[[logstash-modules]]
== Working with Logstash Modules

Logstash modules provide a quick, end-to-end solution for ingesting data and
visualizing it with purpose-built dashboards.

These modules are available:

* <<connecting-to-cloud,Elastic Cloud>>
* <<arcsight-module>>
* <<netflow-module>>
* <<azure-module, Microsoft Azure Module>>

Each module comes pre-packaged with Logstash configurations, Kibana dashboards,
and other meta files that make it easier for you to set up the Elastic Stack for
specific use cases or data sources.

You can think of modules as providing three essential functions that make it
easier for you to get started. When you run a module, it will:

. Create the Elasticsearch index.

. Set up the Kibana dashboards, including the index pattern, searches, and
visualizations required to visualize your data in Kibana.

. Run the Logstash pipeline with the configurations required to read and parse
the data.

image::static/images/logstash-module-overview.png[Logstash modules overview]

[float]
[[running-logstash-modules]]
=== Running modules

To run a module and set up dashboards, you specify the following options:

[source,shell]
----
bin/logstash --modules MODULE_NAME --setup [-M "CONFIG_SETTING=VALUE"]
----


//TODO: For 6.0, show how to run multiple modules

Where:

* `--modules` runs the Logstash module specified by `MODULE_NAME`.

* `-M "CONFIG_SETTING=VALUE"` is optional and overrides the specified
configuration setting. You can specify multiple overrides. Each override must
start with `-M`. See <<overriding-logstash-module-settings>> for more info.

* `--setup` creates an index pattern in Elasticsearch and imports Kibana
dashboards and visualizations. Running `--setup` is a one-time setup step. Omit
this option for subsequent runs of the module to avoid overwriting existing
Kibana dashboards.

For example, the following command runs the Netflow module with the default
settings, and sets up the netflow index pattern and dashboards:

[source,shell]
----
bin/logstash --modules netflow --setup 
----

The following command runs the Netflow module and overrides the Elasticsearch
`host` setting. Here it's assumed that you've already run the setup step.

[source,shell]
----
bin/logstash --modules netflow -M "netflow.var.elasticsearch.host=es.mycloud.com"
----


[float]
[[configuring-logstash-modules]]
=== Configuring modules

To configure a module, you can either
<<setting-logstash-module-config,specify configuration settings>> in the
`logstash.yml` <<logstash-settings-file,settings file>>, or use command-line overrides to
<<overriding-logstash-module-settings,specify settings at the command line>>.

[float]
[[setting-logstash-module-config]]
==== Specify module settings in `logstash.yml`

To specify module settings in the `logstash.yml`
<<logstash-settings-file,settings file>> file, you add a module definition to
the modules array. Each module definition begins with a dash (-) and is followed
by `name: module_name` then a series of name/value pairs that specify module
settings. For example:

[source,shell]
----
modules:
- name: netflow
  var.elasticsearch.hosts: "es.mycloud.com"
  var.elasticsearch.username: "foo"
  var.elasticsearch.password: "password"
  var.kibana.host: "kb.mycloud.com"
  var.kibana.username: "foo"
  var.kibana.password: "password"
  var.input.tcp.port: 5606
----

For a list of available module settings, see the documentation for the module.

[float]
[[overriding-logstash-module-settings]]
==== Specify module settings at the command line

You can override module settings by specifying one or more configuration
overrides when you start Logstash. To specify an override, you use the `-M`
command line option:

[source,shell]
----
-M MODULE_NAME.var.PLUGINTYPE1.PLUGINNAME1.KEY1=VALUE
----

Notice that the fully-qualified setting name includes the module name.

You can specify multiple overrides. Each override must start with `-M`. 

The following command runs the Netflow module and overrides both the
Elasticsearch `host` setting and the `udp.port` setting:

[source,shell]
----
bin/logstash --modules netflow -M "netflow.var.input.udp.port=3555" -M "netflow.var.elasticsearch.hosts=my-es-cloud"
----

Any settings defined in the command line are ephemeral and will not persist across
subsequent runs of Logstash. If you want to persist a configuration, you need to
set it in the `logstash.yml` <<logstash-settings-file,settings file>>.

Settings that you specify at the command line are merged with any settings 
specified in the `logstash.yml` file. If an option is set in both
places, the value specified at the command line takes precedence. 

[[connecting-to-cloud]]
=== Using Elastic Cloud

Logstash comes with two settings that simplify using modules with https://cloud.elastic.co/[Elastic Cloud].
The Elasticsearch and Kibana hostnames in Elastic Cloud may be hard to set
in the Logstash config or on the commandline, so a Cloud ID can be used instead.

NOTE: Cloud ID applies only when a Logstash module is enabled, otherwise
specifying Cloud ID has no effect. Cloud ID applies to data that gets sent via
the module, to runtime metrics sent via {xpack} monitoring, and to the endpoint
used by {xpack} central management features of Logstash, unless explicit
overrides to {xpack} settings are specified in `logstash.yml`.

==== Cloud ID

The Cloud ID, which can be found in the Elastic Cloud web console, is used by
Logstash to build the Elasticsearch and Kibana hosts settings.
It is a base64 encoded text value of about 120 characters made up of upper and
lower case letters and numbers.
If you have several Cloud IDs, you can add a label, which is ignored
internally, to help you tell them apart. To add a label you should prefix your
Cloud ID with a label and a `:` separator in this format "<label>:<cloud-id>"

`cloud.id` will overwrite these settings:
----
var.elasticsearch.hosts
var.kibana.host
----

==== Cloud Auth
This is optional. Construct this value by following this format "<username>:<password>".
Use your Cloud username for the first part. Use your Cloud password for the second part,
which is given once in the Cloud UI when you create a cluster.
As your Cloud password is changeable, if you change it in the Cloud UI remember to change it here too.

`cloud.auth` when specified will overwrite these settings:
----
var.elasticsearch.username
var.elasticsearch.password
var.kibana.username
var.kibana.password
----

Example:

These settings can be specified in the `logstash.yml` <<logstash-settings-file,settings file>>.
They should be added separately from any module configuration settings you may have added before.

["source","yaml",subs="attributes"]
----
# example with a label
cloud.id: "staging:dXMtZWFzdC0xLmF3cy5mb3VuZC5pbyRub3RhcmVhbCRpZGVudGlmaWVy"
cloud.auth: "elastic:{pwd}"
----

["source","yaml",subs="attributes"]
----
# example without a label
cloud.id: "dXMtZWFzdC0xLmF3cy5mb3VuZC5pbyRub3RhcmVhbCRpZGVudGlmaWVy"
cloud.auth: "elastic:{pwd}"
----

These settings can be also specified at the command line, like this:

["source","sh",subs="attributes,callouts"]
----
bin/logstash --modules netflow -M "netflow.var.input.udp.port=3555" --cloud.id <cloud-id> --cloud.auth <cloud.auth>
----


