[IP]:[PORT:8123]'
  -l net.unraid.docker.icon='https://raw.githubusercontent.com/balloob/unraid-docker-templates/master/balloob/home-assistant-icon.png'
  -v '/mnt/user/appdata/Home-Assistant-Container':'/config':'rw' 'ghcr.io/home-assistant/home-assistant:stable'

Unable to find image 'ghcr.io/home-assistant/home-assistant:stable' locally
docker: Error response from daemon: Head "https://ghcr.io/v2/home-assistant/home-assistant/manifests/stable": Get "https://ghcr.io/token?scope=repository%3Ahome-assistant%2Fhome-assistant%3Apull&service=ghcr.io": dial tcp: lookup ghcr.io on 192.168.200.1:53: no such host.
See 'docker run --help'.

The command failed.

 

____________________

 

 

 

 

svr1-diagnostics-20231219-2222.zip

Edited December 21, 2023 by CCWeb
Add more info. Enabling IP6 a workaround?

[dave234ee]

i am also suffering the same problems. fresh install last night everything worked great even installed a few apps jellyfin etc. Today cant get anything to install.

 

ocker run
  -d
  --name='ApacheGuacamole'
  --net='bridge'
  -e TZ="America/Los_Angeles"
  -e HOST_OS="Unraid"
  -e HOST_HOSTNAME="Deep-Cloud"
  -e HOST_CONTAINERNAME="ApacheGuacamole"
  -e 'OPT_MYSQL'='Y'
  -e 'OPT_MYSQL_EXTENSION'='N'
  -e 'OPT_SQLSERVER'='N'
  -e 'OPT_OPENID'='N'
  -e 'OPT_LDAP'='N'
  -e 'OPT_DUO'='N'
  -e 'OPT_CAS'='N'
  -e 'OPT_TOTP'='N'
  -e 'OPT_QUICKCONNECT'='N'
  -e 'OPT_HEADER'='N'
  -e 'OPT_SAML'='N'
  -e 'PUID'='99'
  -e 'PGID'='100'
  -l net.unraid.docker.managed=dockerman
  -l net.unraid.docker.webui='http://[IP]:[PORT:8080]/'
  -l net.unraid.docker.icon='https://i.imgur.com/eflpez4.png'
  -p '8080:8080/tcp'
  -v '/mnt/user/appdata/ApacheGuacamole':'/config':'rw' 'jasonbean/guacamole'
Please wait ......

Unable to find image 'jasonbean/guacamole:latest' locally

deep-cloud-diagnostics-20231221-1128.zip

[CCWeb]

Dec 23rd Update:

Apparently this a DNS settings issue and adding two external public DNS servers in Network Settings fixed the problem. 🙂 

Per Unraid support:

In Unraid Network Settings

(1) Enable Static DNS addresses
(2) Add as #1 DNS: 208.67.222.222
(3) Add as #2 DNS: 208.67.220.220

-------------------
My Previous Workaround:

I don't know if enabling IP6 is a solution, workaround, or it coincidentally resets something, but I enabled IP6 on my router, then selected "IP4 & IP6" in my Unraid network settings.  As of now, it did the trick and Docker can now pull down what it needs from the internet.  🙂 

 

So far I've been able to download and install 3 of 4 Docker apps.  1 still can't find the repository it needs, perhaps this is a problem unique to that container.

I may still have a Docker IP4 routing issue and I'll continue to investigate and confirm the connectivity of the installed apps from Docker, then post an update here.  

 

Thanks!

Edited December 23, 2023 by CCWeb
Added Unraid's suggested solution