[role="xpack"]
[[configuring-tls-docker]]
=== Encrypting communications in an {es} Docker Container

Unless you are using a trial license, {stack} {security-features} require
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, see
<<encrypting-communications>> and
https://www.elastic.co/subscriptions[available subscriptions].

[float]
==== Prepare the environment

<<docker,Install {es} with Docker>>.

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

`instances.yml`:
["source","yaml"]
----
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`:
[source,yaml]
----
COMPOSE_PROJECT_NAME=es <1>
CERTS_DIR=/usr/share/elasticsearch/config/certificates <2>
ELASTIC_PASSWORD=PleaseChangeMe <3>
----
<1> Use an `es_` prefix for all volumes and networks created by docker-compose.
<2> The path, inside the Docker image, where certificates are expected to be found.
<3> Initial password for the `elastic` user.

[[getting-starter-tls-create-certs-composefile]]
`create-certs.yml`:
ifeval::["{release-state}"=="unreleased"]

WARNING: Version {version} of {es} has not yet been released, so a
`create-certs.yml` is not available for this version.

endif::[]

ifeval::["{release-state}"!="unreleased"]
["source","yaml",subs="attributes"]
----
version: '2.2'

services:
  create_certs:
    container_name: create_certs
    image: {docker-image}
    command: >
      bash -c '
        yum install -y -q -e 0 unzip;
        if [[ ! -f /certs/bundle.zip ]]; then
          bin/elasticsearch-certutil cert --silent --pem --in config/certificates/instances.yml -out /certs/bundle.zip;
          unzip /certs/bundle.zip -d /certs; <1>
        fi;
        chown -R 1000:0 /certs
      '
    user: "0"
    working_dir: /usr/share/elasticsearch
    volumes: ['certs:/certs', '.:/usr/share/elasticsearch/config/certificates']

volumes: {"certs"}
----

<1> The new node certificates and CA certificate+key are placed in a docker volume `es_certs`.
endif::[]

[[getting-starter-tls-create-docker-compose]]
`docker-compose.yml`:
ifeval::["{release-state}"=="unreleased"]

WARNING: Version {version} of {es} has not yet been released, so a
`docker-compose.yml` is not available for this version.

endif::[]

ifeval::["{release-state}"!="unreleased"]
["source","yaml",subs="attributes"]
----
version: '2.2'

services:
  es01:
    container_name: es01
    image: {docker-image}
    environment:
      - node.name=es01
      - discovery.seed_hosts=es01,es02
      - cluster.initial_master_nodes=es01,es02
      - ELASTIC_PASSWORD=$ELASTIC_PASSWORD <1>
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
      - xpack.license.self_generated.type=trial <2>
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.http.ssl.key=$CERTS_DIR/es01/es01.key
      - xpack.security.http.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.security.http.ssl.certificate=$CERTS_DIR/es01/es01.crt
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.verification_mode=certificate <3>
      - xpack.security.transport.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.security.transport.ssl.certificate=$CERTS_DIR/es01/es01.crt
      - xpack.security.transport.ssl.key=$CERTS_DIR/es01/es01.key
    volumes: ['data01:/usr/share/elasticsearch/data', 'certs:$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.seed_hosts=es01,es02
      - cluster.initial_master_nodes=es01,es02
      - ELASTIC_PASSWORD=$ELASTIC_PASSWORD
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
      - xpack.license.self_generated.type=trial
      - xpack.security.enabled=true
      - xpack.security.http.ssl.enabled=true
      - xpack.security.http.ssl.key=$CERTS_DIR/es02/es02.key
      - xpack.security.http.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.security.http.ssl.certificate=$CERTS_DIR/es02/es02.crt
      - xpack.security.transport.ssl.enabled=true
      - xpack.security.transport.ssl.verification_mode=certificate <3>
      - xpack.security.transport.ssl.certificate_authorities=$CERTS_DIR/ca/ca.crt
      - xpack.security.transport.ssl.certificate=$CERTS_DIR/es02/es02.crt
      - xpack.security.transport.ssl.key=$CERTS_DIR/es02/es02.key
    volumes: ['data02:/usr/share/elasticsearch/data', 'certs:$CERTS_DIR']

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

volumes: {"data01", "data02", "certs"}
----

<1> Bootstrap `elastic` with the password defined in `.env`. See
<<bootstrap-elastic-passwords>>.
<2> Automatically generate and apply a trial subscription, in order to enable
{security-features}.
<3> Disable verification of authenticity for inter-node communication. Allows
creating self-signed certificates without having to pin specific internal IP addresses.
endif::[]

[float]
==== Run the example
. Generate the certificates (only needed once):
+
--
["source","sh"]
----
docker-compose -f create-certs.yml run --rm create_certs
----
--
. Start two {es} nodes configured for SSL/TLS:
+
--
["source","sh"]
----
docker-compose up -d
----
--
. Access the {es} API over SSL/TLS using the bootstrapped password:
+
--
["source","sh",subs="attributes"]
----
docker run --rm -v es_certs:/certs --network=es_default {docker-image} curl --cacert /certs/ca/ca.crt -u elastic:PleaseChangeMe https://es01:9200
----
// NOTCONSOLE
--
. 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.
["source","sh"]
----
docker exec es01 /bin/bash -c "bin/elasticsearch-setup-passwords \
auto --batch \
-Expack.security.http.ssl.certificate=certificates/es01/es01.crt \
-Expack.security.http.ssl.certificate_authorities=certificates/ca/ca.crt \
-Expack.security.http.ssl.key=certificates/es01/es01.key \
--url https://localhost:9200"
----
--

[float]
==== Tear everything down
To remove all the Docker resources created by the example, issue:
--
["source","sh"]
----
docker-compose down -v
----
--
