Elasticsearch

Elasticsearch is developed specifically with search and layered navigation in mind. Because of this Elasticsearch is much more suitable for e-commerce sites navigation and search features. Traditional solutions usually use MySQL, this results in a much bigger impact on the server load and negative performance of the application.

Elasticsearch is controlled using the Hipex CLI docker commands. For the rest of this tutorial we assume you are familiar with the docker basics.

Service configuratie

First we configure the service using a docker-compose.yml. In this file the elasticsearch version and port is defined. In these examples version 7.8 and port 19200 is used.

We recommend using a seperate folder for your elasticsearch instance so your configuration file would end up in: ~/elasticsearch/docker-compose.yml.

version: "3.2"

services:
    elasticsearch:
        image: elasticsearch:7.8.0
        restart: "always"
        environment:
            - LOG4J_FORMAT_MSG_NO_LOOKUPS=true
            - discovery.type=single-node
            - ES_JAVA_OPTS=-Xmx3g
            - xpack.security.enabled=true
            - xpack.security.audit.enabled=true
            - ELASTIC_PASSWORD=password
        volumes:
        - ./data:/var/elasticsearch
        ports:
        - "19200:9200"

Since we are using a mounted volume we also need to create the data directory.

cd ~/elasticsearch/
mkdir data
chmod 644 data

Now the service can be started using docker:compose:up.

cd ~/elasticsearch/
hipex docker:compose:up --detach

Security test Log4j

To check if the environment variables are set correctly, you can run the test below:
If the value is true, this is set correctly.

[16:29:36]-[Servername]-[Sshuser]-[~/elasticsearch]$ hipex docker:compose:exec elasticsearch bash
[root@5c3facac6acc elasticsearch]# echo $LOG4J_FORMAT_MSG_NO_LOOKUPS
true

With the command exit you can exit the docker container again.

Memory settings

By default ElasticSearch allocates half of the available memory on the server. To prevent this from happening you can add an extra variable to the Docker configuration. If you add the variable '- ESJAVAOPTS=-Xmx3g' to the Docker compose file, ElasticSearch will allocate a maximum of 3GB of memory. If more memory is needed/desired you can increase the amount of GB.

Port bind error

When receiving a Bind for 0.0.0.0:19200 failed: port is already allocated error, the configured port 19200 is already in use and another port must be configured.

Usage

Now you should be able to access your elasticsearch instance on port 19200.

curl localhost:19200


{
  "name" : "512decbc664a",
  "cluster_name" : "docker-cluster",
  "cluster_uuid" : "hZ1_YRATQdOOw1tIz4nn2Q",
  "version" : {
    "number" : "7.8.0",
    "build_flavor" : "default",
    "build_type" : "docker",
    "build_hash" : "757314695644ea9a1dc2fecd26d1a43856725e65",
    "build_date" : "2020-06-14T19:35:50.234439Z",
    "build_snapshot" : false,
    "lucene_version" : "8.5.1",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

Plugins

When you need plugins like analysis-icu or analysis-phonetic for example the suggested way to do this is to create your own docker image like this:

FROM elasticsearch:6.8.0

RUN elasticsearch-plugin install -b analysis-icu
RUN elasticsearch-plugin install -b analysis-phonetic

If building your own docker image is not an option you can overwrite the default startup command to install them at startup.

version: "3.2"
services:
    elasticsearch:
        image: elasticsearch:7.8.0
        restart: "always"
        volumes:
        - ./data:/var/elasticsearch
        environment:
            discovery.type: "single-node"
        command: bash -c "elasticsearch-plugin list | grep analysis-icu || elasticsearch-plugin install -b analysis-icu && elasticsearch-plugin list | grep analysis-phonetic || elasticsearch-plugin install -b analysis-phonetic && docker-entrypoint.sh"
        ports:
        - "19201:9200"

The elasticsearch-plugin list | grep analysis-icu || elasticsearch-plugin install -b analysis-icu part will install the analysis-icu plugin if not installed. And we end with the default entrypoint docker-entrypoint.sh.