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Kubernetes and Container Orchestration

Benefits of Kubernetes​

Using Kubernetes offers numerous advantages for deploying and managing the OPC Router:

  • Scalability: Kubernetes allows you to scale the number of OPC Router instances based on current requirements.
  • **Flexibility: By using containers, different versions and configurations of the OPC Router can be easily managed and deployed.
  • Automation: Kubernetes automates many administrative tasks, including deployments, rollbacks, and scaling, which simplifies management and reduces errors.

Helm Chart for OPC Router​

The Helm chart for the OPC Router simplifies the deployment and management of the OPC Router in a Kubernetes cluster. Here are the main features and configuration options:

Deployment:​

  • Helm Chart: Enables deployment of the OPC Router on any Kubernetes cluster.
  • Multiple Configurations: Support for various configuration options to meet specific requirements.

configuration:​

  • Global Parameters: Settings such as the global Docker image registry and StorageClass.
  • Common Parameters: Parameters for customizing the name and service account settings.
  • **OPC Router Parameters: Configurations for the OPC Router image, environment variables, and project repository.
  • MongoDB Parameters: Settings for MongoDB integration, including authentication and redundancy.

Redundancy:​

  • OPC Router Redundancy: Support for redundancy mode to run a second pod with an OPC Router runtime that takes over in the event of a failure of the primary pod.
  • **MongoDB Redundancy: Ability to run multiple MongoDB pods to provide database redundancy and increase reliability.

Best Practices​

To take full advantage of Kubernetes and Helm Charts, the following best practices should be followed:

Private Repositories:​

  • Ensure that Git repositories are private to prevent unauthorized access.
  • Establishing a connection between the OPC Router’s internal Git system and hosted Git servers such as GitHub, Bitbucket, or Microsoft Azure DevOps.

Secrets Management:​

  • Secrets and passwords should never be stored in a Git repository.
  • The OPC Router always stores secrets in a separate local vault to ensure they are not versioned.

Regular Updates and Monitoring:​

  • Regularly updating the Kubernetes cluster and Helm charts.
  • Monitoring the cluster to ensure that all components are functioning and scaling properly.

Practical Implementation​

Deployment with Helm Chart:​

  1. Prerequisites: Ensure that Kubernetes and Helm are installed and configured

  2. Add the Helm Repository: Add the OPC Router Helm repository and update it:

    helm repo add opc-router https://opc-router.github.io/helm-charts
    helm repo update

  3. Installing the OPC Router: Use the following command to install the OPC Router:

    helm install my-opcrouter opc-router/opc-router --set I_do_accept_the_EULA=true

  4. Security Configuration: Add authentication and security parameters to secure the installation. Write the values to a values.yaml file instead of passing them individually via --set:

    values.yaml
    webManagement:
      auth:
        disable: false
        initialUser:
          name: <initial-web-management-user>
          password: <initial-web-management-password>
    mongodb:
      auth:
        enabled: true
        rootPassword: <mongodb-root-password>
        replicaSetKey: <mongodb-replicaset-key>
    I_do_accept_the_EULA: true
    helm install my-opcrouter opc-router/opc-router -f values.yaml
    warning

    Do not pass passwords via --set on the command line: The command ends up in the shell history and is visible in the process list on the machine. A values.yaml should not be stored in version control in plain text—for production environments, refer to an existing Kubernetes secret or pass individual values via --set-file from a file with restricted access rights.

Redundancy and Scaling:​

  1. Enable OPC Router Redundancy: The redundancy mode is set via the OPC Router’s environment variables, which you pass to the pod—primarily OR_REDUNDANCY_MODE (primary or secondary), OR_REDUNDANCY_SHARED_KEY, and, on the secondary service, OR_REDUNDANCY_ADDRESS. The complete list and the meaning of the values can be found under Safe Redundancy and Configurable Environment Variables.

  2. MongoDB Redundancy: Ensure that MongoDB is running in redundancy mode by increasing the number of pods:

    --set mongodb.replicaCount=3
    note

    Use an odd number of at least three pods. A replica set makes decisions by majority vote: With two pods, the remaining node loses quorum after the other fails and enters a read-only state—redundancy does not work in this case. Only with three or more pods can the set withstand the failure of a single node.

Load the project from the Git repository:​

  • Reference the project repository and the path in the Helm chart to load an OPC Router project from a Git repository:

    --set project.projectRepo=<git-repository-url> \
    --set project.projectPath=<path-to-rpe-project-file> \
    --set project.configPath=<path-to-project-config-file> \
    --set project.auth.ssh_key=<private-ssh-key>

Summary​

Using Kubernetes and Helm Charts provides a powerful and flexible way to run the OPC Router in a scalable and manageable environment. By implementing best practices and taking advantage of the configuration options, organizations can maximize the reliability and efficiency of their OPC Router installations.