travis-ci seems to always rebuild images without skipping

[clkao]

(from jupyterhub/zero-to-jupyterhub-k8s#1260 (comment))

in a local dev env, i see Skipping build for jupyterhub/k8s-hub:0.9-c9f80ce, it already exists when running chartpress. but this is somehow not the case on travis, for example: https://travis-ci.org/jupyterhub/zero-to-jupyterhub-k8s/jobs/526434320#L536

[clkao]

it appears docker on travis has registry mirror configured. this made the image check failed, so chartpress would not skip build: https://travis-ci.org/jupyterhub/zero-to-jupyterhub-k8s/jobs/577422531#L561

[clkao]

This appears to be caused by moby/moby#39120

[consideRatio]

@clkao, do you have a suggestion on a way forward here? I've tried to grasp the situation but I struggle to both grasp the problem fully and how to proceed to resolve it in a good way.

[consideRatio]

@clkao figured out a workaround for moby/moby#39120, to reset /etc/docker/daemon.json to not include the registry mirror and restart the docker daemon.

sudo cat /etc/docker/daemon.json
echo '{"mtu": 1460}' | sudo dd of=/etc/docker/daemon.json
sudo systemctl restart docker
docker ps -a

With this knowledge, I think it is out of scope for chartpress to make a change. Should we close this issue?

[minrk]

@consideRatio yeah, maybe. if there's another easy way to check if docker pull would work (I'm assuming it would in this case), that would be awesome, but this is a sensible "not our fault" kind of thing.

[consideRatio]

Closing this issue as it is resolved with @clkao's docker-fix script that modifies /etc/docker/daemon.json to not include the registry mirror. This is also implemented within z2jh now.

chartpress/.travis.yml

Lines 20 to 21 in 1e07bd0

	echo '{"mtu": 1460}' | sudo dd of=/etc/docker/daemon.json &&
	sudo systemctl restart docker