Use the kubeadmin for minikube

[hwchiu]

• Since the kubeadm is relay on systemd, we should use the ubuntu 16.04 as the OS.
• Fix the version of the minikube to 0.28.1
• Change the bootstrapper from localkube to kubeadm

[xmudrii]

Thank you so much for the contribution!! 👍 This looks and seems to work great!

I have researched about this earlier and I left a comment with some details about what I found out so far.

As mentioned, I don't have strong opinions on this problem. I would love to see this merged, as with kubeadm bootstrapper we could use the latest Kubernetes version.

Maybe I would just add a note that xenial is beta, so users know if some problems appear.

Of course, I will leave it on @lilic to decide is it okay to merge this. :)

Thank you so much!

[xmudrii]

Is it safe to use dist: xenial?

I was researching about it, however, I was not able to find any fresh information about that. The newest information I found is about 3 months old.

16.04 (Xenial) is still not officially supported by Travis-CI. The image is available, but it can disappear at any time and it is not guaranteed that builds will work.

Some references:

• The Travis-CI documentation states only that Trusty, Precise (note that 12.04 has reached EOL) and macOS. However, it doesn't state when the document has been updated last time.
• travis-ci/travis-ci#5821, the old one, but has some context about the issues. At that time (2016 and 2017), it was not know when is Xenial going to get published.
• travis-ci/travis-ci#7260. The last comment is from 3-4 months ago, but no update from Travis team, and the issue got locked after that. Also, there's a comment stating that it may or may not work, and that it's not supported.
• This PR (travis-ci/travis-yml#16) added Xenial support to Travis-CI, but marked as Edge feature (it is still marked as an edge feature). Following the mentioned issues from that one, there are reported problems from April that builds were randomly failing.

However, some of the problems seems solved. The build details are now correct, and reports Xenial instead of Trusty:

Operating System Details
Distributor ID:	Ubuntu
Description:	Ubuntu 16.04.5 LTS
Release:	16.04
Codename:	xenial

I don't have strong opinions on this one. Moreover, I would really love this to get merged! The localkube bootstrap is deprecated by the Minikube team, and switching to kubeadm would help a lot.

[hwchiu]

@xmudrii Thanks your rapid reply.
As I know, it's absolute not safe to use xenial here (It's beta feature and you already know).

In my opinion, that's a trade off and I agree with you that we should use some documents to tell the developers xenial is a beta feature and let them choose what kind of the combination they want to use.

1. kubeadm + beta:xenial
2. localkube + stable ubuntu.

[xmudrii]

@hwchiu I agree with you.

What we can do is to create a new branch, and then merge the PR against that branch. Then update the README files in all three branches to include a short comparison between each other and note what's the recommended solution.

In that case, we would have examples for all three cases.

I think you can't create a new branch, but if that makes sense and Lili agrees, Lili or I can do it for you. Then, you will be able to update the PR to use the new branch.

[lilic]

@hwchiu I created a new branch https://github.com/LiliC/travis-minikube/tree/kubeadm/xenial feel free to change the PR to be merged to that. And we can after that do a followup with the README updated. Thanks! Sorry for not getting back to your earlier!

[hwchiu]

@lilic
Thanks your help 👍
Since the base branch of this PR is different of kubeadm/xenial branch, there're some conflicts and should I open another PR to handle the kubeadm for kubeadm/xenial branch?

[xmudrii]

@hwchiu Looks like you're based on the 1.10 branch. I will recreate the kubeadm/xenial, so you can merge without creating a new PR.

[xmudrii]

@hwchiu I've created a new kubeadm/xenial branch based of 1.10 branch. Try again now and let me know does it work for you.

[hwchiu]

Thanks your help and I have change the target branch to kubeadm/xenial

[fabiand]

@hwchiu could you please re-trigger the travis build to see if it still works today?

[xmudrii]

@fabiand Done. The build is passing as intended.

If you have .travis.yml to share, I can take a look to see what could be a problem when I have some time. :)

[fabiand]

The language made the difference!
generic: Fails to come up https://travis-ci.com/fabiand/common-templates/jobs/143413716
unset (ruby): Cluster comes up https://travis-ci.com/fabiand/common-templates/builds/83612971

[fabiand]

Thanks. It was really the language, my RP is here: https://github.com/fabiand/common-templates/pull/1 (not as embarassing hacky as before ;) )

[lilic]

Of course, I will leave it on @lilic to decide is it okay to merge this. :)

lgtm and I agree with creating the branches! Thank you for this, both of you!

[lilic]

@hwchiu Thanks again! Would you like to open a PR to point to this branch in the master README file?

[hwchiu]

Yes, I can do that.

[fabiand]

FYI I have a similar repo now: https://github.com/fabiand/traviskube/

It tests with minikube, oc cluster, and I'm also working on minishift (which internally is also using oc cluster, but is still doing it's distinct setup).