How to install Elasticsearch on CentOS / Red Hat

Elasticsearch packages are provided by Elasticsearch B.V.. Elasticsearch is a Java application, so you'll have to install a Java Runtime Environment prior to installing Elasticsearch binaries for things to work.

1. Install the latest Java Runtime Environment.

   # yum install --assumeyes java-1.8.0-openjdk

2. Download and install the public signing key Elasticsearch repository.

   # rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch

3. Create and add Elasticsearch repository information into /etc/yum.repos.d/elasticsearch.repo.

   # cat >> /etc/yum.repos.d/elasticsearch.repo <<EOF
   [elasticsearch-6.x]
   name=Elasticsearch repository for 6.x packages
   baseurl=https://artifacts.elastic.co/packages/6.x/yum
   gpgcheck=1
   gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
   enabled=1
   autorefresh=1
   type=rpm-md
   EOF

4. Install Elasticsearch package along with dependencies.

   # yum install --assumeyes elasticsearch
   ##### snipped
   ============================================================================
    Package            Arch        Version        Repository              Size
   ============================================================================
   Installing:
    elasticsearch      noarch      6.4.0-1        elasticsearch-6.x       93 M
   
   Transaction Summary
   ============================================================================
   Install  1 Package
   ##### snipped

   Even though yum supposedly resolve and install package dependencies, elasticsearch might not list java as a dependency thus you might come to this error if you don't manually install java as in the previous step.

   Running transaction
   which: no java in (/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin)
   could not find java; set JAVA_HOME or ensure java is in PATH
   error: %pre(elasticsearch-0:6.4.0-1.noarch) scriptlet failed, exit status 1
   Error in PREIN scriptlet in rpm package elasticsearch-6.4.0-1.noarch
     Verifying  : elasticsearch-6.4.0-1.noarch                             1/1
   
   Failed:
     elasticsearch.noarch 0:6.4.0-1

5. Configure Elasticsearch if necessary by editing /etc/elasticsearch/elasticsearch.yml.
   1. Listen to host's IP Address to enable connection from remote host.

      network.host: 0.0.0.0

6. Configure firewall for Elasticsearch service.
   1. Enable network access to port 9200and 9300.

      # firewall-cmd --permanent --add-port=9200/tcp
      success
      # firewall-cmd --permanent --add-port=9300/tcp
      success

   2. Reload firewall rules and keep state information.

      # firewall-cmd --reload
      success

7. Configure Elasticsearch service to automatically start during boot.

   # systemctl enable elasticsearch
   Created symlink from /etc/systemd/system/multi-user.target.wants/elasticsearch.service to /usr/lib/systemd/system/elasticsearch.service.

8. Start Elasticsearch service.

   # systemctl start elasticsearch

   The service will take a while to start

9. Test if installation is successful.

   $ curl 127.0.0.1:9200
   {
     "name" : "CbbCFrX",
     "cluster_name" : "elasticsearch",
     "cluster_uuid" : "IfiakkGkTXy20Xncr_ZZXw",
     "version" : {
       "number" : "6.4.0",
       "build_flavor" : "default",
       "build_type" : "rpm",
       "build_hash" : "595516e",
       "build_date" : "2018-08-17T23:18:47.308994Z",
       "build_snapshot" : false,
       "lucene_version" : "7.4.0",
       "minimum_wire_compatibility_version" : "5.6.0",
       "minimum_index_compatibility_version" : "5.0.0"
     },
     "tagline" : "You Know, for Search"
   }

   You will not be able to connect immediately to Elasticsearch because the service takes quite a while to start and will get the following error if you try to connect immediately.

   curl 127.0.0.1:9200
   curl: (7) Failed to connect to 127.0.0.1 port 9200: Connection refused