Replace ship lab by kustomize lab

2026-07-18 04:19:43 +00:00 · 2023-05-23 15:44:40 +02:00
parent 74add4d435
commit e66b90eb4e
1 changed files with 90 additions and 138 deletions
--- a/slides/k8s/kustomize.md
+++ b/slides/k8s/kustomize.md
@@ -208,49 +208,47 @@ class: extra-details

 - There are many ways to manage `kustomization.yaml` files, including:

-  - web wizards like [Replicated Ship](https://www.replicated.com/ship/)
-
  - the `kustomize` CLI

  - opening the file with our favorite text editor

+  - ~~web wizards like [Replicated Ship](https://www.replicated.com/ship/)~~ (deprecated)
+
 - Let's see these in action!

 ---

-## An easy way to get started with Kustomize
+## Working with the `kustomize` CLI

- We are going to use [Replicated Ship](https://www.replicated.com/ship/) to experiment with Kustomize
+General workflow:

- The [Replicated Ship CLI](https://github.com/replicatedhq/ship/releases) has been installed on our clusters
+1. `kustomize create` to generate an empty `kustomization.yaml` file

- Replicated Ship has multiple workflows; here is what we will do:
+2. `kustomize edit add resource` to add Kubernetes YAML files to it

-  - initialize a Kustomize overlay from a remote GitHub repository
+3. `kustomize edit add patch` to add patches to said resources

-  - customize some values using the web UI provided by Ship
+4. `kustomized edit add ...` or `kustomize edit set ...` (many options!)

-  - look at the resulting files and apply them to the cluster
+5. `kustomize build | kubectl apply -f-` or `kubectl apply -k .`
+
+6. Repeat steps 4-5 as many times as necessary!

 ---

-## Getting started with Ship
+## Why work with the CLI?

- We need to run `ship init` in a new directory
+- Editing manually can introduce errors and typos

- `ship init` requires a URL to a remote repository containing Kubernetes YAML
+- With the CLI, we don't need to remember the name of all the options and parameters

- It will clone that repository and start a web UI
+  (just add `--help` after any command to see possible options!)

- Later, it can watch that repository and/or update from it
-
- We will use the [jpetazzo/kubercoins](https://github.com/jpetazzo/kubercoins) repository
-
-  (it contains all the DockerCoins resources as YAML files)
+- Make sure to install the completion and try e.g. `kustomize eidt add [TAB][TAB]`

 ---

-## `ship init`
+## `kustomize create`

 .lab[

@@ -260,137 +258,24 @@ class: extra-details
  cd ~/kustomcoins
  ```

- Run `ship init` with the kustomcoins repository:
+- Run `kustomize create` with the kustomcoins repository:
  ```bash
-  ship init https://github.com/jpetazzo/kubercoins
+  kustomize create --resources https://github.com/jpetazzo/kubercoins
  ```

-<!-- ```wait Open browser``` -->
+<!-- ```look at the files``` -->
+
+- Run `kustomize build | kubectl apply -f-`

 ]

 ---

-## Access the web UI
-
- `ship init` tells us to connect on `localhost:8800`
-
- We need to replace `localhost` with the address of our node
-
-  (since we run on a remote machine)
-
- Follow the steps in the web UI, and change one parameter
-
-  (e.g. set the number of replicas in the worker Deployment)
-
- Complete the web workflow, and go back to the CLI
-
---
-
-## Inspect the results
-
- Look at the content of our directory
-
- `base` contains the kubercoins repository + a `kustomization.yaml` file
-
- `overlays/ship` contains the Kustomize overlay referencing the base + our patch(es)
-
- `rendered.yaml` is a YAML bundle containing the patched application
-
- `.ship` contains a state file used by Ship
-
---
-
-## Using the results
-
- We can `kubectl apply -f rendered.yaml`
-
-  (on any version of Kubernetes)
-
- Starting with Kubernetes 1.14, we can apply the overlay directly with:
-  ```bash
-  kubectl apply -k overlays/ship
-  ```
-
- But let's not do that for now!
-
- We will create a new copy of DockerCoins in another namespace
-
---
-
-## Deploy DockerCoins with Kustomize
-
-.lab[
-
- Create a new namespace:
-  ```bash
-  kubectl create namespace kustomcoins
-  ```
-
- Deploy DockerCoins:
-  ```bash
-  kubectl apply -f rendered.yaml --namespace=kustomcoins
-  ```
-
- Or, with Kubernetes 1.14, we can also do this:
-  ```bash
-  kubectl apply -k overlays/ship --namespace=kustomcoins
-  ```
-
-]
-
---
-
-## Checking our new copy of DockerCoins
-
- We can check the worker logs, or the web UI
-
-.lab[
-
- Retrieve the NodePort number of the web UI:
-  ```bash
-  kubectl get service webui --namespace=kustomcoins
-  ```
-
- Open it in a web browser
-
- Look at the worker logs:
-  ```bash
-  kubectl logs deploy/worker --tail=10 --follow --namespace=kustomcoins
-  ```
-
-<!--
-```wait units of work done``` 
-```key ^C```
-->
-
-]
-
-Note: it might take a minute or two for the worker to start.
-
---
-
-## Working with the `kustomize` CLI
-
- This is another way to get started
-
- General workflow:
-
-  `kustomize create` to generate an empty `kustomization.yaml` file
-
-  `kustomize edit add resource` to add Kubernetes YAML files to it
-
-  `kustomize edit add patch` to add patches to said resources
-
-  `kustomize build | kubectl apply -f-` or `kubectl apply -k .`
-
---
-
 ## `kubectl` integration

 - Kustomize has been integrated in `kubectl` (since Kubernetes 1.14)

-  - `kubectl kustomize` can apply a kustomization
+  - `kubectl kustomize` is an equivalent to `kustomize build`

  - commands that use `-f` can also use `-k` (`kubectl apply`/`delete`/...)

@@ -426,6 +311,45 @@ class: extra-details

 ---

+## Adding labels
+
+Labels can be added to all resources liks this:
+
+```yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+...
+commonLabels:
+  app.kubernetes.io/name: dockercoins
+```
+
+Or with the equivalent CLI command:
+
+```bash
+kustomize edit add label app.kubernetes.io/name:dockercoins
+```
+
+---
+
+## Use cases for labels
+
+- Example: clean up components that have been removed from the kustomization
+
+- Assuming that `commonLabels` have been set as shown on the previous slide:
+  ```bash
+    kubectl apply -k . --prune --selector app.kubernetes.io.name=dockercoins
+  ```
+
+- ... This command removes resources that have been removed from the kustomization
+
+- Technically, resources with:
+
+  - a `kubectl.kubernetes.io/last-applied-configuration` annotation
+
+  - labels matching the given selector
+
+---
+
 ## Scaling

 Instead of using a patch, scaling can be done like this:
@@ -439,6 +363,12 @@ replicas:
  count: 5
 ```

+or the CLI equivalent:
+
+```bash
+kustomize edit set replicas worker=5
+```
+
 It will automatically work with Deployments, ReplicaSets, StatefulSets.

 (For other resource types, fall back to a patch.)
@@ -465,6 +395,28 @@ images:
  digest: sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3
 ```

+
+---
+
+## Updating images with the CLI
+
+To add an entry in the `images:` section of the kustomization:
+
+```bash
+kustomize edit set image name=[newName][:newTag][@digest]
+```
+
+- `[]` denote optional parameters
+
+- `:` and `@` are the delimiters used to indicate a field
+
+Examples:
+```bash
+kustomize edit set image dockercoins/worker=ghcr.io/dockercoins/worker
+kustomize edit set image dockercoins/worker=ghcr.io/dockercoins/worker:v0.2
+kustomize edit set image dockercoins/worker=:v0.2
+```
+
 ---

 ## Updating images, pros and cons