sal/examples/kubernetes/pattern_deletion.rhai

//! Kubernetes pattern-based deletion example
//!
//! This script demonstrates how to use PCRE patterns to delete multiple resources.
//! 
//! ⚠️  WARNING: This example includes actual deletion operations!
//! ⚠️  Only run this in a test environment!
//! 
//! Prerequisites:
//! - A running Kubernetes cluster (preferably a test cluster)
//! - Valid kubeconfig file or in-cluster configuration
//! - Permissions to delete resources
//!
//! Usage:
//!   herodo examples/kubernetes/pattern_deletion.rhai

print("=== SAL Kubernetes Pattern Deletion Example ===");
print("⚠️  WARNING: This example will delete resources matching patterns!");
print("⚠️  Only run this in a test environment!");

// Create a KubernetesManager for a test namespace
let test_namespace = "sal-pattern-test";
let km = kubernetes_manager_new("default");

print("\nCreating test namespace: " + test_namespace);
try {
    namespace_create(km, test_namespace);
    print("✓ Test namespace created");
} catch(e) {
    print("Note: " + e);
}

// Switch to the test namespace
let test_km = kubernetes_manager_new(test_namespace);
print("Switched to namespace: " + namespace(test_km));

// Show current resources before any operations
print("\n--- Current Resources in Test Namespace ---");
let counts = resource_counts(test_km);
print("Resource counts before operations:");
for resource_type in counts.keys() {
    print("  " + resource_type + ": " + counts[resource_type]);
}

// List current pods to see what we're working with
let current_pods = pods_list(test_km);
print("\nCurrent pods in namespace:");
if current_pods.len() == 0 {
    print("  (no pods found)");
} else {
    for pod in current_pods {
        print("  - " + pod);
    }
}

// Demonstrate pattern matching without deletion first
print("\n--- Pattern Matching Demo (Dry Run) ---");
let test_patterns = [
    "test-.*",           // Match anything starting with "test-"
    ".*-temp$",          // Match anything ending with "-temp"
    "demo-pod-.*",       // Match demo pods
    "nginx-.*",          // Match nginx pods
    "app-[0-9]+",        // Match app-1, app-2, etc.
];

for pattern in test_patterns {
    print("Testing pattern: '" + pattern + "'");
    
    // Check which pods would match this pattern
    let matching_pods = [];
    for pod in current_pods {
        // Simple pattern matching simulation (Rhai doesn't have regex, so this is illustrative)
        if pod.contains("test") && pattern == "test-.*" {
            matching_pods.push(pod);
        } else if pod.contains("temp") && pattern == ".*-temp$" {
            matching_pods.push(pod);
        } else if pod.contains("demo") && pattern == "demo-pod-.*" {
            matching_pods.push(pod);
        } else if pod.contains("nginx") && pattern == "nginx-.*" {
            matching_pods.push(pod);
        }
    }
    
    print("  Would match " + matching_pods.len() + " pods: " + matching_pods);
}

// Example of safe deletion patterns
print("\n--- Safe Deletion Examples ---");
print("These patterns are designed to be safe for testing:");

let safe_patterns = [
    "test-example-.*",      // Very specific test resources
    "sal-demo-.*",          // SAL demo resources
    "temp-resource-.*",     // Temporary resources
];

for pattern in safe_patterns {
    print("\nTesting safe pattern: '" + pattern + "'");
    
    try {
        // This will actually attempt deletion, but should be safe in a test environment
        let deleted_count = delete(test_km, pattern);
        print("✓ Pattern '" + pattern + "' matched and deleted " + deleted_count + " resources");
    } catch(e) {
        print("Note: Pattern '" + pattern + "' - " + e);
    }
}

// Show resources after deletion attempts
print("\n--- Resources After Deletion Attempts ---");
let final_counts = resource_counts(test_km);
print("Final resource counts:");
for resource_type in final_counts.keys() {
    print("  " + resource_type + ": " + final_counts[resource_type]);
}

// Example of individual resource deletion
print("\n--- Individual Resource Deletion Examples ---");
print("These functions delete specific resources by name:");

// These are examples - they will fail if the resources don't exist, which is expected
let example_deletions = [
    ["pod", "test-pod-example"],
    ["service", "test-service-example"],
    ["deployment", "test-deployment-example"],
];

for deletion in example_deletions {
    let resource_type = deletion[0];
    let resource_name = deletion[1];
    
    print("Attempting to delete " + resource_type + ": " + resource_name);
    try {
        if resource_type == "pod" {
            pod_delete(test_km, resource_name);
        } else if resource_type == "service" {
            service_delete(test_km, resource_name);
        } else if resource_type == "deployment" {
            deployment_delete(test_km, resource_name);
        }
        print("✓ Successfully deleted " + resource_type + ": " + resource_name);
    } catch(e) {
        print("Note: " + resource_type + " '" + resource_name + "' - " + e);
    }
}

print("\n--- Best Practices for Pattern Deletion ---");
print("1. Always test patterns in a safe environment first");
print("2. Use specific patterns rather than broad ones");
print("3. Consider using dry-run approaches when possible");
print("4. Have backups or be able to recreate resources");
print("5. Use descriptive naming conventions for easier pattern matching");

print("\n--- Cleanup ---");
print("To clean up the test namespace:");
print("  kubectl delete namespace " + test_namespace);

print("\n=== Pattern deletion example completed! ===");