When following all the instructions, the Helm Chart that
we create is buggy, and the app shows up but with a zero
hash rate. This explains why, and how to fix it.
Fixes#432
Consul 1.4 introduces Cloud auto-join, which finds the
IP addresses of the other nodes by querying an API (in
that case, the Kubernetes API).
This involves creating a service account and granting
permissions to list and get pods. It is a little bit
more complex, but it reuses previous notions (like RBAC)
so I like it better.
This reformulates the section where we run DockerCoins
to better explain why we use images (and how they are
essential to the "ship" part of the action), and it
tells upfront that it will be possible to use images
from the Docker Hub (and skip altogether the part where
we run our own registry and build and push images).
It also reshuffles section headers a bit, because that
part had a handful of really small sections. Now we
have:
- Shipping images with a registry
- Running our application on Kubernetes
I think that's better.
It also paves the way to make the entire self-hosted
registry part optional.
We show how to change namespace by creating a new context, then
switching to the new context. It works, but it is very cumbersome.
Instead, let's just update the current context, and give some
details about when it's better to update the current context, and
when it is better to use different contexts and hop between them.
This supersedes #399.
There was a bug in Kubernetes 1.12. It was fixed in 1.13.
Let's just mention the issue in one brief slide but not add
too much extra fluff about it.
This was a request by @abuisine, so I'm flagging him for review :-)
This section explains the challenges associated with self-hosting
the control plane; and segues into static pods. It also mentions
bootkube and the Pod Checkpointer. There is an exercise showing
how to run a static pod.
The old version was using a slightly confusing way to
show which pods were receiving traffic:
kubectl logs --tail 1 --selector app=rng
(And then we look at the timestamp of the last request.)
In this new version, concepts are introduced progressively;
the YAML parser magic is isolated from the other concerns;
we show the impact of removing a pod from load balancing
in a way that is (IMHO) more straightforward:
- follow logs of specific pod
- remove pod from load balancer
- logs instantly stop flowing
These slides also explain why the DaemonSet and the
ReplicaSet for the rng service don't step on each other's
toes.
We have images on the Docker Hub for the various components
of dockercoins. Let's add one slide explaining how to use that,
for people who would be lost or would have issues with their
registry, so that they can catch up.
kubectl run is being deprecated as a multi-purpose tool.
This PR replaces 'kubectl run' with 'kubectl create deployment'
in most places (except in the very first example, to reduce the
cognitive load; and when we really want a single-shot container).
It also updates the places where we use a 'run' label, since
'kubectl create deployment' uses the 'app' label instead.
NOTE: this hasn't gone through end-to-end testing yet.
For each concept that is present in the full-length tutorial,
I added a link to the corresponding chapter in the final section,
so that people who liked the short version can get similarly
presented info from the longer version.
