David Turner 1a23417aeb
[Zen2] Update documentation for Zen2 (#34714)
This commit overhauls the documentation of discovery and cluster coordination,
removing mention of the Zen Discovery module and replacing it with docs for the
new cluster coordination mechanism introduced in 7.0.

Relates #32006
2018-12-20 13:02:44 +00:00

395 lines
14 KiB
Plaintext

[[docker]]
=== Install {es} with Docker
{es} is also available as Docker images.
The images use https://hub.docker.com/_/centos/[centos:7] as the base image.
A list of all published Docker images and tags is available at
https://www.docker.elastic.co[www.docker.elastic.co]. The source code is in
https://github.com/elastic/elasticsearch-docker/tree/{branch}[GitHub].
These images are free to use under the Elastic license. They contain open source
and free commercial features and access to paid commercial features.
{xpack-ref}/license-management.html[Start a 30-day trial] to try out all of the
paid commercial features. See the
https://www.elastic.co/subscriptions[Subscriptions] page for information about
Elastic license levels.
==== Pulling the image
Obtaining {es} for Docker is as simple as issuing a +docker pull+ command
against the Elastic Docker registry.
ifeval::["{release-state}"=="unreleased"]
WARNING: Version {version} of {es} has not yet been released, so no
Docker image is currently available for this version.
endif::[]
ifeval::["{release-state}"!="unreleased"]
["source","sh",subs="attributes"]
--------------------------------------------
docker pull {docker-repo}:{version}
--------------------------------------------
Alternatively, you can download other Docker images that contain only features
available under the Apache 2.0 license. To download the images, go to
https://www.docker.elastic.co[www.docker.elastic.co].
endif::[]
[[docker-cli-run]]
==== Running {es} from the command line
[[docker-cli-run-dev-mode]]
===== Development mode
ifeval::["{release-state}"=="unreleased"]
WARNING: Version {version} of the {es} Docker image has not yet been released.
endif::[]
ifeval::["{release-state}"!="unreleased"]
{es} can be quickly started for development or testing use with the following command:
["source","sh",subs="attributes"]
--------------------------------------------
docker run -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" {docker-image}
--------------------------------------------
endif::[]
[[docker-cli-run-prod-mode]]
===== Production mode
[[docker-prod-prerequisites]]
[IMPORTANT]
=========================
The `vm.max_map_count` kernel setting needs to be set to at least `262144` for
production use. Depending on your platform:
* Linux
+
--
The `vm.max_map_count` setting should be set permanently in `/etc/sysctl.conf`:
[source,sh]
--------------------------------------------
$ grep vm.max_map_count /etc/sysctl.conf
vm.max_map_count=262144
----------------------------------
To apply the setting on a live system type: `sysctl -w vm.max_map_count=262144`
--
* macOS with https://docs.docker.com/engine/installation/mac/#/docker-for-mac[Docker for Mac]
+
--
The `vm.max_map_count` setting must be set within the xhyve virtual machine:
["source","sh"]
--------------------------------------------
$ screen ~/Library/Containers/com.docker.docker/Data/vms/0/tty
--------------------------------------------
Just press enter and configure the `sysctl` setting as you would for Linux:
["source","sh"]
--------------------------------------------
sysctl -w vm.max_map_count=262144
--------------------------------------------
--
* Windows and macOS with https://www.docker.com/products/docker-toolbox[Docker Toolbox]
+
--
The `vm.max_map_count` setting must be set via docker-machine:
["source","txt"]
--------------------------------------------
docker-machine ssh
sudo sysctl -w vm.max_map_count=262144
--------------------------------------------
--
=========================
The following example brings up a cluster comprising two {es} nodes.
To bring up the cluster, use the
<<docker-prod-cluster-composefile,`docker-compose.yml`>> and just type:
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","sh"]
--------------------------------------------
docker-compose up
--------------------------------------------
endif::[]
[NOTE]
`docker-compose` is not pre-installed with Docker on Linux.
Instructions for installing it can be found on the
https://docs.docker.com/compose/install/#install-using-pip[Docker Compose webpage].
The node `es01` listens on `localhost:9200` while `es02`
talks to `es01` over a Docker network.
This example also uses
https://docs.docker.com/engine/tutorials/dockervolumes[Docker named volumes],
called `esdata01` and `esdata02` which will be created if not already present.
[[docker-prod-cluster-composefile]]
`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:
image: {docker-image}
container_name: es01
environment:
- node.name=es01
- cluster.initial_master_nodes=es01,es02
- cluster.name=docker-cluster
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
ulimits:
memlock:
soft: -1
hard: -1
volumes:
- esdata01:/usr/share/elasticsearch/data
ports:
- 9200:9200
networks:
- esnet
es02:
image: {docker-image}
container_name: es02
environment:
- node.name=es02
- discovery.zen.ping.unicast.hosts=es01
- cluster.initial_master_nodes=es01,es02
- cluster.name=docker-cluster
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
ulimits:
memlock:
soft: -1
hard: -1
volumes:
- esdata02:/usr/share/elasticsearch/data
networks:
- esnet
volumes:
esdata01:
driver: local
esdata02:
driver: local
networks:
esnet:
--------------------------------------------
endif::[]
To stop the cluster, type `docker-compose down`. Data volumes will persist,
so it's possible to start the cluster again with the same data using
`docker-compose up`.
To destroy the cluster **and the data volumes**, just type
`docker-compose down -v`.
===== Inspect status of cluster:
["source","txt"]
--------------------------------------------
curl http://127.0.0.1:9200/_cat/health
1472225929 15:38:49 docker-cluster green 2 2 4 2 0 0 0 0 - 100.0%
--------------------------------------------
// NOTCONSOLE
Log messages go to the console and are handled by the configured Docker logging
driver. By default you can access logs with `docker logs`.
[[docker-configuration-methods]]
==== Configuring {es} with Docker
{es} loads its configuration from files under `/usr/share/elasticsearch/config/`.
These configuration files are documented in <<settings>> and <<jvm-options>>.
The image offers several methods for configuring {es} settings with the
conventional approach being to provide customized files, that is to say
`elasticsearch.yml`, but it's also possible to use environment variables to set
options:
===== A. Present the parameters via Docker environment variables
For example, to define the cluster name with `docker run` you can pass
`-e "cluster.name=mynewclustername"`. Double quotes are required.
===== B. Bind-mounted configuration
Create your custom config file and mount this over the image's corresponding file.
For example, bind-mounting a `custom_elasticsearch.yml` with `docker run` can be
accomplished with the parameter:
["source","sh"]
--------------------------------------------
-v full_path_to/custom_elasticsearch.yml:/usr/share/elasticsearch/config/elasticsearch.yml
--------------------------------------------
IMPORTANT: The container **runs {es} as user `elasticsearch` using
uid:gid `1000:1000`**. Bind mounted host directories and files, such as
`custom_elasticsearch.yml` above, **need to be accessible by this user**. For the <<path-settings, data and log dirs>>,
such as `/usr/share/elasticsearch/data`, write access is required as well.
Also see note 1 below.
===== C. Customized image
In some environments, it may make more sense to prepare a custom image containing
your configuration. A `Dockerfile` to achieve this may be as simple as:
["source","sh",subs="attributes"]
--------------------------------------------
FROM docker.elastic.co/elasticsearch/elasticsearch:{version}
COPY --chown=elasticsearch:elasticsearch elasticsearch.yml /usr/share/elasticsearch/config/
--------------------------------------------
You could then build and try the image with something like:
["source","sh"]
--------------------------------------------
docker build --tag=elasticsearch-custom .
docker run -ti -v /usr/share/elasticsearch/data elasticsearch-custom
--------------------------------------------
Some plugins require additional security permissions. You have to explicitly accept
them either by attaching a `tty` when you run the Docker image and accepting yes at
the prompts, or inspecting the security permissions separately and if you are
comfortable with them adding the `--batch` flag to the plugin install command.
See {plugins}/_other_command_line_parameters.html[Plugin Management documentation]
for more details.
===== D. Override the image's default https://docs.docker.com/engine/reference/run/#cmd-default-command-or-options[CMD]
Options can be passed as command-line options to the {es} process by
overriding the default command for the image. For example:
["source","sh"]
--------------------------------------------
docker run <various parameters> bin/elasticsearch -Ecluster.name=mynewclustername
--------------------------------------------
[[next-getting-started-tls-docker]]
==== Configuring SSL/TLS with the {es} Docker image
See <<configuring-tls-docker>>.
==== Notes for production use and defaults
We have collected a number of best practices for production use.
Any Docker parameters mentioned below assume the use of `docker run`.
. By default, {es} runs inside the container as user `elasticsearch` using
uid:gid `1000:1000`.
+
--
CAUTION: One exception is https://docs.openshift.com/container-platform/3.6/creating_images/guidelines.html#openshift-specific-guidelines[Openshift],
which runs containers using an arbitrarily assigned user ID. Openshift will
present persistent volumes with the gid set to `0` which will work without any
adjustments.
If you are bind-mounting a local directory or file, ensure it is readable by
this user, while the <<path-settings,data and log dirs>> additionally require
write access. A good strategy is to grant group access to gid `1000` or `0` for
the local directory. As an example, to prepare a local directory for storing
data through a bind-mount:
mkdir esdatadir
chmod g+rwx esdatadir
chgrp 1000 esdatadir
As a last resort, you can also force the container to mutate the ownership of
any bind-mounts used for the <<path-settings,data and log dirs>> through the
environment variable `TAKE_FILE_OWNERSHIP`. Inn this case, they will be owned by
uid:gid `1000:0` providing read/write access to the {es} process as required.
--
. It is important to ensure increased ulimits for
<<setting-system-settings,nofile>> and <<max-number-threads-check,nproc>> are
available for the {es} containers. Verify the https://github.com/moby/moby/tree/ea4d1243953e6b652082305a9c3cda8656edab26/contrib/init[init system]
for the Docker daemon is already setting those to acceptable values and, if
needed, adjust them in the Daemon, or override them per container, for example
using `docker run`:
+
--
--ulimit nofile=65536:65536
NOTE: One way of checking the Docker daemon defaults for the aforementioned
ulimits is by running:
docker run --rm centos:7 /bin/bash -c 'ulimit -Hn && ulimit -Sn && ulimit -Hu && ulimit -Su'
--
. Swapping needs to be disabled for performance and node stability. This can be
achieved through any of the methods mentioned in the
<<setup-configuration-memory,{es} docs>>. If you opt for the
`bootstrap.memory_lock: true` approach, apart from defining it through any of
the <<docker-configuration-methods,configuration methods>>, you will
additionally need the `memlock: true` ulimit, either defined in the
https://docs.docker.com/engine/reference/commandline/dockerd/#default-ulimits[Docker Daemon]
or specifically set for the container. This is demonstrated above in the
<<docker-prod-cluster-composefile,docker-compose.yml>>. If using `docker run`:
+
--
-e "bootstrap.memory_lock=true" --ulimit memlock=-1:-1
--
. The image https://docs.docker.com/engine/reference/builder/#/expose[exposes]
TCP ports 9200 and 9300. For clusters it is recommended to randomize the
published ports with `--publish-all`, unless you are pinning one container per host.
. Use the `ES_JAVA_OPTS` environment variable to set heap size. For example, to
use 16GB, use `-e ES_JAVA_OPTS="-Xms16g -Xmx16g"` with `docker run`.
. Pin your deployments to a specific version of the {es} Docker image, for
example +docker.elastic.co/elasticsearch/elasticsearch:{version}+.
. Always use a volume bound on `/usr/share/elasticsearch/data`, as shown in the
<<docker-cli-run-prod-mode,production example>>, for the following reasons:
.. The data of your {es} node won't be lost if the container is killed
.. {es} is I/O sensitive and the Docker storage driver is not ideal for fast I/O
.. It allows the use of advanced
https://docs.docker.com/engine/extend/plugins/#volume-plugins[Docker volume plugins]
. If you are using the devicemapper storage driver, make sure you are not using
the default `loop-lvm` mode. Configure docker-engine to use
https://docs.docker.com/engine/userguide/storagedriver/device-mapper-driver/#configure-docker-with-devicemapper[direct-lvm]
instead.
. Consider centralizing your logs by using a different
https://docs.docker.com/engine/admin/logging/overview/[logging driver]. Also
note that the default json-file logging driver is not ideally suited for
production use.
include::next-steps.asciidoc[]