Three control planes, one comparison, written from your own notes¶
Artifact — objective 8's deliverable: a written comparison of the three control planes this phase put in front of you, each row answerable only from something you did rather than something you read.
Rests on — everything. The hand-wired cluster from module 3.0, the kubeadm cluster you ran modules 3.3 to 3.5 on, and k0s. Two of the three no longer exist, which is why this exercise is a write-up and why the write-downs were mandatory.
Topology — k0s-light, for the last time — you need it running to check the k0s column rather than recall it.
Do
- Fill this in. Every cell must be traceable to a note you took or a command you can still run:
| Very Hard Way | kubeadm | k0s | |
|---|---|---|---|
| Processes in the control plane | |||
| What supervises them | |||
| Where etcd runs | |||
| Who signed the certificates | |||
| Number of flags you chose yourself | |||
| How a component is restarted | |||
| Smallest failure that takes it all down | |||
| Where the configuration lives on disk | |||
| Time from nothing to serving | |||
| What you would have to change to add a second control-plane node |
-
The last row is the one you have not done. Answer it by reading, not by building —
hais P11's topology and this phase does not have room for it. For each of the three, name the specific thing: the flag, the command, or the config stanza. -
Then answer the question the table is for, in a paragraph rather than a cell: what does each of the three make easy, and what does each make invisible? Every one of them hides something the next one down does not, and the ordering is not a straight line — k0s hides more than kubeadm in one respect and less in another. Find that respect.
-
Check one claim you are least sure of, live, on the cluster still running.
Expect — the flag-count row is the one that produces the argument. It is not a proxy for control; it is a proxy for how many decisions you were required to have an opinion about, and the Very Hard Way's number is high because you were made to have opinions about things that have one correct answer. That distinction — a decision worth making versus a decision worth defaulting — is the whole case for a distribution, and it is the case you are now in a position to argue on evidence.
The "makes invisible" answers are the ones that will matter in six months: what you cannot debug on each, because you were never shown the seam.
Write down — the table and the paragraph. This is the artifact; there is no separate write-down.
Teardown — nothing was created. The topology goes:
The capstone is next and re-provisions its own cluster; see its footprint note for why that re-provision is the phase's one deliberate repeat.