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
         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:

• Getting Started with Helm Charts (Monitoring using Prometheus Operator)
• Getting Started with Helm Charts (Logging using Loki Stack)
• Getting Started with Helm Charts (Scalar Manager)