compose.yaml.erb

---
# bin/render_compose > compose.massive.yaml
#
# https://developer.redis.com/operate/redis-at-scale/talking-to-redis/initial-tuning/
# https://github.com/redis/redis/blob/unstable/redis.conf
services:
  node001: &node
    image: "redis:${REDIS_VERSION:-7}"
    command: >
      redis-server
      --maxmemory                       32mb
      --maxmemory-policy                allkeys-lru
      --maxmemory-clients               32%
      --maxclients                      256
      --tcp-backlog                     1024
      --timeout                         0
      --tcp-keepalive                   300
      --save                            ""
      --rdb-del-sync-files              no
      --replica-serve-stale-data        yes
      --replica-read-only               yes
      --repl-backlog-size               2mb
      --repl-backlog-ttl                0
      --repl-disable-tcp-nodelay        yes
      --repl-diskless-sync              yes
      --repl-diskless-sync-delay        0
      --repl-diskless-sync-max-replicas 0
      --repl-diskless-load              on-empty-db
      --repl-ping-replica-period        60
      --repl-timeout                    300
      --min-replicas-to-write           0
      --min-replicas-max-lag            0
      --shutdown-timeout                0
      --shutdown-on-sigint              nosave force now
      --shutdown-on-sigterm             nosave force now
      --client-output-buffer-limit      replica 0 0 0
      --client-query-buffer-limit       4mb
      --appendonly                      no
      --appendfsync                     no
      --cluster-enabled                 yes
      --cluster-config-file             nodes.conf
      --cluster-node-timeout            300000
      --cluster-replica-validity-factor 5
    restart: "${RESTART_POLICY:-always}"
    healthcheck:
      test: ["CMD", "redis-cli", "ping"]
      interval: "7s"
      timeout: "5s"
      retries: 10
    ports:
      - "<%= port %>:<%= port %>"
<% (2..n).each do |i| %>
  node<%= sprintf('%03d', i) %>:
    <<: *node
    ports:
      - "<%= port + i - 1 %>:<%= port %>"
<% end %>
  clustering:
    image: "redis:${REDIS_VERSION:-7}"
    command: >
      bash -c "apt-get update > /dev/null
      && apt-get install --no-install-recommends --no-install-suggests -y dnsutils > /dev/null
      && rm -rf /var/lib/apt/lists/*
      && yes yes | redis-cli --cluster create
<% n.times do |i| %>
      $$(dig node<%= sprintf('%03d', i + 1) %> +short):<%= port %>
<% end %>
      --cluster-replicas <%= (n - shards) / shards %>"
    depends_on:
<% n.times do |i| %>
      node<%= sprintf('%03d', i + 1) %>:
        condition: service_healthy
<% end %>