# Drone CI Jsonnet Configuration Guide

## ✅ **Jsonnet is Now Enabled!**

Your Drone CI server now supports Jsonnet configurations with the following setup:

### 🔧 **Server Configuration**

The following environment variables have been added to enable Jsonnet:

```yaml
DRONE_JSONNET_ENABLED: "true"
DRONE_STARLARK_ENABLED: "true"  # Bonus: Starlark support too
```

### 📁 **File Structure**

```
├── .drone.jsonnet           # Main pipeline configuration
├── common.libsonnet         # Shared steps and environment
├── build-steps.libsonnet    # Build-specific logic
├── .drone.yml.backup        # Original YAML (backup)
└── drone-configmap-updated.yaml  # Updated server config
```

## 🚀 **How to Use Jsonnet**

### **1. Main Configuration (`.drone.jsonnet`)**
- Entry point for your pipeline
- Imports and combines modules
- Generates final pipeline configuration

### **2. Common Module (`common.libsonnet`)**
- Shared environment variables
- Common steps (clone, test, cleanup)
- Reusable triggers and conditions

### **3. Build Module (`build-steps.libsonnet`)**
- Build-specific logic
- External Buildah integration
- Container build steps

## 🔄 **Workflow**

1. **Edit Jsonnet files** (`.drone.jsonnet`, `*.libsonnet`)
2. **Test locally** (optional): `jsonnet .drone.jsonnet`
3. **Commit and push** - Drone automatically processes Jsonnet
4. **Pipeline runs** using generated configuration

## 🛠️ **Local Development**

### **Generate YAML for testing:**
```bash
# Generate YAML from Jsonnet
jsonnet .drone.jsonnet > .drone.yml.test

# Validate generated YAML
python3 -c "import yaml; yaml.safe_load(open('.drone.yml.test'))"

# Compare with original
diff .drone.yml.backup .drone.yml.test
```

### **Jsonnet Utilities:**
```bash
# Format Jsonnet files
jsonnetfmt -i .drone.jsonnet common.libsonnet build-steps.libsonnet

# Validate syntax
jsonnet .drone.jsonnet > /dev/null && echo "✅ Valid Jsonnet"
```

## 🎯 **Benefits Achieved**

### **Modularity**
- ✅ Separate concerns (common vs build-specific)
- ✅ Reusable components
- ✅ Easier maintenance

### **Flexibility**
- ✅ Variables and functions
- ✅ Conditional logic
- ✅ Dynamic configuration

### **DRY Principle**
- ✅ No code duplication
- ✅ Single source of truth
- ✅ Consistent patterns

## 📋 **Configuration Examples**

### **Creating Environment-Specific Builds:**

```jsonnet
// .drone.jsonnet
local buildSteps = import 'build-steps.libsonnet';
local commonConfig = import 'common.libsonnet';

local environment = std.extVar('environment');

{
  kind: "pipeline",
  type: "kubernetes",
  name: "auth-service-" + environment,
  service_account: "drone-runner",
  environment: commonConfig.environment + {
    BUILD_ENV: environment
  },
  steps: [
    commonConfig.cloneStep,
    commonConfig.testStep,
    buildSteps.externalBuildahStep + {
      commands: [
        // Add environment-specific commands
        "echo 'Building for: " + environment + "'",
      ] + buildSteps.externalBuildahStep.commands
    }
  ]
}
```

### **Adding Conditional Steps:**

```jsonnet
// build-steps.libsonnet
{
  externalBuildahStep: {
    // ... existing configuration
    commands: [
      // ... existing commands
    ] + (
      if std.extVar('push_to_registry') == 'true' then [
        "echo '📤 Pushing to registry...'",
        "kubectl exec $BUILDAH_POD -- buildah push auth-service:1.0.${DRONE_BUILD_NUMBER} docker://registry.aipice.local/auth-service:1.0.${DRONE_BUILD_NUMBER}"
      ] else []
    )
  }
}
```

## 🔍 **Troubleshooting**

### **Check if Jsonnet is enabled:**
```bash
kubectl get configmap drone -n apps--droneio--prd -o yaml | grep JSONNET
```

### **Verify Drone server restart:**
```bash
kubectl get pods -n apps--droneio--prd | grep droneio
```

### **Test Jsonnet syntax:**
```bash
jsonnet .drone.jsonnet | python3 -c "import sys,yaml; yaml.safe_load(sys.stdin)"
```

### **View generated pipeline in Drone UI:**
- Go to your repository in Drone UI
- The generated YAML will be shown in the build view

## 🎉 **Next Steps**

1. **Create variants**: Development, staging, production configurations
2. **Add functions**: Custom build logic, notification steps
3. **Share modules**: Reuse across multiple repositories
4. **Optimize**: Use Jsonnet's advanced features for complex scenarios

Your Drone CI is now supercharged with Jsonnet! 🚀