Rework kube + conclusion
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@ -9,7 +9,7 @@ date=2022-04-04
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---
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Two months ago, we were impressed by the success of our open beta launch at FOSDEM and on Hacker News: [our intial post](https://garagehq.deuxfleurs.fr/blog/2022-introducing-garage/) lead to more than 40k views in 10 days, going up to 100 views/minute.
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Two months ago, we were impressed by the success of our open beta launch at FOSDEM and on Hacker News: [our initial post](https://garagehq.deuxfleurs.fr/blog/2022-introducing-garage/) lead to more than 40k views in 10 days, going up to 100 views/minute, and all requests were served by Garage without cache!
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Since this event, we continued to improve Garage, and - 2 months after the initial release - we are happy to announce version 0.7.0.
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But first, we would like to thank the contributors that made this new release possible: Alex, Jill, Max Audron, Maximilien, Quentin, Rune Henrisken, Steam, and trinity-1686a.
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@ -26,171 +26,40 @@ Besides bugfixes, there is two new features: a better Kubernetes integration and
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## Kubernetes integration
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Before Garage v0.7.0, you had to deploy a Consul cluster or spawn a "coordinating" pod to deploy Garage on Kubernetes.
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In this new version, Garage integrates a method to discover other peers by using Kubernetes [Custom Resources](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) to simplify cluster discovery.
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Garage can self-apply the [Custom Resource Definition](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/) (CRD) to your cluster, or you can manage it manually.
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Before Garage v0.7.0, you had to deploy a Consul cluster or spawn a "coordinating" pod to deploy Garage on [Kubernetes](https://kubernetes.io) (K8S).
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In this new version, Garage integrates a method to discover other peers by using Kubernetes [Custom Resources](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/) (CR) to simplify cluster discovery.
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Let's see practically how it works with a minimalistic example (not secured nor suitable for production).
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You can run it on [minikube](https://minikube.sigs.k8s.io) if you want a more interactive reading.
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CR discovery can be quickly enabled by configuring the name of the desired service (`kubernetes_namespace`) and which namespace to look for (`kubernetes_service_name`) in your Garage config:
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Start by creating a [ConfigMap](https://kubernetes.io/docs/concepts/configuration/configmap/) containing Garage's configuration (let's name it `config.yaml`):
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```yaml
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apiVersion: v1
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kind: ConfigMap
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metadata:
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name: garage-config
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namespace: default
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data:
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garage.toml: |-
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metadata_dir = "/mnt/fast"
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data_dir = "/mnt/slow"
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replication_mode = "3"
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rpc_bind_addr = "[::]:3901"
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rpc_secret = "<secret>"
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bootstrap_peers = []
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kubernetes_namespace = "default"
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kubernetes_service_name = "garage-daemon"
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kubernetes_skip_crd = false
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[s3_api]
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s3_region = "garage"
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api_bind_addr = "[::]:3900"
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root_domain = ".s3.garage.tld"
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[s3_web]
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bind_addr = "[::]:3902"
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root_domain = ".web.garage.tld"
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index = "index.html"
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```toml
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kubernetes_namespace = "default"
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kubernetes_service_name = "garage-daemon"
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```
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The 3 important parameters are `kubernetes_namespace`, `kubernetes_service_name`, and `kubernetes_skip_crd`.
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Configure them according to your planned deployment.
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The last one controls wether you want to create the CRD manually or allow Garage to create it automatically on startup.
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In this example, we keep it to `false`, which means we allow Garage to automatically create the CRD.
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Custom Resources must be defined *a priori* with [Custom Resource Definition](https://kubernetes.io/docs/tasks/extend-kubernetes/custom-resources/custom-resource-definitions/) (CRD).
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If the CRD does not exist, Garage can create it for you. It is enabled by default but it requires some additional permissions.
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If you prefer limiting accesses to your K8S cluster, you can create the resource manually and prevent Garage from automatically creating it:
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Apply this configuration on your cluster:
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```bash
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kubectl apply -f config.yaml
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```toml
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kubernetes_skip_crd = true
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```
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Allowing Garage to create the CRD is not enough, the process must have enough permissions.
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A quick unsecure way to add the permission is to create a [ClusterRoleBinding](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#rolebinding-and-clusterrolebinding) to give admin rights to our local user, effectively breaking Kubernetes' security model (we name this file `admin.yml`):
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If you want to try Garage on K8S, we currently only provide some basic [example files](https://git.deuxfleurs.fr/Deuxfleurs/garage/src/commit/7e1ac51b580afa8e900206e7cc49791ed0a00d94/script/k8s). These files register a [ConfigMap](https://kubernetes.io/docs/concepts/configuration/configmap/), a [ClusterRoleBinding](https://kubernetes.io/docs/reference/access-authn-authz/rbac/#rolebinding-and-clusterrolebinding), and a [StatefulSet](https://kubernetes.io/fr/docs/concepts/workloads/controllers/statefulset/) with a [Persistent Volumes](https://kubernetes.io/docs/concepts/storage/persistent-volumes/).
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```yaml
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apiVersion: rbac.authorization.k8s.io/v1
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kind: ClusterRoleBinding
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metadata:
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name: garage-admin
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roleRef:
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apiGroup: rbac.authorization.k8s.io
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kind: ClusterRole
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name: cluster-admin
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subjects:
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- apiGroup: rbac.authorization.k8s.io
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kind: User
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name: system:serviceaccount:default:default
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```
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Apply it:
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```bash
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kubectl apply -f admin.yaml
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```
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Finally, we create a [StatefulSet](https://kubernetes.io/fr/docs/concepts/workloads/controllers/statefulset/) to run our service (`service.yaml`):
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```yaml
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apiVersion: apps/v1
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kind: StatefulSet
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metadata:
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name: garage
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spec:
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selector:
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matchLabels:
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app: garage
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serviceName: "garage"
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replicas: 3
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template:
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metadata:
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labels:
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app: garage
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spec:
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terminationGracePeriodSeconds: 10
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containers:
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- name: garage
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image: dxflrs/amd64_garage:v0.7.0
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ports:
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- containerPort: 3900
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name: s3-api
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- containerPort: 3902
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name: web-api
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volumeMounts:
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- name: fast
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mountPath: /mnt/fast
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- name: slow
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mountPath: /mnt/slow
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- name: etc
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mountPath: /etc/garage.toml
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subPath: garage.toml
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volumes:
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- name: etc
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configMap:
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name: garage-config
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volumeClaimTemplates:
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- metadata:
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name: fast
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spec:
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accessModes: [ "ReadWriteOnce" ]
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resources:
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requests:
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storage: 100Mi
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- metadata:
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name: slow
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spec:
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accessModes: [ "ReadWriteOnce" ]
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resources:
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requests:
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storage: 100Mi
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```
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Garage is a stateful program, so it needs a stable place to store its data and metadata.
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This feature is provided by Kubernetes' [Persistent Volumes](https://kubernetes.io/docs/concepts/storage/persistent-volumes/) that can be used only from a [StatefulSet](https://kubernetes.io/fr/docs/concepts/workloads/controllers/statefulset/), hence the choice of this K8S object to deploy our service.
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Kubernetes has many "drivers" for Persistent Volumes, for production uses we recommend **only** the `local` driver.
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Using other drivers may lead to huge performance issues or data corruption, probably both in practice.
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In the example, we are claiming 2 volumes of 100MB.
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We use 2 volumes instead of 1 because Garage separates its metadata from its data.
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By having 2 volumes, you can reserve a smaller capacity on a SSD for the metadata and a larger capacity on a regular HDD for the data.
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Do not forget to change the reserved capacity, 100MB is only suitable for testing.
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*Note how we are mounting our ConfigMap: we need to set the `subpath` property to mount only the `garage.toml` file and not the whole `/etc` folder that would prevent K8S from writing its own files
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in `/etc` and fail the pod.*
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You can apply this file with:
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```bash
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kubectl apply -f service.yaml
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```
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Now, you are ready to interact with your cluster, each instance must have discovered the other ones:
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Once these files deployed, you will be able to interact with Garage as follow:
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```bash
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kubectl exec -it garage-0 --container garage -- /garage status
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# ==== HEALTHY NODES ====
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# ID Hostname Address Tags Zone Capacity
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# e6284331c321a23c garage-0 172.17.0.5:3901 NO ROLE ASSIGNED
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# 570ff9b0ed3648a7 garage-2 [::ffff:172.17.0.7]:3901 NO ROLE ASSIGNED
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# e1990a2069429428 garage-1 [::ffff:172.17.0.6]:3901 NO ROLE ASSIGNED
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# ID Hostname Address Tags Zone Capacity
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# e628.. garage-0 172.17.0.5:3901 NO ROLE ASSIGNED
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# 570f.. garage-2 172.17.0.7:3901 NO ROLE ASSIGNED
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# e199.. garage-1 172.17.0.6:3901 NO ROLE ASSIGNED
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```
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Of course, to have a full deployment, you will probably want to deploy a [Service](https://kubernetes.io/docs/concepts/services-networking/service/) in front of your cluster and/or a reverse proxy.
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You can then follow the [regular documentation](https://garagehq.deuxfleurs.fr/documentation/cookbook/real-world/#creating-a-cluster-layout) to complete the configuration of your cluster.
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If you target a production deployment, you should avoid binding admin rights to your cluster to create Garage's CRD. You will also need to expose some [Services](https://kubernetes.io/docs/concepts/services-networking/service/) to make your cluster reachable. Keep also in mind that Garage is a stateful service, so you must be very careful how you handle your data in Kubernetes to not lose them. In the near future, we plan to release a proper Helm chart and write "best practises" on our documentation.
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If Kubernetes is not your thing, know that we are running Garage on a Nomad+Consul cluster.
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We have not documented it yet but you can get a look at [our Nomad service](https://git.deuxfleurs.fr/Deuxfleurs/infrastructure/src/commit/1e5e4af35c073d04698bb10dd4ad1330d6c62a0d/app/garage/deploy/garage.hcl).
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@ -265,5 +134,8 @@ In all cases, your feedback is welcome on our Matrix channel.
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## Conclusion
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This is only the first iteration of the Kubernetes and OpenTelemetry into Garage, so things are still a bit rough.
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We plan to polish their integration in the coming months based on our experience and your feedback.
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You may also ask yourself what will be the other works we plan to conduct: stay tuned, we will release a roadmap soon!
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In the mean time, we hope you will enjoy Garave v0.7!
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