merge

k8s/efk.yaml

@@ -32,13 +32,16 @@ subjects:
   name: fluentd
   namespace: default
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: DaemonSet
 metadata:
   name: fluentd
   labels:
     app: fluentd
 spec:
+  selector:
+    matchLabels:
+      app: fluentd
   template:
     metadata:
       labels:
@@ -86,7 +89,7 @@ spec:
         hostPath:
           path: /var/lib/docker/containers
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   labels:
@@ -128,7 +131,7 @@ spec:
     app: elasticsearch
   type: ClusterIP
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   labels:

k8s/ingress.yaml

@@ -1,13 +1,13 @@
 apiVersion: networking.k8s.io/v1beta1
 kind: Ingress
 metadata:
-  name: cheddar
+  name: kibana
 spec:
   rules:
-  - host: cheddar.A.B.C.D.nip.io
+  - host: kibana.185.145.251.54.nip.io
     http:
       paths:
       - path: /
         backend:
-          serviceName: cheddar
-          servicePort: 80
+          serviceName: kibana
+          servicePort: 5601

k8s/insecure-dashboard.yaml

@@ -162,7 +162,7 @@ spec:
   selector:
     k8s-app: kubernetes-dashboard
 ---
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   labels:

k8s/local-path-storage.yaml

@@ -45,7 +45,7 @@ subjects:
   name: local-path-provisioner-service-account
   namespace: local-path-storage
 ---
-apiVersion: apps/v1beta2
+apiVersion: apps/v1
 kind: Deployment
 metadata:
   name: local-path-provisioner

k8s/traefik.yaml

@@ -6,13 +6,16 @@ metadata:
   namespace: kube-system
 ---
 kind: DaemonSet
-apiVersion: extensions/v1beta1
+apiVersion: apps/v1
 metadata:
   name: traefik-ingress-controller
   namespace: kube-system
   labels:
     k8s-app: traefik-ingress-lb
 spec:
+  selector:
+    matchLabels:
+      k8s-app: traefik-ingress-lb
   template:
     metadata:
       labels:
@@ -26,7 +29,7 @@ spec:
       serviceAccountName: traefik-ingress-controller
       terminationGracePeriodSeconds: 60
       containers:
-      - image: traefik
+      - image: traefik:1.7
         name: traefik-ingress-lb
         ports:
         - name: http

slides/k8s/buildshiprun-dockerhub.md

@@ -33,7 +33,7 @@
   **make sure that you set `$REGISTRY` and `$TAG` first!**
 
 - For example:
-  ```
+  ```bash
   export REGISTRY=dockercoins TAG=v0.1
   ```
 

slides/k8s/dashboard.md

@@ -105,6 +105,22 @@ The dashboard will then ask you which authentication you want to use.
 
 ---
 
+## Other dashboards
+
+- [Kube Web View](https://codeberg.org/hjacobs/kube-web-view)
+
+  - read-only dashboard
+
+  - optimized for "troubleshooting and incident response"
+
+  - see [vision and goals](https://kube-web-view.readthedocs.io/en/latest/vision.html#vision) for details
+
+- [Kube Ops View](https://github.com/hjacobs/kube-ops-view)
+
+  - "provides a common operational picture for multiple Kubernetes clusters"
+
+---
+
 # Security implications of `kubectl apply`
 
 - When we do `kubectl apply -f <URL>`, we create arbitrary resources
@@ -156,4 +172,3 @@ The dashboard will then ask you which authentication you want to use.
 - It introduces new failure modes
 
   (for instance, if you try to apply YAML from a link that's no longer valid)
-

slides/k8s/dryrun.md

@@ -0,0 +1,209 @@
+# Authoring YAML
+
+- There are various ways to generate YAML with Kubernetes, e.g.:
+
+  - `kubectl run`
+
+  - `kubectl create deployment` (and a few other `kubectl create` variants)
+
+  - `kubectl expose`
+
+- When and why do we need to write our own YAML?
+
+- How do we write YAML from scratch?
+
+---
+
+## The limits of generated YAML
+
+- Many advanced (and even not-so-advanced) features require to write YAML:
+
+  - pods with multiple containers
+
+  - resource limits
+
+  - healthchecks
+
+  - DaemonSets, StatefulSets
+
+  - and more!
+
+- How do we access these features?
+
+---
+
+## We don't have to start from scratch
+
+- Create a resource (e.g. Deployment)
+
+- Dump its YAML with `kubectl get -o yaml ...`
+
+- Edit the YAML
+
+- Use `kubectl apply -f ...` with the YAML file to:
+
+  - update the resource (if it's the same kind)
+
+  - create a new resource (if it's a different kind)
+
+- Or: Use The Docs, Luke
+
+  (the documentation almost always has YAML examples)
+
+---
+
+## Generating YAML without creating resources
+
+- We can use the `--dry-run` option
+
+.exercise[
+
+- Generate the YAML for a Deployment without creating it:
+  ```bash
+  kubectl create deployment web --image nginx --dry-run
+  ```
+
+]
+
+- We can clean up that YAML even more if we want
+
+  (for instance, we can remove the `creationTimestamp` and empty dicts)
+
+---
+
+## Using `--dry-run` with `kubectl apply`
+
+- The `--dry-run` option can also be used with `kubectl apply`
+
+- However, it can be misleading (it doesn't do a "real" dry run)
+
+- Let's see what happens in the following scenario:
+
+  - generate the YAML for a Deployment
+
+  - tweak the YAML to transform it into a DaemonSet
+
+  - apply that YAML to see what would actually be created
+
+---
+
+## The limits of `kubectl apply --dry-run`
+
+.exercise[
+
+- Generate the YAML for a deployment:
+  ```bash
+  kubectl create deployment web --image=nginx -o yaml > web.yaml
+  ```
+
+- Change the `kind` in the YAML to make it a `DaemonSet`:
+  ```bash
+  sed -i s/Deployment/DaemonSet/ web.yaml
+  ```
+
+- Ask `kubectl` what would be applied:
+  ```bash
+  kubectl apply -f web.yaml --dry-run --validate=false -o yaml
+  ```
+
+]
+
+The resulting YAML doesn't represent a valid DaemonSet.
+
+---
+
+## Server-side dry run
+
+- Since Kubernetes 1.13, we can use [server-side dry run and diffs](https://kubernetes.io/blog/2019/01/14/apiserver-dry-run-and-kubectl-diff/)
+
+- Server-side dry run will do all the work, but *not* persist to etcd
+
+  (all validation and mutation hooks will be executed)
+
+.exercise[
+
+- Try the same YAML file as earlier, with server-side dry run:
+  ```bash
+  kubectl apply -f web.yaml --server-dry-run --validate=false -o yaml
+  ```
+
+]
+
+The resulting YAML doesn't have the `replicas` field anymore.
+
+Instead, it has the fields expected in a DaemonSet.
+
+---
+
+## Advantages of server-side dry run
+
+- The YAML is verified much more extensively
+
+- The only step that is skipped is "write to etcd"
+
+- YAML that passes server-side dry run *should* apply successfully
+
+  (unless the cluster state changes by the time the YAML is actually applied)
+
+- Validating or mutating hooks that have side effects can also be an issue
+
+---
+
+## `kubectl diff`
+
+- Kubernetes 1.13 also introduced `kubectl diff`
+
+- `kubectl diff` does a server-side dry run, *and* shows differences
+
+.exercise[
+
+- Try `kubectl diff` on the YAML that we tweaked earlier:
+  ```bash
+  kubectl diff -f web.yaml
+  ```
+
+]
+
+Note: we don't need to specify `--validate=false` here.
+
+---
+
+## Advantage of YAML
+
+- Using YAML (instead of `kubectl run`/`create`/etc.) allows to be *declarative*
+
+- The YAML describes the desired state of our cluster and applications
+
+- YAML can be stored, versioned, archived (e.g. in git repositories)
+
+- To change resources, change the YAML files
+
+  (instead of using `kubectl edit`/`scale`/`label`/etc.)
+
+- Changes can be reviewed before being applied
+
+  (with code reviews, pull requests ...)
+
+- This workflow is sometimes called "GitOps"
+
+  (there are tools like Weave Flux or GitKube to facilitate it)
+
+---
+
+## YAML in practice
+
+- Get started with `kubectl run`/`create`/`expose`/etc.
+
+- Dump the YAML with `kubectl get -o yaml`
+
+- Tweak that YAML and `kubectl apply` it back
+
+- Store that YAML for reference (for further deployments)
+
+- Feel free to clean up the YAML:
+
+  - remove fields you don't know
+
+  - check that it still works!
+
+- That YAML will be useful later when using e.g. Kustomize or Helm

slides/k8s/healthchecks-more.md

@@ -370,6 +370,8 @@ class: extra-details
 
   (and have gcr.io/pause take care of the reaping)
 
+- Discussion of this in [Video - 10 Ways to Shoot Yourself in the Foot with Kubernetes, #9 Will Surprise You](https://www.youtube.com/watch?v=QKI-JRs2RIE)
+
 ---
 
 ## Healthchecks for worker

slides/k8s/resource-limits.md

@@ -515,3 +515,24 @@ services.nodeports               0     0
   (with `kubectl describe resourcequota ...`)
 
 - Rinse and repeat regularly
+
+---
+
+## Additional resources
+
+- [A Practical Guide to Setting Kubernetes Requests and Limits](http://blog.kubecost.com/blog/requests-and-limits/)
+
+  - explains what requests and limits are
+
+  - provides guidelines to set requests and limits
+
+  - gives PromQL expressions to compute good values
+    <br/>(our app needs to be running for a while)
+
+- [Kube Resource Report](https://github.com/hjacobs/kube-resource-report/)
+
+  - generates web reports on resource usage
+
+  - [static demo](https://hjacobs.github.io/kube-resource-report/sample-report/output/index.html)
+    |
+    [live demo](https://kube-resource-report.demo.j-serv.de/applications.html)

slides/kube-fullday.yml

@@ -51,6 +51,7 @@ chapters:
   - k8s/scalingdockercoins.md
   - shared/hastyconclusions.md
   - k8s/daemonset.md
+  #- k8s/dryrun.md
   - k8s/rollout.md
   #- k8s/healthchecks.md
   #- k8s/healthchecks-more.md