This document explains how to get started with ScalarDL Ledger using Helm Chart on a Kubernetes cluster as a test environment. Here, we assume that you already have a Mac or Linux environment for testing. We use Minikube in this document, but the steps we will show should work in any Kubernetes cluster.

Requirement

You need to subscribe to ScalarDL Ledger in the AWS Marketplace or Azure Marketplace to get the following container images.

  • AWS Marketplace
    • scalar-ledger
    • scalar-ledger-envoy
    • scalardl-schema-loader-ledger
  • Azure Marketplace
    • scalar-ledger
    • scalardl-envoy
    • scalardl-schema-loader

Please refer to the following documents for more details.

What we create

We will deploy the following components on a Kubernetes cluster as follows.

+--------------------------------------------------------------------------------------------------------------------------------------+
| [Kubernetes Cluster]                                                                                                                 |
|                                                                                                                                      |
|    [Pod]                                [Pod]                                                  [Pod]                     [Pod]       |
|                                                                                                                                      |
|                                       +-------+                                         +-----------------+                          |
|                                 +---> | Envoy | ---+                              +---> | ScalarDL Ledger | ---+                     |
|                                 |     +-------+    |                              |     +-----------------+    |                     |
|                                 |                  |                              |                            |                     |
|  +--------+      +---------+    |     +-------+    |     +-------------------+    |     +-----------------+    |     +------------+  |
|  | Client | ---> | Service | ---+---> | Envoy | ---+---> |      Service      | ---+---> | ScalarDL Ledger | ---+---> | PostgreSQL |  |
|  +--------+      | (Envoy) |    |     +-------+    |     | (ScalarDL Ledger) |    |     +-----------------+    |     +------------+  |
|                  +---------+    |                  |     +-------------------+    |                            |                     |
|                                 |     +-------+    |                              |     +-----------------+    |                     |
|                                 +---> | Envoy | ---+                              +---> | ScalarDL Ledger | ---+                     |
|                                       +-------+                                         +-----------------+                          |
|                                                                                                                                      |
+--------------------------------------------------------------------------------------------------------------------------------------+

Step 1. Start a Kubernetes cluster

First, you need to prepare a Kubernetes cluster. If you use a minikube environment, please refer to the Getting Started with Scalar Helm Charts. If you have already started a Kubernetes cluster, you can skip this step.

Step 2. Start a PostgreSQL container

ScalarDL Ledger uses some kind of database system as a backend database. In this document, we 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.
    helm install postgresql-ledger bitnami/postgresql \
      --set auth.postgresPassword=postgres \
      --set primary.persistence.enabled=false
    
  3. Check if the PostgreSQL container is running.
    kubectl get pod
    

    [Command execution result]

    NAME                  READY   STATUS    RESTARTS   AGE
    postgresql-ledger-0   1/1     Running   0          11s
    

Step 3. Create a working directory

We will create some configuration files and key/certificate files locally. So, create a working directory for them.

  1. Create a working directory.
    mkdir -p ~/scalardl-test/certs/
    

Step 4. Create key/certificate files

Note: In this guide, we will use self-sign certificates for the test. However, it is strongly recommended that these certificates NOT be used in production.

  1. Change the working directory to ~/scalardl-test/certs/ directory.
    cd ~/scalardl-test/certs/
    
  2. Create a JSON file that includes Ledger information.
    cat << 'EOF' > ~/scalardl-test/certs/ledger.json
    {
        "CN": "ledger",
        "hosts": ["example.com","*.example.com"],
        "key": {
            "algo": "ecdsa",
            "size": 256
        },
        "names": [
            {
                "O": "ledger",
                "OU": "test team",
                "L": "Shinjuku",
                "ST": "Tokyo",
                "C": "JP"
            }
        ]
    }
    EOF
    
  3. Create a JSON file that includes Client information.
    cat << 'EOF' > ~/scalardl-test/certs/client.json
    {
        "CN": "client",
        "hosts": ["example.com","*.example.com"],
        "key": {
            "algo": "ecdsa",
            "size": 256
        },
        "names": [
            {
                "O": "client",
                "OU": "test team",
                "L": "Shinjuku",
                "ST": "Tokyo",
                "C": "JP"
            }
        ]
    }
    EOF
    
  4. Create key/certificate files for the Ledger.
    cfssl selfsign "" ./ledger.json | cfssljson -bare ledger
    
  5. Create key/certificate files for the Client.
    cfssl selfsign "" ./client.json | cfssljson -bare client
    
  6. Confirm key/certificate files are created.
    ls -1
    

    [Command execution result]

    client-key.pem
    client.csr
    client.json
    client.pem
    ledger-key.pem
    ledger.csr
    ledger.json
    ledger.pem
    

Step 5. Create DB schemas for ScalarDL Ledger using Helm Charts

We will deploy a ScalarDL Schema Loader on the Kubernetes cluster using Helm Charts.
The ScalarDL Schema Loader will create the DB schemas for ScalarDL Ledger in PostgreSQL.

  1. Change the working directory to ~/scalardl-test/.
    cd ~/scalardl-test/
    
  2. Add the Scalar helm repository.
    helm repo add scalar-labs https://scalar-labs.github.io/helm-charts
    
  3. Create a secret resource to pull the ScalarDL container images from AWS/Azure Marketplace.
    • AWS Marketplace
      kubectl create secret docker-registry reg-ecr-mp-secrets \
        --docker-server=709825985650.dkr.ecr.us-east-1.amazonaws.com \
        --docker-username=AWS \
        --docker-password=$(aws ecr get-login-password --region us-east-1)
      
    • Azure Marketplace
      kubectl create secret docker-registry reg-acr-secrets \
        --docker-server=<your private container registry login server> \
        --docker-username=<Service principal ID> \
        --docker-password=<Service principal password>
      

    Please refer to the following documents for more details.

  4. Create a custom values file for ScalarDL Schema Loader (schema-loader-ledger-custom-values.yaml).
    • AWS Marketplace

      cat << 'EOF' > ~/scalardl-test/schema-loader-ledger-custom-values.yaml
      schemaLoading:
        schemaType: "ledger"
        image:
          repository: "709825985650.dkr.ecr.us-east-1.amazonaws.com/scalar/scalardl-schema-loader-ledger"
          version: "3.6.0"
        imagePullSecrets:
          - name: "reg-ecr-mp-secrets"
        databaseProperties: |
          scalar.db.contact_points=jdbc:postgresql://postgresql-ledger.default.svc.cluster.local:5432/postgres
          scalar.db.username={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_USERNAME "" }}
          scalar.db.password={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_PASSWORD "" }}
          scalar.db.storage=jdbc
        secretName: "ledger-credentials-secret"
      EOF
      
    • Azure Marketplace

      cat << 'EOF' > ~/scalardl-test/schema-loader-ledger-custom-values.yaml
      schemaLoading:
        schemaType: "ledger"
        image:
          repository: "<your private container registry>/scalarinc/scalardl-schema-loader"
          version: "3.6.0"
        imagePullSecrets:
          - name: "reg-acr-secrets"
        databaseProperties: |
          scalar.db.contact_points=jdbc:postgresql://postgresql-ledger.default.svc.cluster.local:5432/postgres
          scalar.db.username={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_USERNAME "" }}
          scalar.db.password={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_PASSWORD "" }}
          scalar.db.storage=jdbc
        secretName: "ledger-credentials-secret"
      EOF
      
  5. Create a secret resource that includes a username and password for PostgreSQL.
    kubectl create secret generic ledger-credentials-secret \
      --from-literal=SCALAR_DL_LEDGER_POSTGRES_USERNAME=postgres \
      --from-literal=SCALAR_DL_LEDGER_POSTGRES_PASSWORD=postgres
    
  6. Deploy the ScalarDL Schema Loader.
    helm install schema-loader-ledger scalar-labs/schema-loading -f ./schema-loader-ledger-custom-values.yaml
    
  7. Check if the ScalarDL Schema Loader pod is deployed and completed.
    kubectl get pod
    

    [Command execution result]

    NAME                                        READY   STATUS      RESTARTS   AGE
    postgresql-ledger-0                         1/1     Running     0          11m
    schema-loader-ledger-schema-loading-46rcr   0/1     Completed   0          3s
    

    If the ScalarDL Schema Loader pod is ContainerCreating or Running, wait for the process will be completed (The STATUS will be Completed).

Step 6. Deploy ScalarDL Ledger on the Kubernetes cluster using Helm Charts

  1. Create a custom values file for ScalarDL Ledger (scalardl-ledger-custom-values.yaml).
    • AWS Marketplace

      cat << 'EOF' > ~/scalardl-test/scalardl-ledger-custom-values.yaml
      envoy:
        image:
          repository: "709825985650.dkr.ecr.us-east-1.amazonaws.com/scalar/scalar-ledger-envoy"
          version: "1.3.0"
        imagePullSecrets:
          - name: "reg-ecr-mp-secrets"
           
      ledger:
        image:
          repository: "709825985650.dkr.ecr.us-east-1.amazonaws.com/scalar/scalar-ledger"
          version: "3.6.0"
        imagePullSecrets:
          - name: "reg-ecr-mp-secrets"
        ledgerProperties: |
          scalar.db.contact_points=jdbc:postgresql://postgresql-ledger.default.svc.cluster.local:5432/postgres
          scalar.db.username={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_USERNAME "" }}
          scalar.db.password={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_PASSWORD "" }}
          scalar.db.storage=jdbc
          scalar.dl.ledger.proof.enabled=true
          scalar.dl.ledger.proof.private_key_path=/keys/private-key
        secretName: "ledger-credentials-secret"
        extraVolumes:
          - name: "ledger-keys"
            secret:
              secretName: "ledger-keys"
        extraVolumeMounts:
          - name: "ledger-keys"
            mountPath: "/keys"
            readOnly: true
      EOF
      
    • Azure Marketplace

      cat << 'EOF' > ~/scalardl-test/scalardl-ledger-custom-values.yaml
      envoy:
        image:
          repository: "<your private container registry>/scalarinc/scalardl-envoy"
          version: "1.3.0"
        imagePullSecrets:
          - name: "reg-acr-secrets"
           
      ledger:
        image:
          repository: "<your private container registry>/scalarinc/scalar-ledger"
          version: "3.6.0"
        imagePullSecrets:
          - name: "reg-acr-secrets"
        ledgerProperties: |
          scalar.db.contact_points=jdbc:postgresql://postgresql-ledger.default.svc.cluster.local:5432/postgres
          scalar.db.username={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_USERNAME "" }}
          scalar.db.password={{ default .Env.SCALAR_DL_LEDGER_POSTGRES_PASSWORD "" }}
          scalar.db.storage=jdbc
          scalar.dl.ledger.proof.enabled=true
          scalar.dl.ledger.proof.private_key_path=/keys/private-key
        secretName: "ledger-credentials-secret"
        extraVolumes:
          - name: "ledger-keys"
            secret:
              secretName: "ledger-keys"
        extraVolumeMounts:
          - name: "ledger-keys"
            mountPath: "/keys"
            readOnly: true
      EOF
      
  2. Create secret resource ledger-keys.
    kubectl create secret generic ledger-keys --from-file=private-key=./certs/ledger-key.pem
    
  3. Deploy the ScalarDL Ledger.
    helm install scalardl-ledger scalar-labs/scalardl -f ./scalardl-ledger-custom-values.yaml
    
  4. Check if the ScalarDL Ledger pods are deployed.
    kubectl get pod
    

    [Command execution result]

    NAME                                        READY   STATUS      RESTARTS   AGE
    postgresql-ledger-0                         1/1     Running     0          14m
    scalardl-ledger-envoy-547bbf7546-6cn88      1/1     Running     0          52s
    scalardl-ledger-envoy-547bbf7546-rpg5p      1/1     Running     0          52s
    scalardl-ledger-envoy-547bbf7546-x2vlg      1/1     Running     0          52s
    scalardl-ledger-ledger-9bdf7f8bd-29bzm      1/1     Running     0          52s
    scalardl-ledger-ledger-9bdf7f8bd-9fklw      1/1     Running     0          52s
    scalardl-ledger-ledger-9bdf7f8bd-9tw5x      1/1     Running     0          52s
    schema-loader-ledger-schema-loading-46rcr   0/1     Completed   0          3m38s
    

    If the ScalarDL Ledger pods are deployed properly, you can see the STATUS are Running.

  5. Check if the ScalarDL Ledger services are deployed.
    kubectl get svc
    

    [Command execution result]

    NAME                            TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                         AGE
    kubernetes                      ClusterIP   10.96.0.1        <none>        443/TCP                         47d
    postgresql-ledger               ClusterIP   10.109.253.150   <none>        5432/TCP                        15m
    postgresql-ledger-hl            ClusterIP   None             <none>        5432/TCP                        15m
    scalardl-ledger-envoy           ClusterIP   10.106.141.153   <none>        50051/TCP,50052/TCP             83s
    scalardl-ledger-envoy-metrics   ClusterIP   10.108.36.136    <none>        9001/TCP                        83s
    scalardl-ledger-headless        ClusterIP   None             <none>        50051/TCP,50053/TCP,50052/TCP   83s
    scalardl-ledger-metrics         ClusterIP   10.98.4.217      <none>        8080/TCP                        83s
    

    If the ScalarDL Ledger services are deployed properly, you can see private IP addresses in the CLUSTER-IP column. (Note: scalardl-ledger-headless has no CLUSTER-IP.)

Step 7. Start a Client container

We will use certificate files in a Client container. So, we create a secret resource and mount it to a Client container.

  1. Create secret resource client-keys.
    kubectl create secret generic client-keys --from-file=certificate=./certs/client.pem --from-file=private-key=./certs/client-key.pem
    
  2. Start a Client container on the Kubernetes cluster.
    cat << 'EOF' | kubectl apply -f -
    apiVersion: v1
    kind: Pod
    metadata:
      name: "scalardl-client"
    spec:
      containers:
        - name: scalardl-client
          image: eclipse-temurin:8
          command: ['sleep']
          args: ['inf']
          volumeMounts:
            - name: "client-keys"
              mountPath: "/keys"
              readOnly: true
      volumes:
        - name: "client-keys"
          secret:
            secretName: "client-keys"
      restartPolicy: Never 
    EOF
    
  3. Check if the Client container is running.
    kubectl get pod scalardl-client
    

    [Command execution result]

    NAME              READY   STATUS    RESTARTS   AGE
    scalardl-client   1/1     Running   0          11s
    

Step 8. Run ScalarDL sample contracts in the Client container

The following explains the minimum steps. If you want to know more details about ScalarDL and the contract, please refer to the Getting Started with ScalarDL.

  1. Run bash in the Client container.
    kubectl exec -it scalardl-client -- bash
    

    After this step, run each command in the Client container.

  2. Install the git, curl and unzip commands in the Client container.
    apt update && apt install -y git curl unzip
    
  3. Clone ScalarDL Java Client SDK git repository.
    git clone https://github.com/scalar-labs/scalardl-java-client-sdk.git
    
  4. Change the directory to scalardl-java-client-sdk/.
    cd scalardl-java-client-sdk/
    
    pwd
    

    [Command execution result]

    
    /scalardl-java-client-sdk
    
  5. Change branch to arbitrary version.
    git checkout -b v3.6.0 refs/tags/v3.6.0
    
    git branch
    

    [Command execution result] ```console master

    • v3.6.0 ``` If you want to use another version, please specify the version (tag) you want to use. You need to use the same version of ScalarDL Ledger and ScalarDL Java Client SDK.
  6. Build the sample contracts.
    ./gradlew assemble
    
  7. Download CLI tools of ScalarDL from ScalarDL Java Client SDK Releases.
    curl -OL https://github.com/scalar-labs/scalardl-java-client-sdk/releases/download/v3.6.0/scalardl-java-client-sdk-3.6.0.zip
    

    You need to use the same version of CLI tools and ScalarDL Ledger.

  8. Unzip the scalardl-java-client-sdk-3.6.0.zip file.
    unzip ./scalardl-java-client-sdk-3.6.0.zip
    
  9. Create a configuration file (client.properties) to access ScalarDL Ledger on the Kubernetes cluster.
    cat << 'EOF' > client.properties
    scalar.dl.client.server.host=scalardl-ledger-envoy.default.svc.cluster.local
    scalar.dl.client.cert_holder_id=client
    scalar.dl.client.cert_path=/keys/certificate
    scalar.dl.client.private_key_path=/keys/private-key
    EOF
    
  10. Register the certificate file of the client.
    ./scalardl-java-client-sdk-3.6.0/bin/register-cert --properties ./client.properties
    
  11. Register the sample contract StateUpdater.
    ./scalardl-java-client-sdk-3.6.0/bin/register-contract --properties ./client.properties --contract-id StateUpdater --contract-binary-name com.org1.contract.StateUpdater --contract-class-file ./build/classes/java/main/com/org1/contract/StateUpdater.class
    
  12. Register the sample contract StateReader.
    ./scalardl-java-client-sdk-3.6.0/bin/register-contract --properties ./client.properties --contract-id StateReader --contract-binary-name com.org1.contract.StateReader --contract-class-file ./build/classes/java/main/com/org1/contract/StateReader.class
    
  13. Execute the contract StateUpdater.
    ./scalardl-java-client-sdk-3.6.0/bin/execute-contract --properties ./client.properties --contract-id StateUpdater --contract-argument '{"asset_id": "test_asset", "state": 3}'
    

    This sample contract updates the state (value) of the asset named test_asset to 3.

  14. Execute the contract StateReader.
    ./scalardl-java-client-sdk-3.6.0/bin/execute-contract --properties ./client.properties --contract-id StateReader --contract-argument '{"asset_id": "test_asset"}'
    

    [Command execution result]

    Contract result:
    {
      "id" : "test_asset",
      "age" : 0,
      "output" : {
        "state" : 3
      }
    }
    
  15. Execute a validation request for the asset.
    ./scalardl-java-client-sdk-3.6.0/bin/validate-ledger --properties ./client.properties --asset-id "test_asset"
    

    [Command execution result]

    {
      "status_code" : "OK",
      "Ledger" : {
        "id" : "test_asset",
        "age" : 0,
        "nonce" : "f31599c6-e6b9-4b77-adc3-61cb5f119bd3",
        "hash" : "9ExfFl5Lg9IQwdXdW9b87Bi+PWccn3OSNRbhmI/dboo=",
        "signature" : "MEQCIG6Xa4WOWGMIIbA3PnCje4aAapYfCMerF54xRW0gaUuzAiBCA1nCAPoFWgxArB34/u9b+KeoxQBMALI/pOzMNoLExg=="
      },
      "Auditor" : null
    }
    
    • Reference information
      • If the asset data is not tampered with, the validation request (validate-ledger command) returns OK as a result.
      • If the asset data is tampered with (e.g. the state value in the DB is tampered with), the validation request (validate-ledger command) returns a value other than OK (e.g. INVALID_OUTPUT) as a result, like the following.
        [Command execution result (If the asset data is tampered with)]
        {
          "status_code" : "INVALID_OUTPUT",
          "Ledger" : {
            "id" : "test_asset",
            "age" : 0,
            "nonce" : "f31599c6-e6b9-4b77-adc3-61cb5f119bd3",
            "hash" : "9ExfFl5Lg9IQwdXdW9b87Bi+PWccn3OSNRbhmI/dboo=",
            "signature" : "MEQCIGtJerW7N93c/bvIBy/7NXxoQwGFznHMmV6RzsgHQg0dAiBu+eBxkfmMQKJY2d9fLNvCH+4b+9rl7gZ3OXJ2NYeVsA=="
          },
          "Auditor" : null
        }
        
        • In this way, the ScalarDL Ledger can detect data tampering.

Step 9. Delete all resources

After completing the ScalarDL Ledger tests on the Kubernetes cluster, remove all resources.

  1. Uninstall ScalarDL Ledger, ScalarDL Schema Loader, and PostgreSQL.
    helm uninstall scalardl-ledger schema-loader-ledger postgresql-ledger
    
  2. Remove the Client container.
    kubectl delete pod scalardl-client --force --grace-period 0
    
  3. Remove the working directory and sample files (configuration file, key, and certificate).
    cd ~
    
    rm -rf ~/scalardl-test/
    

Further reading

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