Deploy the MinIO Operator

Overview

MinIO is a Kubernetes-native high performance object store with an S3-compatible API. The MinIO Kubernetes Operator supports deploying MinIO Tenants onto private and public cloud infrastructures (“Hybrid” Cloud).

The following procedure installs the latest stable version (6.0.4) of the MinIO Operator on Kubernetes infrastructure.

The MinIO Operator installs a Custom Resource Definition (CRD) to support describing MinIO tenants as a Kubernetes object. See the MinIO Operator CRD Reference for complete documentation on the MinIO CRD.

This documentation assumes familiarity with referenced Kubernetes concepts, utilities, and procedures. While this documentation may provide guidance for configuring or deploying Kubernetes-related resources on a best-effort basis, it is not a replacement for the official Kubernetes Documentation.

MinIO Operator Components

The MinIO Operator exists in its own namespace in which it creates Kubernetes resources. Those resources includes pods, services, replicasets, and deployments.

The Operator pods monitor all namespaces by default for objects using the MinIO CRD and manages those resources automatically.

When you use the Operator to create a tenant, the tenant must have its own namespace. Within that namespace, the Operator generates the pods required by the tenant configuration.

Each Tenant pod runs three containers:

MinIO Container that runs all of the standard MinIO functions, equivalent to basic MinIO installation on baremetal. This container stores and retrieves objects in the provided mount points (persistent volumes).
InitContainer that only exists during the launch of the pod to manage configuration secrets during startup. Once startup completes, this container terminates.
Sidecar container used to initialize the MinIO tenant. The sidecar retrieves and validates the configuration for each tenant and creates the necessary local resources in the pod.

Changed in version Operator: 6.0.0

The Sidecar has its own image and release cycle separate from the rest of the MinIO Operator. The MinIO Operator stores the tenant’s environment variables in the sidecar, allowing the Operator to update the variables without requiring a rolling restart.

The tenant utilizes Persistent Volume Claims to talk to the Persistent Volumes that store the objects.

Prerequisites

Kubernetes Version v1.28.9

MinIO tests 6.0.4 against a floor of Kubernetes API of v1.28.9. MinIO strongly recommends maintaining Kubernetes infrastructure using actively maintained Kubernetes API versions.

MinIO strongly recommends upgrading Kubernetes clusters running with End-Of-Life API versions

Kustomize and `kubectl`

Kustomize is a YAML-based templating tool that allows you to define Kubernetes resources in a declarative and repeatable fashion. Kustomize is included with the kubectl command line tool.

This procedure assumes that your local host machine has both the matching version of kubectl for your Kubernetes cluster and the necessary access to that cluster to create new resources.

The default MinIO Operator Kustomize template provides a starting point for customizing configurations for your local environment. You can modify the default Kustomization file or apply your own patches to customize the Operator deployment for your Kubernetes cluster.

Kubernetes TLS Certificate API

Changed in version Operator: v.5.0.0

The MinIO Operator manages TLS Certificate Signing Requests (CSR) using the Kubernetes certificates.k8s.io TLS certificate management API to create signed TLS certificates in the following circumstances:

When autoCert is enabled.
For the MinIO Tenant Console when the MINIO_CONSOLE_TLS_ENABLE environment variable is set to on.
For STS service when OPERATOR_STS_ENABLED environment variable is set to on.
For retrieving the health of the cluster.

Beginning with Operator 6.0.0, the MinIO Operator reads certificates inside the operator-ca-tls secret to trust private certificate authorities throughout the Kubernetes cluster, such as when using cert-manager. Previous versions of the Operator sync the operator-ca-tls certificates to each tenant.

For any of these circumstances, the MinIO Operator requires that the Kubernetes kube-controller-manager configuration include the following configuration settings:

--cluster-signing-key-file - Specify the PEM-encoded RSA or ECDSA private key used to sign cluster-scoped certificates.
--cluster-signing-cert-file - Specify the PEM-encoded x.509 Certificate Authority certificate used to issue cluster-scoped certificates.

The Kubernetes TLS API uses the CA signature algorithm for generating new TLS certificate. MinIO recommends ECDSA (e.g. NIST P-256 curve) or EdDSA (e.g. Curve25519) TLS private keys/certificates due to their lower computation requirements compared to RSA. See Supported TLS Cipher Suites for a complete list of supported TLS Cipher Suites.

If the Kubernetes cluster is not configured to respond to a generated CSR, the Operator cannot complete initialization. Some Kubernetes providers do not specify these configuration values by default.

To check whether the kube-controller-manager specifies the cluster signing key and certificate files, use the following command:

kubectl get pod kube-controller-manager-$CLUSTERNAME-control-plane \
  -n kube-system -o yaml

Replace $CLUSTERNAME with the name of the Kubernetes cluster.

Confirm that the output contains the highlighted lines. The output of the example command above may differ from the output in your terminal:

 spec:
 containers:
 - command:
     - kube-controller-manager
     - --allocate-node-cidrs=true
     - --authentication-kubeconfig=/etc/kubernetes/controller-manager.conf
     - --authorization-kubeconfig=/etc/kubernetes/controller-manager.conf
     - --bind-address=127.0.0.1
     - --client-ca-file=/etc/kubernetes/pki/ca.crt
     - --cluster-cidr=10.244.0.0/16
     - --cluster-name=my-cluster-name
     - --cluster-signing-cert-file=/etc/kubernetes/pki/ca.crt
     - --cluster-signing-key-file=/etc/kubernetes/pki/ca.key
 ...

Important

The MinIO Operator automatically generates TLS certificates for all MinIO Tenant pods using the specified Certificate Authority (CA). Clients external to the Kubernetes cluster must trust the Kubernetes cluster CA to connect to the MinIO Operator or MinIO Tenants.

Clients which cannot trust the Kubernetes cluster CA can disable TLS validation for connections to the MinIO Operator or a MinIO Tenant.

Alternatively, you can generate x.509 TLS certificates signed by a known and trusted CA and pass those certificates to MinIO Tenants. See Network Encryption (TLS) for more complete documentation.

Certificate Management with cert-manager

Rather than the MinIO Operator managing certificates, you can configure the deployment to use cert-manager. For instructions for deploying the MinIO Operator and tenants using cert-manager, refer to the cert-manager page.

Procedure

The following steps deploy Operator using Kustomize and a kustomization.yaml file from the MinIO Operator GitHub repository. To install Operator using a Helm chart, see Deploy Operator with Helm.

Install the MinIO Operator using Kustomize

The following procedure uses kubectl -k to install the Operator from the MinIO Operator GitHub repository. kubectl -k and kubectl --kustomize are aliases that perform the same command.

Important

If you use Kustomize to install the Operator, you must use Kustomize to manage or upgrade that installation. Do not use kubectl krew, a Helm chart, or similar methods to manage or upgrade a MinIO Operator installation deployed with Kustomize.

You can, however, use Kustomize to upgrade a previous version of Operator (5.0.14 or earlier) installed with the MinIO Kubernetes Plugin.

Install the latest version of Operator

The following command installs the Operator to the minio-operator namespace:
```
kubectl apply -k "github.com/minio/operator?ref=v6.0.4"
```
The command outputs a list of installed resources.

Verify the Operator pods are running:

kubectl get pods -n minio-operator

The output resembles the following:

NAME                              READY   STATUS              RESTARTS   AGE
minio-operator-6c758b8c45-nkhlx   1/1     Running   0          2m42s
minio-operator-6c758b8c45-dgd8n   1/1     Running   0          2m42s

In this example, the minio-operator pod is MinIO Operator and the console pod is the Operator Console.

You can modify your Operator deployment by applying kubectl patches. You can find examples for common configurations in the Operator GitHub repository.

Verify the Operator installation

Check the contents of the specified namespace (minio-operator) to ensure all pods and services have started successfully.

kubectl get all -n minio-operator

The response should resemble the following:

NAME                                  READY   STATUS    RESTARTS   AGE
pod/minio-operator-6c758b8c45-nkhlx   1/1     Running   0          5m20s
pod/minio-operator-6c758b8c45-dgd8n   1/1     Running   0          5m20s

NAME               TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                         AGE
service/operator   ClusterIP   10.43.135.241   <none>        4221/TCP                        5m20s
service/sts        ClusterIP   10.43.117.251   <none>        4223/TCP                        5m20s

NAME                             READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/minio-operator   2/2     2            2           5m20s

NAME                                        DESIRED   CURRENT   READY   AGE
replicaset.apps/minio-operator-6c758b8c45   2         2         2       5m20s

Next Steps

You can deploy MinIO tenants using the MinIO CRD and Kustomize. MinIO also provides a Helm chart for deploying Tenants.

MinIO recommends using the same method of Tenant deployment and management used to install the Operator. Mixing Kustomize and Helm for Operator or Tenant management may increase operational complexity.