test-helm-charts

Test repository for Webrix Helm charts used for development and testing before production release.

Overview

This repository contains multiple Helm charts for the MCP-S (Multi-Cloud Platform Service) stack. The main chart (mcp-s) serves as an umbrella chart that includes all other service charts as dependencies.

Chart Structure

• mcp-s - Master/umbrella chart that orchestrates all services
• mcp-s-app - Application service
• mcp-s-connect - Connection service
• mcp-s-run - Runtime service
• mcp-s-db-service - Database service
• mcp-s-grafana - Monitoring with Grafana

Local Development

Prerequisites

• Helm 3.x installed
• Access to the Webrix container registry (if pulling images)

Setting Up for Local Testing

When testing locally without a Helm repository, you need to build dependencies first:

cd charts/mcp-s
helm dependency build .

This command downloads all dependent charts specified in Chart.yaml and places them in the charts/ directory.

Configuration and Overrides

Helm provides multiple ways to override default values:

1. Using --set flags (inline overrides)
2. Using values files with -f values.yaml
3. Combining both methods

Override Examples

Testing App Service Configuration

helm template . --set app.replicas=1000 --set app.appVersion=ttttttt -f values.yaml --debug | grep -E "(image|replicas)" -B 3 -A 3

Testing Connect Service Configuration

helm template . --set connect.replicas=1000 --set connect.appVersion=ttttttt -f values.yaml --debug | grep -E "(image|replicas)" -B 3 -A 3

Testing Run Service Configuration

helm template . --set run.replicas=1000 --set run.appVersion=ttttttt -f values.yaml --debug | grep -E "(image|replicas)" -B 3 -A 3

Testing DB Service Configuration

helm template . --set dbservice.replicas=1000 --set dbservice.appVersion=ttttttt -f values.yaml --debug | grep -E "(image|replicas)" -B 3 -A 3

Note: The db-service chart uses an alias dbservice in the dependencies because Helm doesn't support hyphens in subchart value keys. This is defined in the Chart.yaml dependencies section.

Understanding the Output

The grep command with -B 3 -A 3 shows 3 lines before and after matches, helping you verify:

• Image tags are correctly set
• Replica counts are properly configured
• The context around these settings

Testing Workflow

1. Make changes to your values or chart templates
2. Build dependencies if you've modified dependency versions
3. Template the chart to see the generated Kubernetes manifests
4. Validate the output matches your expectations
5. Deploy to a test cluster when ready

Values File Structure

The values.yaml file in the mcp-s chart can override values for all subcharts:

# Override for app service
app:
  replicas: 3
  appVersion: "v1.2.3"

# Override for connect service  
connect:
  replicas: 2
  appVersion: "v1.2.3"

# Override for db-service (using alias)
dbservice:
  replicas: 1
  appVersion: "v1.2.3"

Dynamic Environment Variables

All dependency charts support dynamic environment variables. This allows you to inject custom environment variables into any service container at runtime without modifying the chart templates.

How It Works

Any environment variable set under the .env key of a dependency chart will be automatically injected into the target container's environment variables.

Syntax

--set <service>.env.<ENV_VAR_NAME>=<value>

Examples

Setting Environment Variables for Connect Service

helm template . --set connect.env.THIS_IS_TEST=1 --set connect.env.DEBUG_MODE=true -f values.yaml

Setting Environment Variables for App Service

helm template . --set app.env.LOG_LEVEL=debug --set app.env.FEATURE_FLAG=enabled -f values.yaml

Setting Environment Variables for DB Service

helm template . --set dbservice.env.DB_POOL_SIZE=20 --set dbservice.env.TIMEOUT=30s -f values.yaml

Testing Dynamic Environment Variables

To verify that environment variables are correctly set, use grep to filter the templated output:

# Test connect service environment variables
helm template . --set connect.env.THIS_IS_TEST=1 --set connect.env.DEBUG_MODE=true -f values.yaml --debug | grep -E "(THIS_IS_TEST|DEBUG_MODE)" -B 2 -A 2

# Test multiple services with environment variables
helm template . --set app.env.LOG_LEVEL=debug --set connect.env.API_TIMEOUT=60s -f values.yaml --debug | grep -E "(LOG_LEVEL|API_TIMEOUT)" -B 2 -A 2

Using Values Files for Environment Variables

You can also define environment variables in your values.yaml:

connect:
  env:
    THIS_IS_TEST: "1"
    DEBUG_MODE: "true"
    API_ENDPOINT: "https://api.example.com"

app:
  env:
    LOG_LEVEL: "debug"
    CACHE_TTL: "3600"

dbservice:
  env:
    DB_POOL_SIZE: "20"
    CONNECTION_TIMEOUT: "30s"

Deployment

For actual deployment to a Kubernetes cluster:

helm install mcp-s ./charts/mcp-s -f values.yaml --namespace your-namespace

Or for upgrades:

helm upgrade mcp-s ./charts/mcp-s -f values.yaml --namespace your-namespace

Troubleshooting

• If dependency build fails, check your Chart.yaml for correct chart names and versions
• Use helm template with --debug flag to see detailed output
• For subchart overrides not working, verify the alias names in the dependencies
• Check that your values path matches the dependency alias (e.g., dbservice.replicas not db-service.replicas)