prvng_kcl/examples/kubernetes_deployment.k

# Kubernetes Deployment Example
# Shows complete K8s deployment with services, volumes, and monitoring

import ..main

# Web application deployment in Kubernetes
webapp_k8s: main.K8sDeploy = main.K8sDeploy {
    name: "webapp"
    namespace: "production"
    create_ns: True

    # Deployment specification
    spec: main.K8sDeploySpec {
        replicas: 3
        containers: [
            main.K8sContainers {
                name: "webapp"
                image: "nginx:1.21-alpine"

                # Port configuration
                ports: [
                    main.K8sPort {
                        name: "http"
                        container: 80
                        target: 8080
                    }
                ]

                # Resource requirements
                resources_requests: main.K8sResources {
                    memory: "64Mi"
                    cpu: "50m"
                }
                resources_limits: main.K8sResources {
                    memory: "128Mi"
                    cpu: "100m"
                }

                # Environment variables
                env: [
                    main.K8sKeyVal {
                        key: "NODE_ENV"
                        value: "production"
                    },
                    main.K8sKeyVal {
                        key: "LOG_LEVEL"
                        value: "info"
                    }
                ]

                # Mount configuration volume
                volumeMounts: [
                    main.K8sVolumeMount {
                        name: "config"
                        mountPath: "/etc/nginx/conf.d"
                        readOnly: True
                    }
                ]
            }
        ]

        # Volume configuration
        volumes: [
            main.K8sVolume {
                name: "config"
                typ: "configMap"
                configMap: main.K8sConfigMap {
                    name: "webapp-config"
                }
            }
        ]

        # Node selection for production workloads
        nodeSelector: [
            main.K8sKeyVal {
                key: "node-type"
                value: "production"
            }
        ]

        # Anti-affinity to spread pods across nodes
        affinity: main.K8sAffinity {
            antiAffinity: main.K8sAntyAffinityLabelSelector {
                typ: "preferredDuringSchedulingIgnoredDuringExecution"
                weight: 100
                labelSelector: [
                    main.K8sAffinityMatch {
                        key: "app"
                        operator: "In"
                        values: ["webapp"]
                    }
                ]
                topologyKey: "kubernetes.io/hostname"
            }
        }
    }

    # Service configuration
    service: main.K8sService {
        name: "webapp-service"
        typ: "ClusterIP"
        ports: [
            main.K8sPort {
                name: "http"
                target: 80
                nodePort: 30080
            }
        ]
        selector: [
            main.K8sKeyVal {
                key: "app"
                value: "webapp"
            }
        ]
    }

    # Labels for the deployment
    labels: [
        main.K8sKeyVal {
            key: "app"
            value: "webapp"
        },
        main.K8sKeyVal {
            key: "version"
            value: "v1.0.0"
        },
        main.K8sKeyVal {
            key: "environment"
            value: "production"
        }
    ]
}

# Database deployment with persistent storage
database_k8s: main.K8sDeploy = main.K8sDeploy {
    name: "postgres"
    namespace: "production"

    spec: main.K8sDeploySpec {
        replicas: 1  # Database typically runs single instance
        containers: [
            main.K8sContainers {
                name: "postgres"
                image: "postgres:15-alpine"

                ports: [
                    main.K8sPort {
                        name: "postgres"
                        container: 5432
                        target: 5432
                    }
                ]

                # Database needs more resources
                resources_requests: main.K8sResources {
                    memory: "256Mi"
                    cpu: "100m"
                }
                resources_limits: main.K8sResources {
                    memory: "512Mi"
                    cpu: "500m"
                }

                # Database environment
                env: [
                    main.K8sKeyVal {
                        key: "POSTGRES_DB"
                        value: "webapp"
                    },
                    main.K8sKeyVal {
                        key: "POSTGRES_USER"
                        value: "webapp"
                    },
                    main.K8sKeyVal {
                        key: "POSTGRES_PASSWORD"
                        value: "changeme"  # Use secrets in production
                    }
                ]

                # Persistent data volume
                volumeMounts: [
                    main.K8sVolumeMount {
                        name: "postgres-data"
                        mountPath: "/var/lib/postgresql/data"
                        readOnly: False
                    }
                ]
            }
        ]

        # Persistent volume for database
        volumes: [
            main.K8sVolume {
                name: "postgres-data"
                typ: "volumeClaim"
                persitentVolumeClaim: main.K8sVolumeClaim {
                    name: "postgres-pvc"
                    storageClassName: "manual"
                    storage: "10Gi"
                    modes: ["ReadWriteOnce"]
                    reclaimPolicy: "Retain"
                }
            }
        ]
    }

    # Internal service for database
    service: main.K8sService {
        name: "postgres-service"
        typ: "ClusterIP"
        ports: [
            main.K8sPort {
                name: "postgres"
                target: 5432
            }
        ]
        selector: [
            main.K8sKeyVal {
                key: "app"
                value: "postgres"
            }
        ]
    }

    labels: [
        main.K8sKeyVal {
            key: "app"
            value: "postgres"
        },
        main.K8sKeyVal {
            key: "component"
            value: "database"
        }
    ]
}

# Monitoring deployment using Prometheus
monitoring_k8s: main.K8sDeploy = main.K8sDeploy {
    name: "prometheus"
    namespace: "monitoring"
    create_ns: True

    spec: main.K8sDeploySpec {
        replicas: 1
        containers: [
            main.K8sContainers {
                name: "prometheus"
                image: "prom/prometheus:v2.40.0"

                ports: [
                    main.K8sPort {
                        name: "web"
                        container: 9090
                        target: 9090
                    }
                ]

                resources_requests: main.K8sResources {
                    memory: "512Mi"
                    cpu: "200m"
                }
                resources_limits: main.K8sResources {
                    memory: "1Gi"
                    cpu: "500m"
                }

                volumeMounts: [
                    main.K8sVolumeMount {
                        name: "prometheus-config"
                        mountPath: "/etc/prometheus"
                        readOnly: True
                    },
                    main.K8sVolumeMount {
                        name: "prometheus-data"
                        mountPath: "/prometheus"
                        readOnly: False
                    }
                ]
            }
        ]

        volumes: [
            main.K8sVolume {
                name: "prometheus-config"
                typ: "configMap"
                configMap: main.K8sConfigMap {
                    name: "prometheus-config"
                }
            },
            main.K8sVolume {
                name: "prometheus-data"
                typ: "volumeClaim"
                persitentVolumeClaim: main.K8sVolumeClaim {
                    name: "prometheus-pvc"
                    storage: "20Gi"
                    storageClassName: "manual"
                    modes: ["ReadWriteOnce"]
                }
            }
        ]
    }

    service: main.K8sService {
        name: "prometheus-service"
        typ: "NodePort"
        ports: [
            main.K8sPort {
                name: "web"
                target: 9090
                nodePort: 30090
            }
        ]
    }

    labels: [
        main.K8sKeyVal {
            key: "app"
            value: "prometheus"
        },
        main.K8sKeyVal {
            key: "component"
            value: "monitoring"
        }
    ]
}