Install Elasticsearch 6.x on Ubuntu 18.04

Requirements

Elasticsearch 6.x requires Java 8 or later. If you don't have Java installed yet install it:

apt-get install openjdk-8-jre-headless

The Elasticsearch APT repository is using HTTPS. For this reason, you need to install the following package.

apt-get install apt-transport-https

Install Elasticsearch

Add official the APT repository to your sources.list

echo "deb https://artifacts.elastic.co/packages/6.x/apt stable main" > /etc/apt/sources.list.d/elastic-6.x.list
wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | apt-key add -
apt-get update

Install

apt-get install elasticsearch

Configure Elasticsearch

In this case, we are going to setup a standalone Elasticsearch system.

Open the file /etc/elasticsearch/elasticsearch.yml to adjust the following values

#Set the name of your Elasticsearch Cluster
cluster.name: statusengine

# Set the name of the current node
node.name: elastic01

#Path where Elasticsearch should store data
path.data: /var/lib/elasticsearch

#Path where Elasticsearch should store log files
path.logs: /var/log/elasticsearch

#You need at least one master node inside
#of your Elasticsearch Cluster
node.master: true

#You need at least one node inside
#of your Elasticsearch Cluster, that holds your data
node.data: true

If one of the listed options is missing in your default config, just add it .

Start Elasticsearch

systemctl enable elasticsearch.service
systemctl start elasticsearch.service

By default Elasticsearch will listen on localhost:9200 and localhost:9300.

You can change this or run an HTTP reverse proxy (for example nginx) in front of Elasticsearch.

(It could take up to 60 seconds until Elasticsearch will show up in netstat)

root@bionic:~# netstat -tulpen | grep java
tcp6       0      0 127.0.0.1:9200          :::*                    LISTEN      113        49099      12058/java
tcp6       0      0 ::1:9200                :::*                    LISTEN      113        49098      12058/java
tcp6       0      0 127.0.0.1:9300          :::*                    LISTEN      113        49061      12058/java
tcp6       0      0 ::1:9300                :::*                    LISTEN      113        49046      12058/java

Test Elasticsearch

To check if your installation of Elasticsearch is running, you can run a simple status query against it.

curl -X GET "http://localhost:9200"

You should get an result like this:

{
  "name" : "elastic01",
  "cluster_name" : "statusengine",
  "cluster_uuid" : "BmTwQnJqQVKm89BA5nb9Eg",
  "version" : {
    "number" : "6.4.0",
    "build_flavor" : "default",
    "build_type" : "deb",
    "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"
}

Setup Cerebro

Cerebro (previously known as kopf), is an web based admin tool for Elasticsearch. Especially if you are new to Elasticsearch it will help you a lot!

Before you start! Please check for newer version at the official GitHub repository!

cd /tmp
wget https://github.com/lmenezes/cerebro/releases/download/v0.8.1/cerebro-0.8.1.tgz
tar xfv cerebro-0.8.1.tgz
cd cerebro-0.8.1/
mkdir -p /usr/local/share/cerebro
cp -r * /usr/local/share/cerebro/

Now you can run Cerebro using this command:

/usr/local/share/cerebro/bin/cerebro

You should now be able to access Cerebro via your Webbrowser: http://<ip-address>:9000

In addition, you can add a systemd service, to run Cerebro as service in the background. Create the file /lib/systemd/system/cerebro.service:

[Unit]
Description=Cerebro
After=syslog.target network.target

[Service]
User=root
Type=simple
Restart=on-failure
ExecStart=/usr/local/share/cerebro/bin/cerebro

[Install]
WantedBy=multi-user.target

systemctl daemon-reload
systemctl start cerebro.service