configuring-tls-docker.asciidoc

Encrypting Communications in an {es} Docker Container

Starting with version 6.0.0, {security} (Gold, Platinum or Enterprise subscriptions) requires SSL/TLS encryption for the transport networking layer.

This section demonstrates an easy path to get started with SSL/TLS for both HTTPS and transport using the {es} Docker image. The example uses Docker Compose to manage the containers.

For further details, please refer to {xpack-ref}/encrypting-communications.html[Encrypting Communications] and available subscriptions.

Prepare the environment

Install {es} with Docker.

Inside a new, empty directory, create the following four files:

instances.yml:

instances:
  - name: es01
    dns:
      - es01 (1)
      - localhost
    ip:
      - 127.0.0.1

  - name: es02
    dns:
      - es02
      - localhost
    ip:
      - 127.0.0.1

1. Allow use of embedded Docker DNS server names.

.env:

CERTS_DIR=/usr/share/elasticsearch/config/certificates (1)
ELASTIC_PASSWORD=PleaseChangeMe (2)

1. The path, inside the Docker image, where certificates are expected to be found.

2. Initial password for the elastic user.

create-certs.yml:

version: '2.2'

services:
  create_certs:
    container_name: create_certs
    image: {docker-image}
    command: >
      bash -c '
        if [[ ! -d config/certificates/certs ]]; then
          mkdir config/certificates/certs;
        fi;
        if [[ ! -f /local/certs/bundle.zip ]]; then
          bin/elasticsearch-certgen --silent --in config/certificates/instances.yml --out config/certificates/certs/bundle.zip;
          unzip config/certificates/certs/bundle.zip -d config/certificates/certs; <1>
        fi;
        chgrp -R 0 config/certificates/certs
      '
    user: $\{UID:-1000\}
    working_dir: /usr/share/elasticsearch
    volumes: ['.:/usr/share/elasticsearch/config/certificates']

1. The new node certificates and CA certificate+key are placed under the local directory certs.

docker-compose.yml:

version: '2.2'

services:
  es01:
    container_name: es01
    image: {docker-image}
    environment:
      - node.name=es01
      - discovery.zen.minimum_master_nodes=2
      - ELASTIC_PASSWORD=$ELASTIC_PASSWORD <1>
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
      - xpack.license.self_generated.type=trial <2>
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.verification_mode=certificate <3>
      - xpack.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.ssl.certificate=$CERTS_DIR/es01/es01.crt
      - xpack.ssl.key=$CERTS_DIR/es01/es01.key
    volumes: ['esdata_01:/usr/share/elasticsearch/data', './certs:$CERTS_DIR']
    ports:
      - 9200:9200
    healthcheck:
      test: curl --cacert $CERTS_DIR/ca/ca.crt -s https://localhost:9200 >/dev/null; if [[ $$? == 52 ]]; then echo 0; else echo 1; fi
      interval: 30s
      timeout: 10s
      retries: 5

  es02:
    container_name: es02
    image: {docker-image}
    environment:
      - node.name=es02
      - discovery.zen.minimum_master_nodes=2
      - ELASTIC_PASSWORD=$ELASTIC_PASSWORD
      - discovery.zen.ping.unicast.hosts=es01
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
      - xpack.license.self_generated.type=trial
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.verification_mode=certificate
      - xpack.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.ssl.certificate=$CERTS_DIR/es02/es02.crt
      - xpack.ssl.key=$CERTS_DIR/es02/es02.key
    volumes: ['esdata_02:/usr/share/elasticsearch/data', './certs:$CERTS_DIR']

  wait_until_ready:
    image: {docker-image}
    command: /usr/bin/true
    depends_on: {"es01": {"condition": "service_healthy"}}

volumes: {"esdata_01": {"driver": "local"}, "esdata_02": {"driver": "local"}}

1. Bootstrap elastic with the password defined in .env. See {stack-ov}/built-in-users.html#bootstrap-elastic-passwords[the Elastic Bootstrap Password].

2. Automatically generate and apply a trial subscription, in order to enable {security}.

3. Disable verification of authenticity for inter-node communication. Allows creating self-signed certificates without having to pin specific internal IP addresses.

Run the example

1. Generate the certificates (only needed once):

   docker-compose -f create-certs.yml up

2. Start two {es} nodes configured for SSL/TLS:

   docker-compose up -d

3. Access the {es} API over SSL/TLS using the bootstrapped password:

   curl --cacert certs/ca/ca.crt -u elastic:PleaseChangeMe https://localhost:9200

4. The elasticsearch-setup-passwords tool can also be used to generate random passwords for all users:

   Warning

   Windows users not running PowerShell will need to remove \ and join lines in the snippet below.

   docker exec es01 /bin/bash -c "bin/elasticsearch-setup-passwords \
   auto --batch \
   -Expack.ssl.certificate=certificates/es01/es01.crt \
   -Expack.ssl.certificate_authorities=certificates/ca/ca.crt \
   -Expack.ssl.key=certificates/es01/es01.key \
   --url https://localhost:9200"