搭建 elasticsearch 叢集

本文記錄搭建 elasticsearch cluster 的過程。

對於 ELK 的應用及操作都練習很多了，日常工作常用到，但如果是從零開始，這我反倒是沒有經驗，這篇其實就是我自己的摸索過程

因為情境是搭建在三台虛擬機上，每台一個elasticsearch節點，所以勢必不可能用一份 docker-compose.yml直接結案 我的錯誤嘗試很多，所以不打算全都列出來，所以我大概提一下重點

node1

.env

# .env
# Elasticsearch connection settings
ELASTIC_HOST=https://localhost:9200
ELASTIC_USERNAME=elastic
ELASTIC_PASSWORD=test123

docker-compose.yml

services:
  setup:
    container_name: setup
    image: docker.elastic.co/elasticsearch/elasticsearch:8.6.1
    volumes:
      - ./certs:/usr/share/elasticsearch/config/certs
    user: "0"
    command: >
      bash -c '
        if [ x${ELASTIC_PASSWORD} == x ]; then
          echo "Set the ELASTIC_PASSWORD environment variable in the .env file";
          exit 1;
        fi;
        if [ ! -f config/certs/ca.zip ]; then
          echo "Creating CA";
          bin/elasticsearch-certutil ca --silent --pem -out config/certs/ca.zip;
          unzip config/certs/ca.zip -d config/certs;
        fi;
        if [ ! -f config/certs/certs.zip ]; then
          echo "Creating certs";
          echo -ne \
          "instances:\n"\
          "  - name: es01\n"\
          "    dns:\n"\
          "      - es01\n"\
          "      - localhost\n"\
          "    ip:\n"\
          "      - 127.0.0.1\n"\
          "      - 172.27.98.106\n"\
          "  - name: es02\n"\
          "    dns:\n"\
          "      - es02\n"\
          "      - localhost\n"\
          "    ip:\n"\
          "      - 127.0.0.1\n"\
          "      - 172.27.106.246\n"\
          "  - name: es03\n"\
          "    dns:\n"\
          "      - es03\n"\
          "      - localhost\n"\
          "    ip:\n"\
          "      - 127.0.0.1\n"\
          "      - 172.27.102.224\n"\
          > config/certs/instances.yml;
          bin/elasticsearch-certutil cert --silent --pem -out config/certs/certs.zip --in config/certs/instances.yml --ca-cert config/certs/ca/ca.crt --ca-key config/certs/ca/ca.key;
          unzip config/certs/certs.zip -d config/certs;
        fi;
        echo "Setting file permissions"
        chown -R root:root config/certs;
        find . -type d -exec chmod 750 \{\} \;;
        find . -type f -exec chmod 640 \{\} \;;
        echo "Waiting for Elasticsearch availability";
        until curl -s --cacert config/certs/ca/ca.crt https://es01:9200 | grep -q "missing authentication credentials"; do sleep 30; done;
        echo "Setting kibana_system password";
        until curl -s -X POST --cacert config/certs/ca/ca.crt -u "elastic:${ELASTIC_PASSWORD}" -H "Content-Type: application/json" https://es01:9200/_security/user/kibana_system/_password -d "{\"password\":\"kibana123\"}" | grep -q "^{}"; do sleep 10; done;
        echo "All done!";
      '
    healthcheck:
      test: ["CMD-SHELL", "[ -f config/certs/es01/es01.crt ]"]
      interval: 1s
      timeout: 5s
      retries: 120
  es01:
    container_name: es01
    depends_on:
      setup:
        condition: service_healthy
    image: docker.elastic.co/elasticsearch/elasticsearch:8.6.1
    ports:
      - 9200:9200
      - 9300:9300
    volumes:
      - ./certs:/usr/share/elasticsearch/config/certs
      - ./esdata:/usr/share/elasticsearch/data
    environment:
      - node.name=es01
      - network.publish_host=172.27.98.106
      - cluster.name=es-cluster
      - cluster.initial_master_nodes=es01
      - discovery.seed_hosts=172.27.98.106,172.27.106.246,172.27.102.224
      - ELASTIC_PASSWORD=${ELASTIC_PASSWORD}
      - bootstrap.memory_lock=true
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.http.ssl.key=certs/es01/es01.key
      - xpack.security.http.ssl.certificate=certs/es01/es01.crt
      - xpack.security.http.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.key=certs/es01/es01.key
      - xpack.security.transport.ssl.certificate=certs/es01/es01.crt
      - xpack.security.transport.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.verification_mode=certificate
      - xpack.license.self_generated.type=basic
      - cluster.routing.allocation.disk.watermark.low=2gb
      - cluster.routing.allocation.disk.watermark.high=1gb
      - cluster.routing.allocation.disk.watermark.flood_stage=512mb
    mem_limit: 1073741824
    ulimits:
      memlock:
        soft: -1
        hard: -1
    healthcheck:
      test:
        [
          "CMD-SHELL",
          "curl -s --cacert config/certs/ca/ca.crt https://localhost:9200 | grep -q 'missing authentication credentials'",
        ]
      interval: 10s
      timeout: 10s
      retries: 120
  kibana:
    container_name: kibana
    depends_on:
      es01:
        condition: service_healthy
    image: docker.elastic.co/kibana/kibana:8.6.1
    volumes:
      - ./certs:/usr/share/kibana/config/certs
      - ./kibanadata:/usr/share/kibana/data
    ports:
      - 5601:5601
    user: "1000"
    environment:
      - SERVERNAME=kibana
      - theme:darkMode=true
      - ELASTICSEARCH_HOSTS=https://es01:9200
      - ELASTICSEARCH_USERNAME=kibana_system
      - ELASTICSEARCH_PASSWORD=kibana123
      - ELASTICSEARCH_SSL_CERTIFICATEAUTHORITIES=config/certs/ca/ca.crt
      - xpack.security.encryptionKey=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
      - xpack.encryptedSavedObjects.encryptionKey=bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
      - xpack.reporting.encryptionKey=cccccccccccccccccccccccccccccccc

    mem_limit: 1073741824
    healthcheck:
      test:
        [
          "CMD-SHELL",
          "curl -s -I http://localhost:5601 | grep -q 'HTTP/1.1 302 Found'",
        ]
      interval: 10s
      timeout: 10s
      retries: 120

上面這一段有一個很重要的是 setup 的部分，這是一個獨立的服務，用來建立憑證。

node2

.env

# .env
ELASTIC_HOST=https://localhost:9200
ELASTIC_USERNAME=elastic
ELASTIC_PASSWORD=test123

docker-compose.yml

services:
  es02:
    container_name: es02
    image: docker.elastic.co/elasticsearch/elasticsearch:8.6.1
    ports:
      - 9200:9200
      - 9300:9300
    volumes:
      - ./certs:/usr/share/elasticsearch/config/certs
      - ./esdata:/usr/share/elasticsearch/data
    environment:
      - node.name=es02
      - network.publish_host=172.27.106.246
      - cluster.name=es-cluster
      - discovery.seed_hosts=172.27.98.106,172.27.106.246,172.27.102.224
      - ELASTIC_PASSWORD=${ELASTIC_PASSWORD}
      - bootstrap.memory_lock=true
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.http.ssl.key=certs/es02/es02.key
      - xpack.security.http.ssl.certificate=certs/es02/es02.crt
      - xpack.security.http.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.key=certs/es02/es02.key
      - xpack.security.transport.ssl.certificate=certs/es02/es02.crt
      - xpack.security.transport.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.verification_mode=certificate
      - xpack.license.self_generated.type=basic
      - cluster.routing.allocation.disk.watermark.low=2gb
      - cluster.routing.allocation.disk.watermark.high=1gb
      - cluster.routing.allocation.disk.watermark.flood_stage=512mb
    mem_limit: 1073741824
    ulimits:
      memlock:
        soft: -1
        hard: -1
    healthcheck:
      test:
        [
          "CMD-SHELL",
          "curl -s --cacert config/certs/ca/ca.crt https://localhost:9200 | grep -q 'missing authentication credentials'",
        ]
      interval: 10s
      timeout: 10s
      retries: 120

node3

.env

# .env
ELASTIC_HOST=https://localhost:9200
ELASTIC_USERNAME=elastic
ELASTIC_PASSWORD=test123

docker-compose.yml

services:
  es03:
    container_name: es03
    image: docker.elastic.co/elasticsearch/elasticsearch:8.6.1
    ports:
      - 9200:9200
      - 9300:9300
    volumes:
      - ./certs:/usr/share/elasticsearch/config/certs
      - ./esdata:/usr/share/elasticsearch/data
    environment:
      - node.name=es03
      - cluster.name=es-cluster
      - network.publish_host=172.27.102.224
      - cluster.name=es-cluster
      - discovery.seed_hosts=172.27.98.106,172.27.106.246,172.27.102.224
      - ELASTIC_PASSWORD=${ELASTIC_PASSWORD}
      - bootstrap.memory_lock=true
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.http.ssl.key=certs/es03/es03.key
      - xpack.security.http.ssl.certificate=certs/es03/es03.crt
      - xpack.security.http.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.key=certs/es03/es03.key
      - xpack.security.transport.ssl.certificate=certs/es03/es03.crt
      - xpack.security.transport.ssl.certificate_authorities=certs/ca/ca.crt
      - xpack.security.transport.ssl.verification_mode=certificate
      - xpack.license.self_generated.type=basic
      - cluster.routing.allocation.disk.watermark.low=2gb
      - cluster.routing.allocation.disk.watermark.high=1gb
      - cluster.routing.allocation.disk.watermark.flood_stage=512mb
    mem_limit: 1073741824
    ulimits:
      memlock:
        soft: -1
        hard: -1
    healthcheck:
      test:
        [
          "CMD-SHELL",
          "curl -s --cacert config/certs/ca/ca.crt https://localhost:9200 | grep -q 'missing authentication credentials'",
        ]
      interval: 10s
      timeout: 10s
      retries: 120

重點說明

因為這些筆記已經寫了有半年之久，今天才整理，所以我其實已經忘記了這是我第幾次嘗試後，寫的手動SOP 但印象是node1的 docker-compose.yml裡面有 setup的部分，其實已經把這些東西都自動化作掉了。 不過還是紀錄一下，如果需要手動作的話，大概會有哪些環節。

建立minimal security

  1. 加入xpack.security.enabled: true

查看節點

http://172.27.106.193:9200/_cat/nodes?v

第一次建立密碼

docker exec -it elasticsearch bash
./bin/elasticsearch-setup-passwords interactive

kibana 加入帳密設定

elasticsearch.username: kibana_system
elasticsearch.password: change-me

建立憑證(讓node 互相以 TLS 溝通)

  • 建立CA
  • 使用CA建立憑證並放到node中
  • 添加設定到yml，並重啟節點

node1 進入節點並建立CA、產生憑證

docker exec -it elasticsearch bash

# 建立CA
./bin/elasticsearch-certutil ca
# 接著用ca來建立憑證
./bin/elasticsearch-certutil cert --ca elastic-stack-ca.p12

在宿主機創建臨時目錄

mkdir ~/elastic-certs && cd ~/elastic-certs

使用 Elasticsearch 容器生成 CA 和節點證書（無需啟動容器）

docker run –rm -v $(pwd):/certs docker.elastic.co/elasticsearch/elasticsearch:8.17.4
bin/elasticsearch-certutil cert –silent –pem –in /usr/share/elasticsearch/config/certificates/instances.yml –out /certs/certs.zip

解壓證書文件

unzip certs.zip -d certs

將產生的憑證從容器複製出來，調整權限方便讓其他節點複製

docker cp elasticsearch:/usr/share/elasticsearch/elastic-certificates.p12 .
chmod 777 elastic-certificates.p12
# 接著把憑證放到 /home/art/es-auth/cert

node2 , node 3

先把憑證的目錄建好，放在 /home/art/es-auth/cert

sudo scp art@172.27.106.193:/home/art/es-auth/cert/elastic-certificates.p12 .

修改所有節點設定檔，加入下面設定 node1,2,3的 elasticsearch.yml

# 產生金鑰後加入下面設定
xpack.security.transport.ssl.enabled: true
xpack.security.transport.ssl.verification_mode: certificate
xpack.security.transport.ssl.client_authentication: required
xpack.security.transport.ssl.keystore.path: elastic-certificates.p12
xpack.security.transport.ssl.truststore.path: elastic-certificates.p12

讓 docker-compose 掛載憑證

    volumes:
      - /home/art/es-auth/cert/elastic-certificates.p12:/usr/share/elasticsearch/config/elastic-certificates.p12

參考資料

  1. # 為 Elasticsearch 設定最低安全性
  2. https://ithelp.ithome.com.tw/articles/10329516
  3. https://github.com/cr7258/elasticsearch-mcp-server/blob/main/docker-compose-elasticsearch.yml