Running Windows-based containers I am unable to access the internet from within. Example:
From my host machine I can run the following command:
PS C:\Developer> nslookup aka.ms
Server: cache100.ns.tdc.net
Address: 193.162.153.164
Non-authoritative answer:
Name: aka.ms
Address: 88.221.62.148
When I try to do this from inside a container:
PS C:\Developer> docker run mcr.microsoft.com/dotnet/framework/runtime:4.8-windowsservercore-ltsc2019 powershell nslookup aka.ms
*** UnKnown can't find aka.ms: Server failed
Server: UnKnown
Address: 172.28.112.1
While I am not specifically interested in aka.ms, this error happens for all services I try to connect to, so I am not able to install external libraries, etc.
I am running Docker Desktop v19.03.12. The behaviour occurs regardless of whether I have WSL 2 enabled or not, and my Docker setup is all defaults.
Note: I have some time ago experienced this behaviour. Back then I added the following snippet to my Dockerfile:
RUN powershell -command certutil -generateSSTFromWU roots.sst && certutil -addstore -f root roots.sst && del roots.sst
To my understanding this would install an SSH certificate, which solved the issue. This command, however, now fails:
PS C:\> certutil -generateSSTFromWU roots.sst
The server name or address could not be resolved 0x80072ee7 (WinHttp: 12007 ERROR_WINHTTP_NAME_NOT_RESOLVED) -- http://ctldl.windowsupdate.com/msdownload/update/v3/static/truste
dr/en/authrootstl.cab
CertUtil: -generateSSTFromWU command FAILED: 0x80072ee7 (WinHttp: 12007 ERROR_WINHTTP_NAME_NOT_RESOLVED)
CertUtil: The server name or address could not be resolved
I tested this out on a basic server core image and I got it worked with adding DNS settings.
I connected to the container interactively to test this, but you can probably add the command to a DockerFile too.
docker run -it container powershell
Type netsh to start network configuration
First we look up the network we want to change
( in my case "Ethernet 2")
Then we add an static DNS server to this interface
interface ip show config
interface ipv4 set dns name="Ehternet 2" static 8.8.8.8
exit
nslookup aka.ms
S C:\> nslookup aka.ms
Server: dns.google
Address: 8.8.8.8
Non-authoritative answer:
Name: aka.ms
Address: 23.38.17.26