# ============================================================================
# DIDI PostgreSQL HA cluster — Patroni + etcd + HAProxy (IaC, reproducible)
#
# Containerized mirror of the production topology (see ../MIGRATION.md):
#   prod: 3× PG/Patroni (10.11.50.160-162) + 3× etcd (163-165)
#         + 2× HAProxy (166/169, VIP 167) + pgBackRest (168)
#   here: 3× Spilo (Patroni+PG, Zalando) + 3× etcd + 1× HAProxy
#         → same failover semantics, single-host footprint for
#           demo/recepție/DR-rehearsal.
#
# Endpoints (identical contract to production):
#   localhost:5000 → leader  (read-write)   [HAProxy checks Patroni /primary]
#   localhost:5001 → replicas (read-only)   [HAProxy checks Patroni /replica]
#   localhost:7000 → HAProxy stats UI
#
# Usage:
#   docker compose up -d
#   # wait ~30s for leader election, then:
#   psql -h localhost -p 5000 -U postgres     # password: $PG_SUPERUSER_PASSWORD
#   # restore DIDI schema:
#   psql -h localhost -p 5000 -U postgres -f ../DIDI_full_export_2026-07-02.sql
#   # failover drill:
#   docker compose stop $(docker compose ps --format '{{.Name}}' | head -1)
#   # → a replica is promoted in seconds; :5000 keeps serving writes.
# ============================================================================

x-etcd-common: &etcd-common
  image: quay.io/coreos/etcd:v3.5.16
  restart: unless-stopped
  networks: [didi-ha]
  environment: &etcd-env
    ETCD_INITIAL_CLUSTER: etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
    ETCD_INITIAL_CLUSTER_STATE: new
    ETCD_INITIAL_CLUSTER_TOKEN: didi-pg-ha
    ETCD_AUTO_COMPACTION_RETENTION: "1"
    ETCD_ENABLE_V2: "true"

x-spilo-common: &spilo-common
  image: ghcr.io/zalando/spilo-16:3.3-p3
  restart: unless-stopped
  networks: [didi-ha]
  environment: &spilo-env
    SCOPE: didi                     # Patroni cluster name (etcd namespace)
    PGVERSION: "16"
    ETCD3_HOSTS: "'etcd1:2379','etcd2:2379','etcd3:2379'"
    PGPASSWORD_SUPERUSER: ${PG_SUPERUSER_PASSWORD:-didi-super-secret}
    PGPASSWORD_ADMIN: ${PG_ADMIN_PASSWORD:-didi-admin-secret}
    PGPASSWORD_STANDBY: ${PG_STANDBY_PASSWORD:-didi-standby-secret}
    ALLOW_NOSSL: "true"
  healthcheck:
    test: ["CMD-SHELL", "curl -sf http://localhost:8008/health || exit 1"]
    interval: 10s
    timeout: 5s
    retries: 6
    start_period: 60s

services:
  etcd1:
    <<: *etcd-common
    container_name: didi-ha-etcd1
    command: etcd --name etcd1
      --listen-peer-urls http://0.0.0.0:2380 --initial-advertise-peer-urls http://etcd1:2380
      --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://etcd1:2379
  etcd2:
    <<: *etcd-common
    container_name: didi-ha-etcd2
    command: etcd --name etcd2
      --listen-peer-urls http://0.0.0.0:2380 --initial-advertise-peer-urls http://etcd2:2380
      --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://etcd2:2379
  etcd3:
    <<: *etcd-common
    container_name: didi-ha-etcd3
    command: etcd --name etcd3
      --listen-peer-urls http://0.0.0.0:2380 --initial-advertise-peer-urls http://etcd3:2380
      --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://etcd3:2379

  pg-node1:
    <<: *spilo-common
    container_name: didi-ha-pg1
    hostname: pg-node1
    depends_on: [etcd1, etcd2, etcd3]
    volumes: [pg1-data:/home/postgres/pgdata]
  pg-node2:
    <<: *spilo-common
    container_name: didi-ha-pg2
    hostname: pg-node2
    depends_on: [etcd1, etcd2, etcd3]
    volumes: [pg2-data:/home/postgres/pgdata]
  pg-node3:
    <<: *spilo-common
    container_name: didi-ha-pg3
    hostname: pg-node3
    depends_on: [etcd1, etcd2, etcd3]
    volumes: [pg3-data:/home/postgres/pgdata]

  haproxy:
    image: haproxy:2.9-alpine
    container_name: didi-ha-haproxy
    restart: unless-stopped
    networks: [didi-ha]
    depends_on: [pg-node1, pg-node2, pg-node3]
    ports:
      - "5000:5000"   # read-write → Patroni leader
      - "5001:5001"   # read-only  → replicas
      - "7000:7000"   # stats UI
    volumes:
      - ./haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro

volumes:
  pg1-data:
  pg2-data:
  pg3-data:

networks:
  didi-ha:
    name: didi-ha