[Docs] Add info about accessing logs in serverless environments (#9241)

libbeat/docs/loggingconfig.asciidoc

@@ -14,31 +14,54 @@
 == Configure logging
 
 The `logging` section of the +{beatname_lc}.yml+ config file contains options
-for configuring the logging output. The logging system can write logs to
-the syslog or rotate log files. If logging is not explicitly configured the file
-output is used.
+for configuring the logging output.
+ifndef::serverless[]
+The logging system can write logs to the syslog or rotate log files. If logging
+is not explicitly configured the file output is used.
 
 ["source","yaml",subs="attributes"]
---------------------------------------------------------------------------------
+----
 logging.level: info
 logging.to_files: true
 logging.files:
   path: /var/log/{beatname_lc}
   name: {beatname_lc}
   keepfiles: 7
   permissions: 0644
---------------------------------------------------------------------------------
+----
 
 TIP: In addition to setting logging options in the config file, you can modify
 the logging output configuration from the command line. See
 <<command-line-options>>.
+endif::serverless[]
+
+ifdef::serverless[]
+For example, the following options configure {beatname_uc} to log all the debug
+messages related to event publishing:
+
+["source","yaml",subs="attributes"]
+----
+logging.level: debug
+logging.selectors: ["publish"]
+----
+
+The logs generated by {beatname_uc} are written to the CloudWatch log group for
+the function running on Amazon Web Services (AWS). To view the logs, go to the
+the monitoring area of the AWS Lambda console and view the CloudWatch log group
+for the function.
+
+// TODO: When we add support for other cloud providers, we will need to modify
+// this statement and possibly have a different attribute for each provider to
+// show the correct text.
+endif::serverless[]
 
 [float]
 === Configuration options
 
 You can specify the following options in the `logging` section of the
 +{beatname_lc}.yml+ config file:
 
+ifndef::serverless[]
 [float]
 ==== `logging.to_syslog`
 
@@ -60,6 +83,7 @@ rotated when the log file size limit is reached.
 NOTE: {beatname_uc} only creates a log file if there is logging output. For
 example, if you set the log <<level,`level`>> to `error` and there are no
 errors, there will be no log file in the directory specified for logs.
+endif::serverless[]
 
 [float]
 [[level]]
@@ -88,9 +112,11 @@ published. Also logs any warnings, errors, or critical errors.
 
 The list of debugging-only selector tags used by different {beatname_uc} components.
 Use `*` to enable debug output for all components. For example add `publish` to display
-all the debug messages related to event publishing. When starting {beatname_lc},
-selectors can be overwritten using the `-d` command line option (`-d` also sets
-the debug log level).
+all the debug messages related to event publishing.
+ifndef::serverless[]
+When starting {beatname_lc}, selectors can be overwritten using the `-d` command
+line option (`-d` also sets the debug log level).
+endif::serverless[]
 
 [float]
 ==== `logging.metrics.enabled`
@@ -110,12 +136,12 @@ Here is an example log line:
 Note that we currently offer no backwards compatible guarantees for the internal
 metrics and for this reason they are also not documented.
 
-
 [float]
 ==== `logging.metrics.period`
 
 The period after which to log the internal metrics. The default is 30s.
 
+ifndef::serverless[]
 [float]
 ==== `logging.files.path`
 
@@ -163,12 +189,14 @@ Intervals must be at least 1s. Values of 1m, 1h, 24h, 7*24h, 30*24h, and 365*24h
 are boundary-aligned with minutes, hours, days, weeks, months, and years as
 reported by the local system clock. All other intervals are calculated from the
 unix epoch. Defaults to disabled.
+endif::serverless[]
 
 [float]
 ==== `logging.json`
 
 When true, logs messages in JSON format. The default is false.
 
+ifndef::serverless[]
 [float]
 ==== `logging.files.redirect_stderr` experimental[]
 
@@ -178,6 +206,7 @@ will also be logged to the log file. This can be helpful in situations were
 Go's runtime but diagnostic information is not present in the log file.
 This feature is only available when logging to files (`logging.to_files` is true).
 Disabled by default.
+endif::serverless[]
 
 [float]
 === Logging format