Remove agent.hostname field from libbeat (#18328)

agent.hostname is not part of ECS so this removes the field. Instead the
agent.name field can be used for this purpose and it it part of ECS.
This adds an alias pointing from agent.hostname to agent.name.

Closes #16377

Author: andrewkroh

CHANGELOG.next.asciidoc

@@ -15,6 +15,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Change aws_elb autodiscover provider field name from elb_listener.* to aws.elb.*. {issue}16219[16219] {pull}16402{16402}
 - Remove `AddDockerMetadata` and `AddKubernetesMetadata` processors from the `script` processor. They can still be used as normal processors in the configuration. {issue}16349[16349] {pull}16514[16514]
 - Introduce APM libbeat instrumentation, active when running the beat with ELASTIC_APM_ACTIVE=true. {pull}17938[17938]
+- Remove the non-ECS `agent.hostname` field. Use the `agent.name` or `agent.id` fields for an identifier. {issue}16377[16377] {pull}18328[18328]
 
 *Auditbeat*
 

auditbeat/docs/fields.asciidoc

@@ -2458,10 +2458,12 @@ Contains common beat fields available in all event types.
 *`agent.hostname`*::
 +
 --
-Deprecated - use agent.name or agent.id to identify an agent. Hostname of the agent.
+Deprecated - use agent.name or agent.id to identify an agent.
 
 
-type: keyword
+type: alias
+
+alias to: agent.name
 
 --
 
@@ -2498,7 +2500,7 @@ alias to: host.name
 --
 type: alias
 
-alias to: agent.hostname
+alias to: agent.name
 
 --
 

auditbeat/include/fields.go

@@ -164,7 +164,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname", 
+                    "agent.name", 
                     "process.args", 
                     "auditd.summary.actor.primary", 
                     "auditd.summary.actor.secondary", 

auditbeat/module/auditd/_meta/kibana/7/dashboard/auditbeat-kernel-executions.json

@@ -146,7 +146,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname", 
+                    "agent.name", 
                     "auditd.summary.actor.primary", 
                     "auditd.summary.actor.secondary", 
                     "event.action", 

auditbeat/module/auditd/_meta/kibana/7/dashboard/auditbeat-kernel-overview.json

@@ -451,7 +451,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname", 
+                    "agent.name", 
                     "auditd.summary.how", 
                     "auditd.summary.object.primary", 
                     "auditd.summary.object.secondary", 
@@ -566,7 +566,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname", 
+                    "agent.name", 
                     "auditd.summary.how", 
                     "auditd.summary.object.primary", 
                     "auditd.summary.object.secondary", 
@@ -673,7 +673,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname", 
+                    "agent.name", 
                     "auditd.summary.how", 
                     "auditd.summary.object.primary", 
                     "auditd.summary.object.secondary", 

auditbeat/module/auditd/_meta/kibana/7/dashboard/auditbeat-kernel-sockets.json

@@ -3113,10 +3113,12 @@ Contains common beat fields available in all event types.
 *`agent.hostname`*::
 +
 --
-Deprecated - use agent.name or agent.id to identify an agent. Hostname of the agent.
+Deprecated - use agent.name or agent.id to identify an agent.
 
 
-type: keyword
+type: alias
+
+alias to: agent.name
 
 --
 
@@ -3153,7 +3155,7 @@ alias to: host.name
 --
 type: alias
 
-alias to: agent.hostname
+alias to: agent.name
 
 --
 

filebeat/docs/fields.asciidoc

@@ -113,7 +113,7 @@
                             "id": "1", 
                             "params": {
                                 "customLabel": "Hosts", 
-                                "field": "agent.hostname"
+                                "field": "agent.name"
                             }, 
                             "schema": "metric", 
                             "type": "cardinality"
@@ -185,7 +185,7 @@
                 "columns": [
                     "osquery.result.name", 
                     "osquery.result.columns.path", 
-                    "agent.hostname"
+                    "agent.name"
                 ], 
                 "description": "", 
                 "hits": 0, 

filebeat/include/fields.go

@@ -269,7 +269,7 @@
                             "id": "1",
                             "params": {
                                 "customLabel": "Hosts Reporting",
-                                "field": "agent.hostname"
+                                "field": "agent.name"
                             },
                             "schema": "metric",
                             "type": "cardinality"
@@ -373,7 +373,7 @@
         {
             "attributes": {
                 "columns": [
-                    "agent.hostname",
+                    "agent.name",
                     "process.executable",
                     "user.name",
                     "certificate.common_name"