How to install Elasticsearch on Ubuntu or Debian

Elasticsearch is available on Github but is not available in the default apt repository for Ubuntu or Debian. However, Elastic, the company behind Elasticsearch, hosts a public repository that you can add to your system to install Elasticsearch via apt.

It is developed using Java; thus, you'll need to install Java Runtime Environment before installing Elasticsearch. Both Java Runtime Environment and Elasticsearch can be installed from the terminal using apt.

1. Add GPG key of Elasticsearch's repository.

   $ wget --quiet --output-document=- https://artifacts.elastic.co/GPG-KEY-elasticsearch | gpg --dearmor | sudo tee /usr/share/keyrings/elasticsearch-archive-keyring.gpg
   [sudo] password for user:

2. Add Elasticsearch's repository to apt's.

   $ echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-7.x.list
   deb https://artifacts.elastic.co/packages/7.x/apt stable main
   [sudo] password for user:
   deb https://artifacts.elastic.co/packages/7.x/apt stable main

3. Update list of available packages from the newly added repository.

   $ sudo apt update
   Hit:1 https://artifacts.elastic.co/packages/7.x/apt stable InRelease
   Hit:2 http://archive.ubuntu.com/ubuntu hirsute InRelease
   Get:3 http://security.ubuntu.com/ubuntu hirsute-security InRelease [101 kB]
   Get:4 http://archive.ubuntu.com/ubuntu hirsute-updates InRelease [109 kB]
   Hit:5 http://archive.ubuntu.com/ubuntu hirsute-backports InRelease 
   Fetched 209 kB in 1s (157 kB/s)                          
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   All packages are up to date.

4. Install latest Java Runtime Environment.

   $ sudo apt install --assume-yes default-jre
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   The following additional packages will be installed:
     ca-certificates-java default-jre-headless fonts-dejavu-extra java-common
     libatk-wrapper-java libatk-wrapper-java-jni openjdk-11-jre
     openjdk-11-jre-headless
   Suggested packages:
     fonts-ipafont-gothic fonts-ipafont-mincho fonts-wqy-microhei
     | fonts-wqy-zenhei
   The following NEW packages will be installed:
     ca-certificates-java default-jre default-jre-headless fonts-dejavu-extra
     java-common libatk-wrapper-java libatk-wrapper-java-jni openjdk-11-jre
     openjdk-11-jre-headless
   0 upgraded, 9 newly installed, 0 to remove and 0 not upgraded.
   Need to get 39.6 MB of archives.
   After this operation, 179 MB of additional disk space will be used.
   ##### snipped

5. Install Elasticsearch package using apt.

   $ sudo apt install --assume-yes elasticsearch
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   The following NEW packages will be installed:
     elasticsearch
   0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
   Need to get 326 MB of archives.
   ##### snipped

6. Enable access to port 9200 and 9300 from the local firewall.

   $ sudo ufw allow 9200
   Rules updated
   Rules updated (v6)
   $ sudo ufw allow 9300
   Rules updated
   Rules updated (v6)

7. Open Elasticsearch configuration file using your preferred text editor to edit configuration options if necessary.

   $ sudo vi /etc/elasticsearch/elasticsearch.yml

   Listen to host's IP address to enable connection from remote host or use 0.0.0.0 to listen on all available IP addresses in your system.

   network.host: 0.0.0.0

   Related: How to install Kibana on Ubuntu or Debian

8. Configure Elasticsearch to automatically start during boot.

   $ sudo systemctl enable elasticsearch
   Synchronizing state of elasticsearch.service with SysV service script with /lib/systemd/systemd-sysv-install.
   Executing: /lib/systemd/systemd-sysv-install enable elasticsearch
   Created symlink /etc/systemd/system/multi-user.target.wants/elasticsearch.service → /lib/systemd/system/elasticsearch.service.

9. Start Elasticsearch service.

    $ sudo systemctl start elasticsearch

10. Query Elasticsearch service to test if installation was successful.

    $ curl 127.0.0.1:9200
    {
      "name" : "host",
      "cluster_name" : "elasticsearch",
      "cluster_uuid" : "NqCDFByvRKWPcjO1z09hmg",
      "version" : {
        "number" : "7.12.1",
        "build_flavor" : "default",
        "build_type" : "deb",
        "build_hash" : "3186837139b9c6b6d23c3200870651f10d3343b7",
        "build_date" : "2021-04-20T20:56:39.040728659Z",
        "build_snapshot" : false,
        "lucene_version" : "8.8.0",
        "minimum_wire_compatibility_version" : "6.8.0",
        "minimum_index_compatibility_version" : "6.0.0-beta1"
      },
      "tagline" : "You Know, for Search"
    }

    You will get the following error if you immediately test the service after starting it up because Elasticsearch takes a while to start.

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