Prepare the Kubernetes cluster

To prepare the Kubernetes cluster, perform the following tasks:

  1. Create a namespace.
  2. Install cert-manager.
  3. Install Linkerd.
  4. Configure storage classes.
  5. Create the Docker registry secret.
  6. Install the Obcerv Operator.

Create a namespace

Create or choose an existing namespace where you will install Obcerv.

kubectl create namespace itrs

Multiple instances of Obcerv can be installed in the same cluster, however there can only be one Obcerv instance in a namespace.

Install cert-manager

The Obcerv Operator installs an admission webhook that requires a TLS certificate.

Obcerv can use cert-manager to automatically generate TLS certificates required by some Obcerv components, including the Obcerv Operator.

Note

Although self-signed certificates are not recommended in production for encrypting externally facing connections, the Obcerv Operator’s admission webhook is an internal component that can use self-signed certificates without it being considered a security issue.

Unless your organization operates under security policies that strictly forbid self-signed certificates, you can use cert-manager for your Obcerv Operator’s webhook.

To install cert-manager, run:

helm repo add jetstack https://charts.jetstack.io
helm install cert-manager jetstack/cert-manager --set installCRDs=true -n itrs --wait

Alternatively, you can manually create TLS certificates for the Obcerv Operator’s webhook.

Manually create TLS certificates for the Obcerv Operator’s webhook

Using cert-manager automates the process of creating TLS certificates and is the recommended approach for the Obcerv Operator’s webhook. Optionally, you can choose to manually create and configure a certificate by performing the following steps:

  1. Determine the following before generating your keys, certificates and Kubernetes Secrets:

    • Namespace where you will be installing the Obcerv Operator, referred to as <%namespace%> in following instructions.
    • Name of the Obcerv Operator instance, referred to as <%instance-name%> in following instructions.
    • Password you will use to protect the pkcs12 file, referred to as <%password%> in following instructions.
    • Name of the pkcs12 keystore file, referred to as <%keystore-name%> in following instructions.

  2. Use your Certificate Authority (CA) to generate an RSA private key for your webhook server.

  3. Generate a Certificate Signing Request (CSR), incorporating the fully qualified webhook service name "/CN=<%instance-name%>-webhook.<%namespace%>.svc", for the webhook private key, and sign it with the private key of the CA.

  4. Generate a pkcs12 bundle containing the webhook server key and certificate, protected with a password.

  5. Create a Kubernetes Secret containing the pkcs12 file. This secret should be prefixed with the name of the Obcerv Operator instance:

    kubectl create secret generic <%instance-name%>-webhook-tls --from-file=<%keystore-name%>=keystore.p12

  6. Create a Kubernetes Secret containing the password for the pkcs12 file. This secret should be prefixed with the name of the Obcerv Operator instance:

    kubectl create secret generic <%instance-name%>-webhook-tls-password --from-literal=password='<%password%>'

  7. Obtain the base64 encoded value of the certificate that signed the pkcs12 file and use the output as the caCertificate in your Helm values file.

    cat ca.crt | base64
...
webhook.tls.caCertificate: <%...output from previous command...%>

Note

The value for the caCertification must be on a single line with no carriage returns.
  1. Set the following Helm values: 
    webhook:
  tls:
    selfSigned: false

    # Default secret name containing customer provided pkcs12 file loaded in a secret.
    keystoreSecret: "<%instance-name%>-webhook-tls"

    # Default name of the pkcs12 file inside the above secret
    keystoreSecretKey: "<%keystore-name%>" #defaults to "keystore.p12"

    # Password used when generating the pkcs12 file.
    keystorePasswordSecret: "<%instance-name%>-webhook-tls-password"

    # Base64 encoded value of the CA certificate that signed the certification for the webhook server.
    caCertificate: ""

Note

If you encounter errors installing the operator after manually configuring TLS certificates, consult the Troubleshooting steps.

Install Linkerd

Linkerd is used to enable mutual TLS between the Obcerv components. TLS inside the cluster is optional and is enabled by default.

However, in a testing or proof of concept deployment you may wish to disable TLS. In this case Linkerd is not required.

Linkerd is installed in its own linkerd namespace by default.

Optional installation flags:

Note

If your Kubernetes cluster is version 1.25 or later, you must use Linkerd version 2.12.2 or later.

Install:

linkerd install --crds | kubectl apply -f -

linkerd install | kubectl apply -f -

Ensure all components are installed before continuing:

linkerd check

Note

The linkerd install will generate certificates using a trust anchor with a validity of 365 days by default. See the Maintenance section for steps on how to manually rotate these prior to expiry.

Configure storage classes

Most Kubernetes clusters come with a default StorageClass pre-installed. This default StorageClass should be similar to general purpose SSD volumes on most cloud providers, such as the gp3 EBS volumes on AWS. This storage class should be configured with the default minimum gp3 settings of 3000 IOPS and 125 MiB/s throughput. For example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: gp3
provisioner: kubernetes.io/aws-ebs
parameters:
  type: "gp3"
  fsType: "ext4"
  iops: "3000"
  throughput: "125"
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true

Additionally, the Timescale workload may require higher-performing disks, specifically for large installations. These should also be similar to general purpose SSD volumes on most cloud providers, but should be configured with higher performance settings of 5000 IOPS and 200 MiB/s throughput. For example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: gp3-timescale
provisioner: kubernetes.io/aws-ebs
parameters:
  type: "gp3"
  fsType: "ext4"
  iops: "5000"
  throughput: "200"
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true

We strongly recommend using storage classes that support automatic volume expansion so that volumes can be expanded to accommodate growth without significant downtime. We recommend against using local persistent volumes in production environments – they are viable only on single-node clusters and some persistence features that Obcerv depends on are not supported.

Create the Docker registry secret

By default, Kubernetes pulls Obcerv Docker images from our Docker registry. In order to authenticate, you must create a Secret with your ITRS credentials:

kubectl create secret docker-registry itrsdocker \
  --docker-server=https://docker.itrsgroup.com \
  --docker-username=<USERNAME> \
  --docker-password=<PASSWORD> \
  -n itrs

However, if you have elected to use an intermediary Docker registry:

Note

Contact your ITRS representative if you do not have the required credentials.

Install the Obcerv Operator

The operator can be installed once per cluster (watching all namespaces) or once for a subset of namespaces. By default, the operator will watch only the namespace into which it is installed.

Add or update the ITRS Helm repository:

helm repo add itrs https://helm.itrsgroup.com
helm repo update

Install with the default settings:

helm install obcerv-operator itrs/obcerv-operator --version 1.5.1 -n itrs --wait

If using a private docker repository, then append --set docker.registry=<your-registry>/obcerv to the above command.

To override the list of watched namespaces, append this to the above command:

# All namespaces
--set "namespaces="

# Specific namespace(s)
--set "namespaces={ns1,ns2}"
["Obcerv"] ["User Guide", "Technical Reference"]

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