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From: Ludovic Piot <ludovic.piot@thegaragebandofit.com>
Date: Wed, 4 Jun 2025 23:55:33 +0200
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+# Multi-tenants management with Flux
+
+💡 Thanks to `Flux`, we can manage Kubernetes resources from inside the clusters.
+
+The **_⚙️OPS_** team uses `Flux` with a _GitOps_ code base to:
+- configure the clusters
+- deploy tools and components to extend the clusters capabilites
+- configure _GitOps_ workflow for dev teams in **dedicated and isolated tenants**
+
+The **_🎸ROCKY_** team uses `Flux` to deploy every new release of its app, by detecting every new `git push` events happening in its app `Github` repository
+
+
+The **_🎬MOVY_** team uses `Flux` to deploy every new release of its app, packaged and published in a new `Helm` chart release
+
+---
+
+## Creating tenants with Flux
+
+While basic `Flux` behavior is to use a single configuration directory applied by a cluster-wide role…
+
+… it can also enable _multi-tenant_ configuration by:
+- creating dedicated directories for each tenant in its configuration code base
+- and using a dedicated `ServiceAccount` with limited permissions to operate in each tenant
+
+Several tenants are created
+- per env
+  - for **_⚗️TEST_**
+  - and **_🏭PROD_**
+- per team
+  - for **_🎸ROCKY_**
+  - and **_🎬MOVY_**
+
+---
+
+class: pic
+
+![Multi-tenants clusters](images/M6-cluster-multi-tenants.png )
+
+---
+
+### The command line 1/2
+
+Creating the **_⚗️TEST_** tenant
+
+.lab[
+
+```bash
+shpod:~# cd fleet-config-using-flux-XXXXX/
+shpod:~/fleet-config-using-flux-lpiot# flux create kustomization tenants \
+    --namespace=flux-system            \
+    --source=GitRepository/flux-system \
+    --path ./tenants/test              \
+    --prune                            \
+    --interval=1m                      \
+    --export >> clusters/CLOUDY/tenants.yaml
+```
+
+]
+
+---
+
+### The command line 2/2
+
+Then we create the **_🏭PROD_** tenant
+
+.lab[
+
+```bash
+shpod:~/fleet-config-using-flux-lpiot# flux create kustomization tenants \
+    --namespace=flux-system            \
+    --source=GitRepository/flux-system \
+    --path ./tenants/prod              \
+    --prune                            \
+    --interval=3m                      \
+    --export >> clusters/CLOUDY/tenants.yaml
+```
+
+]
+
+---
+
+### 📂 Flux tenants.yaml files
+
+Let's review the `fleet-config-using-flux-XXXXX/clusters/CLOUDY/tenants.yaml` file
+
+
+
+
+⚠️ The last command we type in `Flux` _CLI_ creates the `YAML` manifest **locally**
+
+> ☝🏻 Don't forget to `git commit` and `git push` to `Github`!
+
+---
+
+### Our 1st Flux error
+
+.lab[
+
+```bash
+shpod:~/fleet-config-using-flux-lpiot# flux get all
+NAMESPACE       NAME                            REVISION                SUSPENDED
+      READY   MESSAGE
+flux-system     gitrepository/flux-system       main@sha1:4db19114      False
+      True    stored artifact for revision 'main@sha1:4db19114'
+
+NAMESPACE       NAME                            REVISION                SUSPENDED
+      READY   MESSAGE                                 
+flux-system     kustomization/flux-system       main@sha1:d48291a8      False
+      False   kustomize build failed: accumulating resources: accumulation err='accumulating resources from './tenants.yaml': may not add resource with an already registered id: Kustomization.v1.kustomize.toolkit.fluxcd.io/tenants.flux-system': must build at directory: '/tmp/kustomization-689086759/clusters/CLOUDY/tenants.yaml': file is not directory
+```
+
+]
+
+> Our configuration may be incomplete 😅
+
+---
+
+## Configuring Flux for the **_🎸ROCKY_** team
+
+What the **_⚙️OPS_** team has to do:
+
+- 🔧 Create a dedicated `rocky` _tenant_ for _**⚗️TEST**_ and **_🏭PROD_** envs on the cluster
+
+- 🔧 Create the `Flux` source pointing to the `Github` repository embedding the **_🎸ROCKY_** app source code
+
+- 🔧 Add a `kustomize` _patch_ into the global `Flux` config to include this specific `Flux` config. dedicated to the deployment of the **_🎸ROCKY_** app
+
+What the **_🎸ROCKY_** team has to do:
+
+- 👨‍💻 Create the `kustomization.yaml` file in the **_🎸ROCKY_** app source code repository on `Github`