一、介紹
ElasticSearch是一個基於Lucene的搜索服務器。它提供了一個分布式多用戶能力的全文搜索引擎，基於RESTful web接口。Elasticsearch是用Java開發的，並作為Apache許可條款下的開放源碼發布，是當前流行的企業級搜索引擎。設計用於雲計算中，能夠達到實時搜索，穩定，可靠，快速，安裝使用方便。
二、安裝docker
本文使用的是centos7.5(CentOS-7-x86_64-Minimal-1804) 系統。
請確保本機有2G的內存。因為elasticsearch會占用1G內存。
安裝docker
yum安裝docker
yum install -y docker-io
需要添加國內鏡像源
vim /etc/docker/daemon.json
默認內容是{}，修改效果如下：
{ "registry-mirrors": ["https://registry.docker-cn.com"] }
重啟docker服務
systemctl restart docker
安裝docker命令補全工具
yum install -y bash-completion
注意:必須要退出終端，重新登錄一次才能生效。
下載centos系統鏡像
docker pull centos
這個鏡像就是centos7的
三、安裝elasticsearch
下載rpm安裝就可以了
https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.2.4.rpm
使用centos鏡像啟動一個容器
docker run -it docker.io/centos /bin/bash
進入容器之后，先安裝wget和java，並清理rpm包
yum install -y wget java-1.8.0-openjdk && yum clean all
下載elasticsearch的rpm包並安裝
rpm -ivh elasticsearch-6.2.4.rpm && rm -f elasticsearch-6.2.4.rpm
修改配置文件
sed -i '55s/#network.host: 192.168.0.1/network.host: 0.0.0.0/g' /etc/elasticsearch/elasticsearch.yml sed -i '59s/#http.port: 9200/http.port: 9200/g' /etc/elasticsearch/elasticsearch.yml
啟動elasticsearch服務
runuser -s /bin/bash -l elasticsearch -c "/usr/share/elasticsearch/bin/elasticsearch"
注意：不能使用systemctl命令啟動elasticsearch服務，必須要以特權模式運行才行！
比如 docker run -it docker.io/centos privileged=true /bin/bash
四、編寫Dockerfile
Dockerfile
新建一個空目錄，編譯文件Dockerfile
mkdir /opt/elasticsearch vi /opt/elasticsearch/Dockerfile
內容如下：
FROM centos RUN yum install -y wget java-1.8.0-openjdk && yum clean all && \ wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.2.4.rpm && \ rpm -ivh elasticsearch-6.2.4.rpm && rm -f elasticsearch-6.2.4.rpm && \ sed -i '55s/#network.host: 192.168.0.1/network.host: 0.0.0.0/g' /etc/elasticsearch/elasticsearch.yml && \ sed -i '59s/#http.port: 9200/http.port: 9200/g' /etc/elasticsearch/elasticsearch.yml EXPOSE 9200 ENTRYPOINT runuser -s /bin/bash -l elasticsearch -c "/usr/share/elasticsearch/bin/elasticsearch"
注意：每執行一次RUN，鏡像就會增加一層。層數越多，鏡像體積越大。
為了避免多次RUN，把相關命令統一到一個RUN中。
EXPOSE 9200 表示要暴露的端口號
ENTRYPOINT 表示鏡像run起來之后，默認要執行的命令
runuser 指定用戶執行命令。
- -s 指定環境變量
- -l 指定用戶
- -c 執行的命令
編排鏡像
docker build -t elasticsearch /opt/elasticsearch
啟動容器
docker run -it elasticsearch
默認會直接調用命令 runuser -s /bin/bash -l elasticsearch -c "/usr/share/elasticsearch/bin/elasticsearch"
輸出如下：
runuser: warning: cannot change directory to /home/elasticsearch: No such file or directory OpenJDK 64-Bit Server VM warning: If the number of processors is expected to increase from one, then you should configure the number of parallel GC threads appropriately using -XX:ParallelGCThreads=N [2018-11-07T10:18:54,057][INFO ][o.e.n.Node ] [] initializing ... [2018-11-07T10:18:54,198][INFO ][o.e.e.NodeEnvironment ] [qDmU4u_] using [1] data paths, mounts [[/ (rootfs)]], net usable_space [15gb], net total_space [16.9gb], types [rootfs] [2018-11-07T10:18:54,198][INFO ][o.e.e.NodeEnvironment ] [qDmU4u_] heap size [1015.6mb], compressed ordinary object pointers [true] [2018-11-07T10:18:54,202][INFO ][o.e.n.Node ] node name [qDmU4u_] derived from node ID [qDmU4u_NTNKmpXVV-5vlEQ]; set [node.name] to override [2018-11-07T10:18:54,202][INFO ][o.e.n.Node ] version[6.2.4], pid[5], build[ccec39f/2018-04-12T20:37:28.497551Z], OS[Linux/3.10.0-862.el7.x86_64/amd64], JVM[Oracle Corporation/OpenJDK 64-Bit Server VM/1.8.0_191/25.191-b12] [2018-11-07T10:18:54,202][INFO ][o.e.n.Node ] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -XX:-OmitStackTraceInFastThrow, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch.C8ZXNqCd, -XX:+HeapDumpOnOutOfMemoryError, -XX:HeapDumpPath=/var/lib/elasticsearch, -XX:+PrintGCDetails, -XX:+PrintGCDateStamps, -XX:+PrintTenuringDistribution, -XX:+PrintGCApplicationStoppedTime, -Xloggc:/var/log/elasticsearch/gc.log, -XX:+UseGCLogFileRotation, -XX:NumberOfGCLogFiles=32, -XX:GCLogFileSize=64m, -Des.path.home=/usr/share/elasticsearch, -Des.path.conf=/etc/elasticsearch] [2018-11-07T10:18:55,827][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [aggs-matrix-stats] [2018-11-07T10:18:55,827][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [analysis-common] [2018-11-07T10:18:55,827][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [ingest-common] [2018-11-07T10:18:55,831][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [lang-expression] [2018-11-07T10:18:55,831][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [lang-mustache] [2018-11-07T10:18:55,831][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [lang-painless] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [mapper-extras] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [parent-join] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [percolator] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [rank-eval] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [reindex] [2018-11-07T10:18:55,832][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [repository-url] [2018-11-07T10:18:55,833][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [transport-netty4] [2018-11-07T10:18:55,833][INFO ][o.e.p.PluginsService ] [qDmU4u_] loaded module [tribe] [2018-11-07T10:18:55,833][INFO ][o.e.p.PluginsService ] [qDmU4u_] no plugins loaded [2018-11-07T10:19:00,949][INFO ][o.e.d.DiscoveryModule ] [qDmU4u_] using discovery type [zen] [2018-11-07T10:19:02,075][INFO ][o.e.n.Node ] initialized [2018-11-07T10:19:02,075][INFO ][o.e.n.Node ] [qDmU4u_] starting ... [2018-11-07T10:19:02,531][INFO ][o.e.t.TransportService ] [qDmU4u_] publish_address {172.17.0.2:9300}, bound_addresses {[::]:9300} [2018-11-07T10:19:02,567][INFO ][o.e.b.BootstrapChecks ] [qDmU4u_] bound or publishing to a non-loopback address, enforcing bootstrap checks [2018-11-07T10:19:05,811][INFO ][o.e.c.s.MasterService ] [qDmU4u_] zen-disco-elected-as-master ([0] nodes joined), reason: new_master {qDmU4u_}{qDmU4u_NTNKmpXVV-5vlEQ}{Terj8KYoQvWwHYsUYkNNyA}{172.17.0.2}{172.17.0.2:9300} [2018-11-07T10:19:05,829][INFO ][o.e.c.s.ClusterApplierService] [qDmU4u_] new_master {qDmU4u_}{qDmU4u_NTNKmpXVV-5vlEQ}{Terj8KYoQvWwHYsUYkNNyA}{172.17.0.2}{172.17.0.2:9300}, reason: apply cluster state (from master [master {qDmU4u_}{qDmU4u_NTNKmpXVV-5vlEQ}{Terj8KYoQvWwHYsUYkNNyA}{172.17.0.2}{172.17.0.2:9300} committed version [1] source [zen-disco-elected-as-master ([0] nodes joined)]]) [2018-11-07T10:19:05,887][INFO ][o.e.h.n.Netty4HttpServerTransport] [qDmU4u_] publish_address {172.17.0.2:9200}, bound_addresses {[::]:9200} [2018-11-07T10:19:05,887][INFO ][o.e.n.Node ] [qDmU4u_] started [2018-11-07T10:19:05,897][INFO ][o.e.g.GatewayService ] [qDmU4u_] recovered [0] indices into cluster_state
它會一值hold住，監聽9200端口
但是一般，我們需要將本機和容器做一個端口映射，要這樣啟動容器
docker run -p 9200:9200 -d -it el
-p 表示端口映射，hostPort : containerPort，左邊是本機的，右邊是容器的
-d 表示后台運行
注意：這個2個參數要寫在前面，不能寫在后面
等待10秒，查看端口狀態
[root@localhost el]# netstat -anpt Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 813/sshd tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1190/master tcp 0 0 192.168.91.133:22 192.168.91.1:56367 ESTABLISHED 11374/sshd: root@pt tcp6 0 0 :::9200 :::* LISTEN 17942/docker-proxy- tcp6 0 0 :::22 :::* LISTEN 813/sshd tcp6 0 0 ::1:25 :::* LISTEN 1190/master
通過以上信息，就可以看到端口起來了
訪問url
http://192.168.91.133:9200/
頁面輸出：
{ "name" : "-sawdKe", "cluster_name" : "elasticsearch", "cluster_uuid" : "_7kUiLEyQBSnLQSOGxijtw", "version" : { "number" : "6.2.4", "build_hash" : "ccec39f", "build_date" : "2018-04-12T20:37:28.497551Z", "build_snapshot" : false, "lucene_version" : "7.2.1", "minimum_wire_compatibility_version" : "5.6.0", "minimum_index_compatibility_version" : "5.0.0" }, "tagline" : "You Know, for Search" }
備注：
如果不使用容器安裝elasticsearch，直接使用以下命令，就可以啟動elasticsearch
systemctl daemon-reload
systemctl start elasticsearch.service
systemctl enable elasticsearch.service
不要天真的以為，它就是以root用戶運行的
看/usr/lib/systemd/system/elasticsearch 文件，它里面定義了運行用戶是elasticsearch
所以實際運行用戶還是elasticsearch