Install Elasticsearch with Debian Package

We sign all of our packages with the Elasticsearch Signing Key (PGP key D88E42B4, available from https://pgp.mit.edu) with fingerprint:

4609 5ACC 8548 582C 1A26 99A9 D27D 666C D88E 42B4

Download and install the public signing key:

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo gpg --dearmor -o /usr/share/keyrings/elasticsearch-keyring.gpg

You may need to install the apt-transport-https package on Debian before proceeding:

sudo apt-get install apt-transport-https

Save the repository definition to /etc/apt/sources.list.d/elastic-8.x.list:

echo "deb [signed-by=/usr/share/keyrings/elasticsearch-keyring.gpg] https://artifacts.elastic.co/packages/8.x/apt stable main" | sudo tee /etc/apt/sources.list.d/elastic-8.x.list

You can install the Elasticsearch Debian package with:

sudo apt-get update && sudo apt-get install elasticsearch

Duplicate sources.list entry https://artifacts.elastic.co/packages/8.x/apt/ ...`

The Debian package for Elasticsearch v8.15.3 can be downloaded from the website and installed as follows:

wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-8.15.3-amd64.deb
wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-8.15.3-amd64.deb.sha512
shasum -a 512 -c elasticsearch-8.15.3-amd64.deb.sha512 
sudo dpkg -i elasticsearch-8.15.3-amd64.deb

To configure Elasticsearch to start automatically when the system boots up, run the following commands:

sudo /bin/systemctl daemon-reload
sudo /bin/systemctl enable elasticsearch.service

Elasticsearch can be started and stopped as follows:

sudo systemctl start elasticsearch.service
sudo systemctl stop elasticsearch.service

These commands provide no feedback as to whether Elasticsearch was started successfully or not. Instead, this information will be written in the log files located in /var/log/elasticsearch/.

If you have password-protected your Elasticsearch keystore, you will need to provide systemd with the keystore password using a local file and systemd environment variables. This local file should be protected while it exists and may be safely deleted once Elasticsearch is up and running.

echo "keystore_password" > /path/to/my_pwd_file.tmp
chmod 600 /path/to/my_pwd_file.tmp
sudo systemctl set-environment ES_KEYSTORE_PASSPHRASE_fILE=/path/to/my_pwd_file.tmp
sudo systemctl start elasticsearch.service

By default the Elasticsearch service doesn’t log information in the systemd journal. To enable journalctl logging, the --quiet option must be removed from the ExecStart command line in the elasticsearch.service file.

When systemd logging is enabled, the logging information are available using the journalctl commands:

To tail the journal:

sudo journalctl -f

To list journal entries for the elasticsearch service:

sudo journalctl --unit elasticsearch

To list journal entries for the elasticsearch service starting from a given time:

sudo journalctl --unit elasticsearch --since  "2016-10-30 18:17:16"

Check man journalctl or https://www.freedesktop.org/software/systemd/man/journalctl.html for more command line options.

[2022-01-31T01:22:31,077][INfO ][o.e.n.Node               ] [instance-0000000123] starting ...
...
[2022-01-31T01:37:15,077][INfO ][o.e.n.Node               ] [instance-0000000123] stopping ...

Jan 31 01:22:30 debian systemd[1]: Starting Elasticsearch...
Jan 31 01:37:15 debian systemd[1]: elasticsearch.service: Start operation timed out. Terminating.
Jan 31 01:37:15 debian systemd[1]: elasticsearch.service: Main process exited, code=killed, status=15/TERM
Jan 31 01:37:15 debian systemd[1]: elasticsearch.service: failed with result 'timeout'.
Jan 31 01:37:15 debian systemd[1]: failed to start Elasticsearch.

You can test that your Elasticsearch node is running by sending an HTTPS request to port 9200 on localhost:

curl --cacert /etc/elasticsearch/certs/http_ca.crt -u elastic:$ELASTIC_PASSWORD https://localhost:9200 

The call returns a response like this:

{
  "name" : "Cp8oag6",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "AT69_T_DTp-1qgIJlatQqA",
  "version" : {
    "number" : "8.15.3",
    "build_type" : "tar",
    "build_hash" : "f27399d",
    "build_flavor" : "default",
    "build_date" : "2016-03-30T09:51:41.449Z",
    "build_snapshot" : false,
    "lucene_version" : "9.11.1",
    "minimum_wire_compatibility_version" : "1.2.3",
    "minimum_index_compatibility_version" : "1.2.3"
  },
  "tagline" : "You Know, for Search"
}

The /etc/elasticsearch directory contains the default runtime configuration for Elasticsearch. The ownership of this directory and all contained files are set to root:elasticsearch on package installations.

The setgid flag applies group permissions on the /etc/elasticsearch directory to ensure that Elasticsearch can read any contained files and subdirectories. All files and subdirectories inherit the root:elasticsearch ownership. Running commands from this directory or any subdirectories, such as the elasticsearch-keystore tool, requires root:elasticsearch permissions.

Elasticsearch loads its configuration from the /etc/elasticsearch/elasticsearch.yml file by default. The format of this config file is explained in Configuring Elasticsearch.

The Debian package also has a system configuration file (/etc/default/elasticsearch), which allows you to set the following parameters:

When you start Elasticsearch for the first time, TLS is configured automatically for the HTTP layer. A CA certificate is generated and stored on disk at:

/etc/elasticsearch/certs/http_ca.crt

The hex-encoded SHA-256 fingerprint of this certificate is also output to the terminal. Any clients that connect to Elasticsearch, such as the Elasticsearch Clients, Beats, standalone Elastic Agents, and Logstash must validate that they trust the certificate that Elasticsearch uses for HTTPS. fleet Server and fleet-managed Elastic Agents are automatically configured to trust the CA certificate. Other clients can establish trust by using either the fingerprint of the CA certificate or the CA certificate itself.

If the auto-configuration process already completed, you can still obtain the fingerprint of the security certificate. You can also copy the CA certificate to your machine and configure your client to use it.

Copy the fingerprint value that’s output to your terminal when Elasticsearch starts, and configure your client to use this fingerprint to establish trust when it connects to Elasticsearch.

If the auto-configuration process already completed, you can still obtain the fingerprint of the security certificate by running the following command. The path is to the auto-generated CA certificate for the HTTP layer.

openssl x509 -fingerprint -sha256 -in config/certs/http_ca.crt

The command returns the security certificate, including the fingerprint. The issuer should be Elasticsearch security auto-configuration HTTP CA.

issuer= /CN=Elasticsearch security auto-configuration HTTP CA
SHA256 fingerprint=<fingerprint>

If your library doesn’t support a method of validating the fingerprint, the auto-generated CA certificate is created in the following directory on each Elasticsearch node:

/etc/elasticsearch/certs/http_ca.crt

Copy the http_ca.crt file to your machine and configure your client to use this certificate to establish trust when it connects to Elasticsearch.

The Debian package places config files, logs, and the data directory in the appropriate locations for a Debian-based system:

bin/elasticsearch-keystore show xpack.security.http.ssl.keystore.secure_password

bin/elasticsearch-keystore show xpack.security.transport.ssl.keystore.secure_password