The Divio app shows an error when setting up the local Docker container because (according to 'divio doctor') DNS resolution inside Docker doesn't work.
I've setup an Ubuntu 18.1 VBox VM on a W10 host to serve as a Divio local development box. DNS resolution was never a problem when running Docker on the host though.
I added "dns": [8.8.8.8] to /etc/docker/daemon.json to get DNS to work from the terminal.
The following command returns the correct answer:
docker run busybox nslookup control.divio.com
Server: 8.8.8.8
Address: 8.8.8.8:53
Non-authoritative answer:
Name: control.divio.com
Address: 217.150.252.173
Anyone has an idea how to fix this?
What's happening is this: the command executed inside the container to test for DNS resolution (nslookup control.divio.com) has a 5 second timeout.
Your command (docker run busybox nslookup control.divio.com does just the same thing - but without the timeout.
For whatever reason, it's taking longer than 5 seconds to get a response, hence the failure in the first case.
It's not entirely clear why this sometimes happens, with no obvious reason - DNS resolution should not take so long.
You can disable this test though, by adding docker-server-dns to skip_doctor_checks in the ~/.aldryn file. See the Divio Cloud documentation for details.
The Divio App has been updated (to version 0.13.1) that you will be offered when you next launch it, along with the Divio CLI (to version 3.3.10) which if you use outside the Divio Shell can be installed with pip install --upgrade divio-cli.
In this update the way the lookup works has been changed to mitigate the effects of network problems when it does the DNS check (it now does a more restricted check).
You should now be able to re-enable the disabled docker-server-dns test in the ~/.aldryn file.
To complicate matters, it turns out that the Busybox image used to run these tests has changed in recent versions and it's quite difficult to ensure that the commands used in the test will work with whatever version of Busybox the user happens to have.
Running docker pull busybox will update the image, and for many users this has solved the issues. Some users will be able to reinstate the tests described above that would fail.