📝 Add OpenEBS install chapter

2026-07-28 01:01:12 +00:00 · 2025-06-11 19:24:13 +02:00
parent a165e60407
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--- a/slides/k8s/M6-K03-openebs-install.md
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+# K03- Installing OpenEBS as our CSI
+
+`OpenEBS` is a _CSI_ solution capable of hyperconvergence, synchronous replication and other extra features.  
+It installs with `Helm` charts.
+
+- `Flux` is able to watch `Helm` repositories and install `HelmReleases`
+- To inject its configuration into the `Helm chart` , `Flux` relies on a `ConfigMap` including the `values.yaml` file
+
+.lab[
+
+```bash
+k8s@shpod ~$  mkdir -p ./clusters/METAL/openebs/ &&                  \
+              cp -pr ~/container.training/k8s/M6-openebs-*.yaml      \
+                    ./clusters/METAL/openebs/ &&                     \
+              cd ./clusters/METAL/openebs/ &&                        \
+              mv M6-openebs-kustomization.yaml kustomization.yaml && \
+              cd - 
+```
+
+]
+
+---
+
+## Creating an `Helm` source in Flux for OpenEBS Helm chart
+
+.lab[
+
+```bash
+k8s@shpod ~$ flux create source helm openebs \
+    --url=https://openebs.github.io/openebs  \
+    --interval=3m                            \
+    --export > ./clusters/METAL/openebs/sync.yaml
+```
+
+]
+
+---
+
+## Creating the `HelmRelease` in Flux
+
+.lab[
+
+```bash
+k8s@shpod ~$ flux create helmrelease openebs    \
+    --namespace=openebs                         \
+    --source=HelmRepository/openebs.flux-system \
+    --chart=openebs                             \
+    --values-from=ConfigMap/openebs-values     \
+    --export >> ./clusters/METAL/openebs/sync.yaml
+```
+
+]
+
+---
+
+## 📂 Let's review the files
+
+- `M6-openebs-components.yaml`
+  </br>To include the `Flux` resources in the same _namespace_ where `Flux` installs the `OpenEBS` resources, we need to create the _namespace_ **before** the installation occurs
+
+- `sync.yaml`
+  </br>The resources `Flux` uses to watch and get the `Helm chart`
+  
+- `M6-openebs-values.yaml`
+  </br> the `values.yaml` file that will be injected into the `Helm chart`
+
+- `kustomization.yaml`
+  </br>This one is a bit special: it includes a [ConfigMap generator](https://kubectl.docs.kubernetes.io/references/kustomize/kustomization/configmapgenerator/)
+
+- `M6-openebs-kustomizeconfig.yaml`
+  </br></br>This one is tricky: in order for `Flux` to trigger an upgrade of the `Helm Release` when the `ConfigMap` is altered, you need to explain to the `Kustomize ConfigMap generator` how the resources are relating with each others. 🤯 
+ 
+And here we go!
+
+---
+
+class: pic
+
+![Running Mario](images/M6-running-Mario.gif)
+
+---
+
+## And the result
+
+Now, we have a _cluster_ featuring `openEBS`.  
+But still… The PersistentVolumeClaim remains in `Pending` state!😭
+
+```bash
+k8s@shpod ~$ kubectl get storageclass
+NAME               PROVISIONER        RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
+openebs-hostpath   openebs.io/local   Delete          WaitForFirstConsumer   false                  82m
+```
+We still don't have a default `StorageClass`!😤
+
+---
+
+### Manually enforcing the default `StorageClass`
+
+Even if Flux is constantly reconciling our resources, we still are able to test evolutions by hand.
+
+.lab[
+
+```bash
+k8s@shpod ~$ flux suspend helmrelease openebs -n openebs
+► suspending helmrelease openebs in openebs namespace
+✔ helmrelease suspended
+k8s@shpod ~$ kubectl patch storageclass openebs-hostpath \
+                -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
+
+k8s@shpod ~$ k get storageclass
+NAME                         PROVISIONER        RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
+openebs-hostpath (default)   openebs.io/local   Delete          WaitForFirstConsumer   false                  82m
+```
+
+]
+
+---
+
+### Now the database is OK
+
+```bash
+k8s@shpod ~$ get pvc,pods -n movy-test
+NAME                                         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS       VOLUMEATTRIBUTESCLASS   AGE
+persistentvolumeclaim/postgresql-data-db-0   Bound    pvc-ede1634f-2478-42cd-8ee3-7547cd7cdde2   1Gi        RWO            openebs-hostpath   <unset>                 20m
+
+NAME                       READY   STATUS    RESTARTS   AGE
+pod/db-0                   1/1     Running   0          5h43m
+(…)
+```