docs: Sync Libbeat documentation (#5185)

docs/copied-from-beats/docs/command-reference.asciidoc

@@ -704,12 +704,10 @@ the end of the file is reached. By default harvesters are closed after
 `close_inactive` is reached.
 endif::[]
 
-ifeval::["{beatname_lc}"=="metricbeat"]
 *`--system.hostfs MOUNT_POINT`*::
 
-Specifies the mount point of the host's filesystem for use in monitoring a host
-from within a container.
-endif::[]
+Specifies the mount point of the host's filesystem for use in monitoring a host.
+
 
 ifeval::["{beatname_lc}"=="packetbeat"]
 *`-t`*::

docs/copied-from-beats/docs/loggingconfig.asciidoc

@@ -156,6 +156,12 @@ To see which selectors are available, run {beatname_uc} in debug mode
 after the log level and is enclosed in brackets.
 =====
 
+To configure multiple selectors, use the following {beats-ref}/config-file-format.html[YAML list syntax]:
+["source","yaml",subs="attributes"]
+----
+logging.selectors: [ harvester, input ]
+----
+
 ifndef::serverless[]
 To override selectors at the command line, use the `-d` global flag (`-d` also
 sets the debug log level). For more information, see <<command-line-options>>.
@@ -164,10 +170,11 @@ endif::serverless[]
 [float]
 ==== `logging.metrics.enabled`
 
-If enabled, {beatname_uc} periodically logs its internal metrics that have
+By default, {beatname_uc} periodically logs its internal metrics that have
 changed in the last period. For each metric that changed, the delta from the
 value at the beginning of the period is logged. Also, the total values for all
-non-zero internal metrics are logged on shutdown. The default is true.
+non-zero internal metrics are logged on shutdown. Set this to false to disable 
+this behavior. The default is true.
 
 Here is an example log line:
 
@@ -249,7 +256,8 @@ When true, logs messages in JSON format. The default is false.
 [float]
 ==== `logging.ecs`
 
-When true, logs messages in Elastic Common Schema (ECS) compliant format.
+When true, logs messages with minimal required Elastic Common Schema (ECS)
+information.
 
 ifndef::serverless[]
 [float]

docs/copied-from-beats/docs/monitoring/monitoring-metricbeat.asciidoc

@@ -83,6 +83,32 @@ For more information, see
 <<configuration-monitor,Monitoring configuration options>>.
 --
 
+. Configure host (optional). +
++
+--
+// tag::set-http-host[]
+If you intend to get metrics using {metricbeat} installed on another server, you need to bind the {beatname_uc} to host's IP:
+
+[source,yaml]
+----------------------------------
+http.host: xxx.xxx.xxx.xxx
+----------------------------------
+// end::set-http-host[]
+--
+
+. Configure cluster uuid (optional). +
++
+--
+// tag::set-cluster-uuid[]
+To see the Beats monitoring section in Kibana if you have a cluster, you need to associate the {beatname_uc} with cluster UUID:
+
+[source,yaml]
+----------------------------------
+monitoring.cluster_uuid: "cluster-uuid"
+----------------------------------
+// end::set-cluster-uuid[]
+--
+
 ifndef::serverless[]
 . Start {beatname_uc}.
 endif::[]

docs/copied-from-beats/docs/shared-docker.asciidoc

@@ -5,13 +5,13 @@ Docker images for {beatname_uc} are available from the Elastic Docker
 registry. The base image is https://hub.docker.com/_/centos/[centos:7].
 
 A list of all published Docker images and tags is available at
-https://www.docker.elastic.co[www.docker.elastic.co]. 
+https://www.docker.elastic.co[www.docker.elastic.co].
 
-These images are free to use under the Elastic license. They contain open source 
-and free commercial features and access to paid commercial features.  
-{kibana-ref}/managing-licenses.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 
+These images are free to use under the Elastic license. They contain open source
+and free commercial features and access to paid commercial features.
+{kibana-ref}/managing-licenses.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.
 
 ==== Pull the image
@@ -34,8 +34,8 @@ docker pull {dockerimage}
 ------------------------------------------------
 
 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]. 
+available under the Apache 2.0 license. To download the images, go to
+https://www.docker.elastic.co[www.docker.elastic.co].
 
 endif::[]
 
@@ -129,7 +129,7 @@ endif::apm-server[]
 ==== Configure {beatname_uc} on Docker
 
 The Docker image provides several methods for configuring {beatname_uc}. The
-conventional approach is to provide a configuration file via a volume mount, but 
+conventional approach is to provide a configuration file via a volume mount, but
 it's also possible to create a custom image with your
 configuration included.
 
@@ -244,6 +244,7 @@ ifeval::["{beatname_lc}"=="apm-server"]
 ["source", "sh", subs="attributes"]
 --------------------------------------------
 docker run -d \
+  -p 8200:8200 \
   --name={beatname_lc} \
   --user={beatname_lc} \
   --volume="$(pwd)/{beatname_lc}.docker.yml:/usr/share/{beatname_lc}/{beatname_lc}.yml:ro" \

docs/copied-from-beats/docs/shared-path-config.asciidoc

@@ -106,3 +106,20 @@ Example:
 ------------------------------------------------------------------------------
 path.logs: /var/log/beats
 ------------------------------------------------------------------------------
+
+[float]
+==== `system.hostfs`
+
+Specifies the mount point of the host's filesystem for use in monitoring a host.
+This can either be set in the config, or with the `--system.hostfs` CLI flag. This is used for cgroup self-monitoring.
+ifeval::["{beatname_lc}"=="metricbeat"]
+This is also used by the system module to read files from `/proc` and `/sys`.
+endif::[]
+
+
+Example:
+
+[source,yaml]
+------------------------------------------------------------------------------
+system.hostfs: /mount/rootfs
+------------------------------------------------------------------------------