CSL Examples - Real World Schemas

Docker Compose Schema

Common Docker Compose Structure

services:
  web:
    image: nginx:latest
    ports:
      - "80:80"
    environment:
      - NODE_ENV=production
    volumes:
      - ./app:/app

CSL Implementation

config DockerCompose {
  services: {
    *: { // Wildcard service names
      image?: string @regex(".+:.+");
      build?: {
        context: string;
        dockerfile?: string;
      };
      ports?: string[] @regex("^\\d+:\\d+$");
      environment?: { 
        *: string | number | boolean;
      };
      volumes?: string[];
      networks?: string[];
      
      constraints {
        conflicts build with image;
        validate exists(ports) ? environment.NODE_ENV != "test" : true;
      }
    };
  };
  
  volumes?: {
    *: {}; // Anonymous volumes
  };
  
  networks?: {
    *: { // Network definitions
      driver?: "bridge" | "overlay";
      external?: boolean;
    };
  };
}

Key CSL Features Used

Wildcard service names (*:)
Type unions for environment values
Conflict constraints between build/image
Regex validation for image tags and ports

GitHub Actions Workflow

Typical GitHub Actions File

name: CI
on: [push, pull_request]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Run tests
        run: npm test

CSL Schema

config GitHubActions {
  name: string;
  on: string | string[] | {
    push?: { branches?: string[] };
    pull_request?: { paths?: string[] };
  };
  
  env?: {
    *: string | number;
  };
  
  jobs: {
    *: { // Job names
      runs-on: "ubuntu-latest" | "macos-latest" | "windows-latest";
      needs?: string[];
      steps: {
        name?: string;
        uses?: string @regex("^actions/");
        run?: string;
        with?: { 
          *: string | number | boolean;
        };
        
        constraints {
          validate exists(uses) || exists(run);
          conflicts uses with run;
          validate uses ? with : true;
        }
      }[];
    };
  };
}

Key Validation Rules

Mutually exclusive uses and run
Action path validation for trusted sources
Environment variable type safety
Supported runner OS constraints

AWS CloudFormation Template

Sample Resource

Resources:
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: my-app-bucket
      AccessControl: Private
      CorsConfiguration:
        CorsRules:
          - AllowedOrigins: ["*"]

CSL Schema

config CloudFormation {
  Resources: {
    *: { // Resource names
      Type: string @start_with("AWS::");
      Properties: any{}; // Flexible properties
      DependsOn?: string | string[];
      Metadata?: any{};
      
      constraints {
        validate Type == "AWS::S3::Bucket" ? 
          Properties.BucketName @regex("^[a-z0-9-]+$") : 
          true;
      }
    };
  };
  
  Parameters?: {
    *: {
      Type: "String" | "Number" | "List";
      Default?: string | number;
      AllowedValues?: any[];
    };
  };
  
  Outputs?: {
    *: {
      Value: string;
      Export?: { Name: string };
    };
  };
}

Notable Implementations

Dynamic resource type validation
Complex regex constraints for specific resources
Flexible any{} for AWS property complexity
Parameter type safety

Config Schema Language

Real-world Examples

Docker Compose Schema

Common Docker Compose Structure

CSL Implementation

Key CSL Features Used

GitHub Actions Workflow

Typical GitHub Actions File

CSL Schema

Key Validation Rules

AWS CloudFormation Template

Sample Resource

CSL Schema

Notable Implementations

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