docker-compose.infra.yml

# docker-compose.infra.yml
# Phase 1: Infrastructure Foundation — Redis + Kafka (KRaft mode, no ZooKeeper)
#
# Usage:
#   docker compose -f docker-compose.infra.yml up -d
#   docker compose -f docker-compose.infra.yml down -v   # tear down with volumes
#
# Version Matrix (as of Feb 2026):
#   - Redis: 7.4.x (latest stable)
#   - Kafka: apache/kafka:latest (official Apache image, KRaft mode)
#   - Kafka UI: latest (optional, for visual inspection)
#
# NOTE: Bitnami Kafka images are no longer freely available on Docker Hub
#       (moved behind Broadcom paywall Sep 2025). We use the official
#       Apache Kafka image instead.

name: apollo-subs-infra

networks:
  apollo-subs-net:
    driver: bridge

volumes:
  redis-data:
  kafka-data:

services:
  # ──────────────────────────────────────────────────────────
  # Redis 7.4 — Subscription state store (callback URLs, TTLs, verifiers)
  # ──────────────────────────────────────────────────────────
  redis:
    image: redis:7.4-alpine
    container_name: redis
    hostname: redis
    ports:
      - "6379:6379"
    volumes:
      - redis-data:/data
    networks:
      - apollo-subs-net
    command: >
      redis-server
      --appendonly yes
      --maxmemory 256mb
      --maxmemory-policy allkeys-lru
      --save 60 1000
      --loglevel notice
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: 5s
      timeout: 3s
      retries: 5
      start_period: 5s
    restart: unless-stopped

  # ──────────────────────────────────────────────────────────
  # Kafka (Official Apache image) — KRaft combined mode
  # Image: apache/kafka (available since Kafka 3.7+, currently 4.1.x)
  # No ZooKeeper needed — uses built-in KRaft consensus
  #
  # Env var convention: KAFKA_ prefix + config name with dots→underscores
  #   e.g. num.partitions → KAFKA_NUM_PARTITIONS
  # ──────────────────────────────────────────────────────────
  kafka:
    image: apache/kafka:latest
    container_name: kafka
    hostname: kafka
    ports:
      - "9092:9092"       # External (host) listener
    volumes:
      - kafka-data:/tmp/kraft-combined-logs
    networks:
      - apollo-subs-net
    environment:
      # ── KRaft Combined Mode (broker + controller in one process) ──
      KAFKA_NODE_ID: 1
      KAFKA_PROCESS_ROLES: broker,controller
      KAFKA_CONTROLLER_QUORUM_VOTERS: 1@kafka:9093
      KAFKA_CONTROLLER_LISTENER_NAMES: CONTROLLER

      # ── Listener Configuration ──
      # INTERNAL  → Docker-internal communication (subgraphs, other containers)
      # EXTERNAL  → Host machine access (for local dev tooling, kafka-init)
      # CONTROLLER → KRaft consensus (internal only)
      KAFKA_LISTENERS: INTERNAL://:19092,EXTERNAL://:9092,CONTROLLER://:9093
      KAFKA_ADVERTISED_LISTENERS: INTERNAL://kafka:19092,EXTERNAL://localhost:9092
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: INTERNAL:PLAINTEXT,EXTERNAL:PLAINTEXT,CONTROLLER:PLAINTEXT
      KAFKA_INTER_BROKER_LISTENER_NAME: INTERNAL

      # ── Cluster ID (required for KRaft) ──
      CLUSTER_ID: apollo-subs-kafka-cluster-01

      # ── Topic Defaults ──
      KAFKA_AUTO_CREATE_TOPICS_ENABLE: "false"
      KAFKA_NUM_PARTITIONS: 3
      KAFKA_DEFAULT_REPLICATION_FACTOR: 1
      KAFKA_MIN_INSYNC_REPLICAS: 1
      KAFKA_LOG_RETENTION_HOURS: 24

      # ── Performance Tuning ──
      KAFKA_MESSAGE_MAX_BYTES: 1048576
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
    healthcheck:
      test: >
        /opt/kafka/bin/kafka-topics.sh --bootstrap-server localhost:9092 --list || exit 1
      interval: 10s
      timeout: 5s
      retries: 10
      start_period: 30s
    restart: unless-stopped

  # ──────────────────────────────────────────────────────────
  # Kafka Topic Initializer — Creates required topics on startup
  # Runs once and exits after topics are created
  # ──────────────────────────────────────────────────────────
  kafka-init:
    image: apache/kafka:latest
    container_name: kafka-init
    networks:
      - apollo-subs-net
    depends_on:
      kafka:
        condition: service_healthy
    entrypoint: ["/bin/bash", "-c"]
    command:
      - |
        echo "🚀 Creating Kafka topics..."

        # notification-events: Main subscription event topic
        # 3 partitions to support 2+ subgraph consumer instances
        /opt/kafka/bin/kafka-topics.sh --create \
          --if-not-exists \
          --bootstrap-server kafka:19092 \
          --topic notification-events \
          --partitions 3 \
          --replication-factor 1 \
          --config retention.ms=86400000 \
          --config cleanup.policy=delete

        # system-alerts: Broadcast topic for system-wide alerts
        # Single partition — all consumers receive all messages
        /opt/kafka/bin/kafka-topics.sh --create \
          --if-not-exists \
          --bootstrap-server kafka:19092 \
          --topic system-alerts \
          --partitions 1 \
          --replication-factor 1 \
          --config retention.ms=86400000 \
          --config cleanup.policy=delete

        # order-status-changed: Consumed by the Orders subgraph (Redis-backed architecture).
        # Partitioned by orderId key — same order always hits the same partition.
        # Multiple subgraph pods in the same consumer group share partitions automatically.
        /opt/kafka/bin/kafka-topics.sh --create \
          --if-not-exists \
          --bootstrap-server kafka:19092 \
          --topic order-status-changed \
          --partitions 3 \
          --replication-factor 1 \
          --config retention.ms=86400000 \
          --config cleanup.policy=delete

        echo ""
        echo "✅ Topics created successfully:"
        /opt/kafka/bin/kafka-topics.sh --list --bootstrap-server kafka:19092

        echo ""
        echo "📊 Topic details:"
        /opt/kafka/bin/kafka-topics.sh --describe --bootstrap-server kafka:19092 --topic notification-events
        /opt/kafka/bin/kafka-topics.sh --describe --bootstrap-server kafka:19092 --topic system-alerts
        /opt/kafka/bin/kafka-topics.sh --describe --bootstrap-server kafka:19092 --topic order-status-changed

  # ──────────────────────────────────────────────────────────
  # Kafka UI — Optional visual inspection tool
  # Access at http://localhost:8080
  # ──────────────────────────────────────────────────────────
  kafka-ui:
    image: provectuslabs/kafka-ui:latest
    container_name: kafka-ui
    ports:
      - "8080:8080"
    networks:
      - apollo-subs-net
    depends_on:
      kafka:
        condition: service_healthy
    environment:
      - KAFKA_CLUSTERS_0_NAME=apollo-subs-local
      - KAFKA_CLUSTERS_0_BOOTSTRAPSERVERS=kafka:19092
      - DYNAMIC_CONFIG_ENABLED=true
    restart: unless-stopped