docs/source/includes/k8s/deploy-operator.rst

Deploy the MinIO Operator

minio

Table of Contents

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 () of the MinIO Operator and MinIO Plugin on Kubernetes infrastructure:

• The MinIO Operator installs a Custom Resource Definition (CRD) <concepts/extend-kubernetes/api-extension/custom-resources/#customresourcedefinitions> to support describing MinIO tenants as a Kubernetes object <concepts/overview/working-with-objects/kubernetes-objects/>. See the MinIO Operator CRD Reference <operator/blob/master/docs/tenant_crd.adoc> for complete documentation on the MinIO CRD.
• The MinIO Kubernetes Plugin brings native support for deploying and managing MinIO tenants on a Kubernetes cluster using the kubectl minio command.

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.

Within the Operator's namespace, the MinIO Operator utilizes two pods: - The Operator pod for the base Operator functions to deploy, manage, modify, and maintain tenants. - Console pod for the Operator's Graphical User Interface, the Operator Console.

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 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 that monitors configuration secrets for the tenant and updates them as they change. This container also monitors for root credentials and creates an error if it does not find root credentials.

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

Prerequisites

Kubernetes Version 1.19.0

Starting with v4.0.0, the MinIO Operator and MinIO Kubernetes Plugin require Kubernetes 1.19.0 and later. The Kubernetes infrastructure and the kubectl CLI tool must have the same version of 1.19.0+.

Prior to v4.0.0, the MinIO Operator and Plugin required Kubernetes 1.17.0. You must upgrade your Kubernetes infrastructure to 1.19.0 or later to use the MinIO Operator or Plugin v4.0.0 or later.

Starting with v5.0.0, MinIO recommends Kubernetes 1.21.0 or later for both the infrastructure and the kubectl CLI tool.

Operator 5.0.6

For Kubernetes 1.25.0 and later, MinIO supports deploying in environments with the Pod Security admission (PSA) <concepts/security/pod-security-admission> restricted policy enabled.

kubectl Configuration

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

Kubernetes TLS Certificate API

Operator v.5.0.0

The MinIO Operator manages TLS Certificate Signing Requests (CSR) using the Kubernetes certificates.k8s.io TLS certificate management API <tasks/tls/managing-tls-in-a-cluster/> to create signed TLS certificates in the following circumstances:

• When autoCert is enabled.
• For the MinIO Console when the OPERATOR_CONSOLE_TLS_ENABLE environment variable is set to on.
• For STS service <minio-security-token-service> when OPERATOR_STS_ENABLED environment variable is set to on.
• For retrieving the health of the cluster.

The MinIO Operator reads certificates inside the operator-ca-tls secret and syncs this secret within the tenant namespace to trust private certificate authorities, such as when using cert-manager.

For any of these circumstances, the MinIO Operator requires that the Kubernetes kube-controller-manager configuration include the following configuration settings <reference/command-line-tools-reference/kube-controller-manager/#options>:

• --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 <7748>) TLS private keys/certificates due to their lower computation requirements compared to RSA. See minio-TLS-supported-cipher-suites for a complete list of supported TLS Cipher Suites.

If the Kubernetes cluster is not configured to respond to a generated CSR (Certificate Signing Request), 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 minio-tls for more complete documentation.

Configure MinIO Operator to Trust Custom Certificates

If you use custom certificates for your deployment, add the certificate so that MinIO Operator trusts it.

This procedure assumes you have an existing custom certificate.

1. Use the following command to generate a secret from the certificate:

   kubectl create secret generic MY-CUSTOM-TLS -n MY-CLUSTER-NAMESPACE --from-file=<path/to/public.crt>

   Replace the following placeholders in the above command:

   • MY-CUSTOM-TLS with the name of your secrets file
   • MY-CLUSTER-NAMESPACE with your cluster's namespace
   • <path/to/public.crt> with the relative path to the public certificate to use to create the secret

2. Add a volume to the yaml for your cluster under .spec.template.spec

   volumes:
     - name: tls-certificates
       projected:
         defaultMode: 420
         sources:
           - secret:
               items:
                 - key: public.crt
                   path: CAs/custom-public.crt
               name: MY-CUSTOM-TLS

   • replace MY-CUSTOM-TLS with the name of your secrets file.

3. Add a volumeMount to the yaml for your cluster under .spec.template.spec.container[0]

   volumeMounts:
     - mountPath: /tmp/certs
       name: tls-certificates

Procedure

The following steps deploy Operator using the MinIO Kubernetes Plugin. To install Operator using a Helm chart, see Deploy Operator with Helm <minio-k8s-deploy-operator-helm>.

/operations/install-deploy-manage/deploy-operator-helm