cloud-config: deprecate etcd2 and etcd and create new docs

[philips]

In a blog post a few weeks ago we announced deprecation of etcd2 and etcd in Container Linux. But, our docs haven't been updated. We need to do the following things:

• Deprecate etcd2 in the cloud-config docs
• Show people how to use etcd-member in the cloud-config docs

Issue filed based on feedback from Twitter: https://twitter.com/spidler/status/844350222524448773

[philips]

cc @coreos/team-docs we should do this ASAP.

[crawford]

Instead of coreos-cloudinit, we are going to show how this can be done via Container Linux Configs instead (coreos/container-linux-config-transpiler#37).

[radhikapc]

I do not have the permission to assign this defect to myself. @crawford please assign this defect to me. cc @philips

[radhikapc]

as discussed, will wait for the etcd team to complete the new version of docs that they are working on. Then we would be able to provide proper links to the docs, along with stating etcd2 is depreciated.

[crawford]

The etcd team has finished most of the documentation (if not all of it). We are really just waiting on the ct documentation @dgonyeo is working on. It should be ready by the end of the week.

[radhikapc]

@dgonyeo ping us once you merge the changes!

[philips]

@crawford We need both cloud-config and ignition, because:

1. Cloud-config is referenced everywhere in our docs and Google, the docs should be accurate
2. Some people already have cloud-config in their workflow
3. Some can't migrate to Ignition because of lack or platform support

[cgonyeo]

ping us once you merge the changes

@radhikapc the ct docs were merged: coreos/container-linux-config-transpiler#37

I'm now working on changing all the docs in coreos/docs to use container linux configs: coreos/docs#1024

This change results in the docs for all the platforms I can update (as in, have ignition support) being switched over to etcd v3. It's not in the cloud-config docs like this issue wanted, but mentioning it here because it's very related.

[radhikapc]

Thanx @dgonyeo. will look into this shortly.