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Version: 3.8

Getting Started with Helm Charts (ScalarDB Cluster with TLS by Using cert-manager)

This tutorial explains how to get started with ScalarDB Cluster with TLS configurations by using Helm Charts and cert-manager on a Kubernetes cluster in a test environment. Before starting, you should already have a Mac or Linux environment for testing. In addition, although this tutorial mentions using minikube, the steps described should work in any Kubernetes cluster.

Requirements​

  • You need to have a license key (trial license or commercial license) for ScalarDB Cluster. If you don't have a license key, please contact us.
  • You need to use ScalarDB Cluster 3.12 or later, which supports TLS.

What you'll create​

In this tutorial, you'll deploy the following components on a Kubernetes cluster in the following way:

+----------------------------------------------------------------------------------------------------------------------------------------------------+
| [Kubernetes Cluster]                                                                                                                               |
|                                            [Pod]                                                      [Pod]                           [Pod]        |
|                                                                                                                                                    |
|                                          +-------+                                          +------------------------+                             |
|                                    +---> | Envoy | ---+                               +---> | ScalarDB Cluster node  | ---+                        |
|    [Pod]                           |     +-------+    |                               |     +------------------------+    |                        |
|                                    |                  |                               |                                   |                        |
|  +-----------+      +---------+    |     +-------+    |     +--------------------+    |     +------------------------+    |     +---------------+  |
|  |  Client   | ---> | Service | ---+---> | Envoy | ---+---> |  Service           | ---+---> | ScalarDB Cluster node  | ---+---> |  PostgreSQL   |  |
|  | (SQL CLI) |      | (Envoy) |    |     +-------+    |     | (ScalarDB Cluster) |    |     +------------------------+    |     | (For Ledger)  |  |
|  +-----------+      +---------+    |                  |     +--------------------+    |                                   |     +---------------+  |
|                                    |     +-------+    |                               |     +------------------------+    |                        |
|                                    +---> | Envoy | ---+                               +---> | ScalarDB Cluster node  | ---+                        |
|                                          +-------+                                          +------------------------+                             |
|                                                                                                                                                    |
|  +----------------------------------------------------------------------------------+    +---------------------+                                   |
|  | cert-manager (create private key and certificate for Envoy and ScalarDB Cluster) |    | Issuer (Private CA) |                                   |
|  +----------------------------------------------------------------------------------+    +---------------------+                                   |
|                                                                                                                                                    |
+----------------------------------------------------------------------------------------------------------------------------------------------------+

cert-manager automatically creates the following private key and certificate files for TLS connections.

                                                           +----------------------+
                                                     +---> | For Scalar Envoy     |
                                                     |     +----------------------+
                                                     |     | tls.key              |
                                                     |     | tls.crt              |
+-------------------------+                          |     +----------------------+
| Issuer (Self-signed CA) | ---(Sign certificates)---+
+-------------------------+                          |     +----------------------+
| tls.key                 |                          +---> | For ScalarDB Cluster |
| tls.crt                 |                                +----------------------+
| ca.crt                  |                                | tls.key              |
+-------------------------+                                | tls.crt              |
                                                           +----------------------+

Scalar Helm Charts automatically mount each private key and certificate file for Envoy and ScalarDB Cluster as follows to enable TLS in each connection. You'll manually mount a root CA certificate file on the client.

+-------------------------------------+                            +------------------------------------------------+      +--------------------------------+
| Client                              | ---(CRUD/SQL requests)---> | Envoy for ScalarDB Cluster                     | ---> | ScalarDB Cluster nodes         |
+-------------------------------------+                            +------------------------------------------------+      +--------------------------------+
| ca.crt (to verify tls.crt of Envoy) |                            | tls.key                                        |      | tls.key                        |
+-------------------------------------+                            | tls.crt                                        |      | tls.crt                        |
                                                                   | ca.crt (to verify tls.crt of ScalarDB Cluster) |      | ca.crt (to check health)       |
                                                                   +------------------------------------------------+      +--------------------------------+

The following connections exist amongst the ScalarDB Cluster–related components:

  • Client - Envoy for ScalarDB Cluster: When you execute a CRUD API or SQL API function, the client accesses Envoy for ScalarDB Cluster.
  • Envoy for ScalarDB Cluster - ScalarDB Cluster: Envoy works as an L7 (gRPC) load balancer in front of ScalarDB Cluster.
  • ScalarDB Cluster node - ScalarDB Cluster node: A ScalarDB Cluster node accesses other ScalarDB Cluster nodes. In other words, the cluster's internal communications exist amongst all ScalarDB Cluster nodes.

Step 1. Start a Kubernetes cluster and install tools​

You need to prepare a Kubernetes cluster and install some tools (kubectl, helm, cfssl, and cfssljson). For more details on how to install them, see Getting Started with Scalar Helm Charts.

Step 2. Start the PostgreSQL containers​

ScalarDB Cluster must use some type of database system as a backend database. In this tutorial, you'll use PostgreSQL.

You can deploy PostgreSQL on the Kubernetes cluster as follows:

  1. Add the Bitnami helm repository.

    helm repo add bitnami https://charts.bitnami.com/bitnami

  2. Deploy PostgreSQL for ScalarDB Cluster.

    helm install postgresql-scalardb-cluster bitnami/postgresql \
      --set auth.postgresPassword=postgres \
      --set primary.persistence.enabled=false \
      -n default

  3. Check if the PostgreSQL containers are running.

    kubectl get pod -n default

    [Command execution result]

    NAME                            READY   STATUS    RESTARTS   AGE
    postgresql-scalardb-cluster-0   1/1     Running   0          34s

Step 3. Create a working directory​

You'll create some configuration files locally. Be sure to create a working directory for those files.

  1. Create a working directory.

    mkdir -p ${HOME}/scalardb-cluster-test/

Step 4. Deploy cert-manager and issuer resource​

This tutorial uses cert-manager to issue and manage your private keys and certificates. You can deploy cert-manager on the Kubernetes cluster as follows:

  1. Add the Jetstack helm repository.

    helm repo add jetstack https://charts.jetstack.io

  2. Deploy cert-manager.

    helm install cert-manager jetstack/cert-manager \
      --create-namespace \
      --set installCRDs=true \
      -n cert-manager

  3. Check if the cert-manager containers are running.

    kubectl get pod -n cert-manager

    [Command execution result]

    NAME                                      READY   STATUS    RESTARTS   AGE
    cert-manager-6dc66985d4-6lvtt             1/1     Running   0          26s
    cert-manager-cainjector-c7d4dbdd9-xlrpn   1/1     Running   0          26s
    cert-manager-webhook-847d7676c9-ckcz2     1/1     Running   0          26s

  4. Change the working directory to ${HOME}/scalardb-cluster-test/.

    cd ${HOME}/scalardb-cluster-test/

  5. Create a custom values file for the private CA (private-ca-custom-values.yaml).

    cat << 'EOF' > ${HOME}/scalardb-cluster-test/private-ca-custom-values.yaml
    apiVersion: cert-manager.io/v1
    kind: Issuer
    metadata:
      name: self-signed-issuer
    spec:
      selfSigned: {}
    ---
    apiVersion: cert-manager.io/v1
    kind: Certificate
    metadata:
      name: self-signed-ca-cert
    spec:
      isCA: true
      commonName: self-signed-ca
      secretName: self-signed-ca-cert-secret
      privateKey:
        algorithm: ECDSA
        size: 256
      issuerRef:
        name: self-signed-issuer
        kind: Issuer
        group: cert-manager.io
    ---
    apiVersion: cert-manager.io/v1
    kind: Issuer
    metadata:
      name: self-signed-ca
    spec:
      ca:
        secretName: self-signed-ca-cert-secret
    EOF

  6. Deploy a self-signed CA.

    kubectl apply -f ./private-ca-custom-values.yaml

  7. Check if the issuer resources are True.

    kubectl get issuer

    [Command execution result]

    NAME                 READY   AGE
    self-signed-ca      True    6s
    self-signed-issuer   True    6s

Step 5. Deploy ScalarDB Cluster on the Kubernetes cluster by using Helm Charts​

  1. Add the Scalar Helm Charts repository.

    helm repo add scalar-labs https://scalar-labs.github.io/helm-charts

  2. Set your license key and certificate as environment variables. If you don't have a license key, please contact us. For details about the value of <CERT_PEM_FOR_YOUR_LICENSE_KEY>, see How to Configure a Product License Key.

    SCALAR_DB_CLUSTER_LICENSE_KEY='<YOUR_LICENSE_KEY>'
    SCALAR_DB_CLUSTER_LICENSE_CHECK_CERT_PEM='<CERT_PEM_FOR_YOUR_LICENSE_KEY>'

  3. Create a custom values file for ScalarDB Cluster (scalardb-cluster-custom-values.yaml).

    cat << 'EOF' > ${HOME}/scalardb-cluster-test/scalardb-cluster-custom-values.yaml
    envoy:

      enabled: true

      tls:
        downstream:
          enabled: true
          certManager:
            enabled: true
            issuerRef:
              name: self-signed-ca
            dnsNames:
              - envoy.scalar.example.com
        upstream:
          enabled: true
          overrideAuthority: "cluster.scalardb.example.com"

    scalardbCluster:

      image:
        repository: "ghcr.io/scalar-labs/scalardb-cluster-node-byol-premium"

      scalardbClusterNodeProperties: |
        ### Necessary configurations for deployment on Kuberetes
        scalar.db.cluster.membership.type=KUBERNETES
        scalar.db.cluster.membership.kubernetes.endpoint.namespace_name=${env:SCALAR_DB_CLUSTER_MEMBERSHIP_KUBERNETES_ENDPOINT_NAMESPACE_NAME}
        scalar.db.cluster.membership.kubernetes.endpoint.name=${env:SCALAR_DB_CLUSTER_MEMBERSHIP_KUBERNETES_ENDPOINT_NAME}

        ### Storage configurations
        scalar.db.contact_points=jdbc:postgresql://postgresql-scalardb-cluster.default.svc.cluster.local:5432/postgres
        scalar.db.username=${env:SCALAR_DB_CLUSTER_POSTGRES_USERNAME}
        scalar.db.password=${env:SCALAR_DB_CLUSTER_POSTGRES_PASSWORD}
        scalar.db.storage=jdbc

        ### SQL configurations
        scalar.db.sql.enabled=true

        ### Auth configurations
        scalar.db.cluster.auth.enabled=true
        scalar.db.cross_partition_scan.enabled=true

        ### TLS configurations
        scalar.db.cluster.tls.enabled=true
        scalar.db.cluster.tls.ca_root_cert_path=/tls/scalardb-cluster/certs/ca.crt
        scalar.db.cluster.node.tls.cert_chain_path=/tls/scalardb-cluster/certs/tls.crt
        scalar.db.cluster.node.tls.private_key_path=/tls/scalardb-cluster/certs/tls.key
        scalar.db.cluster.tls.override_authority=cluster.scalardb.example.com

        ### License key configurations
        scalar.db.cluster.node.licensing.license_key=${env:SCALAR_DB_CLUSTER_LICENSE_KEY}
        scalar.db.cluster.node.licensing.license_check_cert_pem=${env:SCALAR_DB_CLUSTER_LICENSE_CHECK_CERT_PEM}

      tls:
        enabled: true
        overrideAuthority: "cluster.scalardb.example.com"
        certManager:
          enabled: true
          issuerRef:
            name: self-signed-ca
          dnsNames:
            - cluster.scalardb.example.com

      secretName: "scalardb-credentials-secret"
    EOF

  4. Create a secret resource named scalardb-credentials-secret that includes credentials and license keys.

    kubectl create secret generic scalardb-credentials-secret \
    --from-literal=SCALAR_DB_CLUSTER_POSTGRES_USERNAME=postgres \
    --from-literal=SCALAR_DB_CLUSTER_POSTGRES_PASSWORD=postgres \
    --from-literal=SCALAR_DB_CLUSTER_LICENSE_KEY="${SCALAR_DB_CLUSTER_LICENSE_KEY}" \
    --from-file=SCALAR_DB_CLUSTER_LICENSE_CHECK_CERT_PEM=<(echo ${SCALAR_DB_CLUSTER_LICENSE_CHECK_CERT_PEM} | sed 's/\\n/\
    /g') \
    -n default

  5. Set the chart version of ScalarDB Cluster.

    SCALAR_DB_CLUSTER_VERSION=3.12.2
    SCALAR_DB_CLUSTER_CHART_VERSION=$(helm search repo scalar-labs/scalardb-cluster -l | grep -F "${SCALAR_DB_CLUSTER_VERSION}" | awk '{print $2}' | sort --version-sort -r | head -n 1)

  6. Deploy ScalarDB Cluster.

    helm install scalardb-cluster scalar-labs/scalardb-cluster -f ${HOME}/scalardb-cluster-test/scalardb-cluster-custom-values.yaml --version ${SCALAR_DB_CLUSTER_CHART_VERSION} -n default

  7. Check if the ScalarDB Cluster pods are deployed.

    kubectl get pod -n default

    [Command execution result]

    NAME                                     READY   STATUS    RESTARTS   AGE
    postgresql-scalardb-cluster-0            1/1     Running   0          4m30s
    scalardb-cluster-envoy-7cc948dfb-4rb8l   1/1     Running   0          18s
    scalardb-cluster-envoy-7cc948dfb-hwt96   1/1     Running   0          18s
    scalardb-cluster-envoy-7cc948dfb-rzbrx   1/1     Running   0          18s
    scalardb-cluster-node-7c6959c79d-445kj   1/1     Running   0          18s
    scalardb-cluster-node-7c6959c79d-4z54q   1/1     Running   0          18s
    scalardb-cluster-node-7c6959c79d-vcv96   1/1     Running   0          18s

    If the ScalarDB Cluster pods are deployed properly, the STATUS column for those pods will be displayed as Running.

  8. Check if the ScalarDB Cluster services are deployed.

    kubectl get svc -n default

    [Command execution result]

    NAME                             TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)     AGE
    kubernetes                       ClusterIP   10.96.0.1       <none>        443/TCP     7h34m
    postgresql-scalardb-cluster      ClusterIP   10.96.92.27     <none>        5432/TCP    4m52s
    postgresql-scalardb-cluster-hl   ClusterIP   None            <none>        5432/TCP    4m52s
    scalardb-cluster-envoy           ClusterIP   10.96.250.175   <none>        60053/TCP   40s
    scalardb-cluster-envoy-metrics   ClusterIP   10.96.40.197    <none>        9001/TCP    40s
    scalardb-cluster-headless        ClusterIP   None            <none>        60053/TCP   40s
    scalardb-cluster-metrics         ClusterIP   10.96.199.135   <none>        9080/TCP    40s

    If the ScalarDB Cluster services are deployed properly, you can see private IP addresses in the CLUSTER-IP column.

note

The CLUSTER-IP values for postgresql-scalardb-cluster-hl and scalardb-cluster-headless are None since they have no IP addresses.

Step 6. Start a client container​

You'll use the CA certificate file in a client container. Therefore, you'll need to create a secret resource and mount it to the client container.

  1. Create a secret resource named client-ca-cert.

    kubectl create secret generic client-ca-cert --from-file=ca.crt=<(kubectl get secret self-signed-ca-cert-secret -o "jsonpath={.data['ca\.crt']}" | base64 -d) -n default

  2. Create a manifest file for a client pod (scalardb-cluster-client-pod.yaml).

    cat << 'EOF' > ${HOME}/scalardb-cluster-test/scalardb-cluster-client-pod.yaml
    apiVersion: v1
    kind: Pod
    metadata:
      name: "scalardb-cluster-client"
    spec:
      containers:
        - name: scalardb-cluster-client
          image: eclipse-temurin:8-jre-jammy
          command: ['sleep']
          args: ['inf']
          env:
            - name: SCALAR_DB_CLUSTER_VERSION
              value: SCALAR_DB_CLUSTER_CLIENT_POD_SCALAR_DB_CLUSTER_VERSION
          volumeMounts:
            - name: "client-ca-cert"
              mountPath: "/certs/"
              readOnly: true
      volumes:
        - name: "client-ca-cert"
          secret:
            secretName: "client-ca-cert"
      restartPolicy: Never
    EOF

  3. Set the ScalarDB Cluster version in the manifest file.

    sed -i s/SCALAR_DB_CLUSTER_CLIENT_POD_SCALAR_DB_CLUSTER_VERSION/${SCALAR_DB_CLUSTER_VERSION}/ ${HOME}/scalardb-cluster-test/scalardb-cluster-client-pod.yaml

  4. Deploy the client pod.

    kubectl apply -f ${HOME}/scalardb-cluster-test/scalardb-cluster-client-pod.yaml -n default

  5. Check if the client container is running.

    kubectl get pod scalardb-cluster-client -n default

    [Command execution result]

    NAME                      READY   STATUS    RESTARTS   AGE
    scalardb-cluster-client   1/1     Running   0          26s

Step 7. Run the ScalarDB Cluster SQL CLI in the client container​

  1. Run bash in the client container.

    kubectl exec -it scalardb-cluster-client -n default -- bash

    The commands in the following steps must be run in the client container.

  2. Download the ScalarDB Cluster SQL CLI from Releases.

    curl -OL https://github.com/scalar-labs/scalardb/releases/download/v${SCALAR_DB_CLUSTER_VERSION}/scalardb-cluster-sql-cli-${SCALAR_DB_CLUSTER_VERSION}-all.jar

  3. Create a database.properties file and add configurations.

    cat << 'EOF' > /database.properties
    # ScalarDB Cluster configurations
    scalar.db.sql.connection_mode=cluster
    scalar.db.sql.cluster_mode.contact_points=indirect:scalardb-cluster-envoy.default.svc.cluster.local

    # Auth configurations
    scalar.db.cluster.auth.enabled=true
    scalar.db.sql.cluster_mode.username=admin
    scalar.db.sql.cluster_mode.password=admin

    # TLS configurations
    scalar.db.cluster.tls.enabled=true
    scalar.db.cluster.tls.ca_root_cert_path=/certs/ca.crt
    scalar.db.cluster.tls.override_authority=envoy.scalar.example.com
    EOF

  4. Run the ScalarDB Cluster SQL CLI.

    java -jar /scalardb-cluster-sql-cli-${SCALAR_DB_CLUSTER_VERSION}-all.jar --config /database.properties

  5. Create a sample namespace named ns.

    CREATE NAMESPACE ns;

  6. Create a sample table named tbl under the namespace ns.

    CREATE TABLE ns.tbl (a INT, b INT, c INT, PRIMARY KEY(a, b));

  7. Insert sample records.

    INSERT INTO ns.tbl VALUES (1,2,3), (4,5,6), (7,8,9);

  8. Select the sample records that you inserted.

    SELECT * FROM ns.tbl;

    [Command execution result]

    0: scalardb> SELECT * FROM ns.tbl;
    +---+---+---+
    | a | b | c |
    +---+---+---+
    | 7 | 8 | 9 |
    | 1 | 2 | 3 |
    | 4 | 5 | 6 |
    +---+---+---+
    3 rows selected (0.059 seconds)

  9. Press Ctrl + D to exit from ScalarDB Cluster SQL CLI.

    ^D

  10. Exit from the client container.

    exit

Step 8. Delete all resources​

After completing the ScalarDB Cluster tests on the Kubernetes cluster, remove all resources.

  1. Uninstall ScalarDB Cluster and PostgreSQL.

    helm uninstall -n default scalardb-cluster postgresql-scalardb-cluster

  2. Remove the self-signed CA.

    kubectl delete -f ./private-ca-custom-values.yaml

  3. Uninstall cert-manager.

    helm uninstall -n cert-manager cert-manager

  4. Remove the client container.

    kubectl delete pod scalardb-cluster-client --grace-period 0 -n default

  5. Remove the secret resources.

    kubectl delete secrets scalardb-credentials-secret self-signed-ca-cert-secret scalardb-cluster-envoy-tls-cert scalardb-cluster-tls-cert client-ca-cert

  6. Remove the namespace cert-manager.

    kubectl delete ns cert-manager

  7. Remove the working directory and the sample configuration files.

    cd ${HOME}
    rm -rf ${HOME}/scalardb-cluster-test/

Further reading​

You can see how to get started with monitoring or logging for Scalar products in the following tutorials: