135: Deployment of openim on Kubernetes with Configuration Management using Helm

Description: As part of our infrastructure evolution, we are considering deploying our openim application on Kubernetes. Given the application's reliance on specific configurations for MySQL and RPC, we need to devise a strategy that securely and efficiently manages these configurations within a Kubernetes environment.

Proposed Solution:

1. Configuration Split:

   • MySQL Configuration: Given the sensitivity of the MySQL configuration (it contains credentials), this configuration should be stored within a Kubernetes Secret.
   • RPC Configuration: This configuration can be stored within a Kubernetes ConfigMap since it doesn't seem to contain sensitive data.

2. Configuration Deployment with Helm:

   Helm, being the package manager for Kubernetes, will allow us to template and package these configurations for easier deployment and management.

   • Create a Helm chart for openim with the following structure:

     openim/
     ├── charts/
     ├── templates/
     │   ├── configmap.yaml
     │   ├── secret.yaml
     │   ├── deployment.yaml
     │   ├── service.yaml
     │   └── ... (other Kubernetes objects)
     ├── values.yaml
     └── Chart.yaml
     

   • In the values.yaml file, provide default values (or placeholders) for all configurations.

   • In templates/configmap.yaml and templates/secret.yaml, template the configurations to take values from values.yaml.

   • Users can then override the default configurations during Helm deployment using their custom values.

3. Mounting Configurations in the Application:

   • Mount the MySQL configuration stored in the Secret as environment variables within the application container.
   • Mount the RPC configuration from the ConfigMap as a file within the application container, and ensure the openim application reads configurations from this file path.

4. Helm Deployment: Once the Helm chart is created, the application can be deployed using:

   helm install openim ./openim --values custom-values.yaml
   

Tasks:

• Split the configurations as per the defined structure.
• Set up the basic structure of the Helm chart for openim.
• Template the configurations within the Helm chart.
• Modify the openim application to read configurations from the specified paths.
• Test the deployment on a development Kubernetes cluster.
• Document the deployment process.

Benefits:

• Improved configuration management.
• Enhanced security for sensitive configurations.
• Scalable deployment solution using Helm.
• Easier application upgrades and rollbacks with Helm.