Feature: Add support for logstash output

Author: noqqe

README.md

@@ -17,7 +17,9 @@ You can install libc6-compat using ``apk add --no-cache libc6-compat``.
 
 ## Simple example ##
 
-For detailed example please refer to this [blog post](https://medium.com/@pascal-euhus/terraform-functionbeat-e481554d729e)
+For detailed example please refer to this [blog post](https://medium.com/@pascal-euhus/terraform-functionbeat-e481554d729e) using Elasticsearch output
+Please note that output to Logstash is also possible, but in this example we
+use Elasticsearch.
 
 ````terraform
 resource "aws_security_group" "functionbeat_securitygroup" {
@@ -59,7 +61,7 @@ module "functionbeat" {
 
 ## Advanced example ##
 
-Head over to `example/main.tf` to get an more advanced example.
+Head over to `example/elasticsearch.tf` to get an more advanced example.
 
 ## Usage ##
 
@@ -94,10 +96,10 @@ You configure your lambda here.
     }
     # You can put any HCL-Map with valid Functionbeat config for Elasticsearch Output 
     output_elasticsearch = {
-      hosts : ["https://your-endpoint:443"]
-      protocol : "https"
-      username : "elastic"
-      password : "mysupersecret"
+      hosts = ["https://your-endpoint:443"]
+      protocol = "https"
+      username = "elastic"
+      password = "mysupersecret"
     }
   }
 ````

examples/main.tf renamed to examples/elasticsearch.tf

@@ -53,11 +53,12 @@ module "functionbeat" {
     }
 
     output_elasticsearch = {
-      hosts : ["https://your-endpoint:443"]
-      protocol : "https"
-      username : "elastic"
-      password : "mysupersecret"
+      hosts    = ["https://your-endpoint:443"]
+      protocol = "https"
+      username = "elastic"
+      password = "mysupersecret"
     }
+
   }
 
   loggroup_name = aws_cloudwatch_log_group.example_logs.name

examples/logstash.tf

@@ -0,0 +1,99 @@
+provider "aws" {
+  max_retries = 1337
+  region      = "eu-central-1"
+}
+
+resource "aws_vpc" "vpc" {
+  cidr_block = "172.16.0.0/16"
+  tags = {
+    Name = "Test-VPC"
+  }
+}
+
+resource "aws_subnet" "subnet" {
+  vpc_id            = aws_vpc.vpc.id
+  cidr_block        = cidrsubnet(aws_vpc.vpc.cidr_block, 8, 10)
+  availability_zone = "eu-central-1a"
+  tags = {
+    Name = "Private"
+  }
+}
+
+resource "aws_cloudwatch_log_group" "example_logs" {
+  name              = "MyExampleService"
+  retention_in_days = 1
+}
+
+resource "aws_security_group" "functionbeat_securitygroup" {
+  name   = "Functionbeat"
+  vpc_id = aws_vpc.vpc.id
+
+  egress {
+    from_port   = 443
+    protocol    = "tcp"
+    to_port     = 443
+    description = "HTTPS"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+}
+
+module "functionbeat" {
+  source = "../"
+
+  application_name     = "crazy-test-module"
+  functionbeat_version = "7.17.1"
+
+  lambda_config = {
+    name = "my-kibana-exporter"
+
+    vpc_config = {
+      vpc_id             = aws_vpc.vpc.id
+      subnet_ids         = [aws_subnet.subnet.id]
+      security_group_ids = [aws_security_group.functionbeat_securitygroup.id]
+    }
+
+    output_logstash = {
+      hosts       = ["10.0.0.1:5044", "10.0.0.2:5044"]
+      ssl.enabled = false
+    }
+  }
+
+  loggroup_name = aws_cloudwatch_log_group.example_logs.name
+
+  fb_extra_configuration = {
+    fields = {
+      env = "test",
+      foo = "bar"
+    }
+    setup = {
+      "template.settings" = {
+        "index.number_of_shards" : 1
+      }
+      ilm = {
+        enabled : true
+        rollover_alias : "my-alias"
+        pattern : "{now/d}-000001"
+        policy_name : "index_curation"
+      }
+    }
+    logging = {
+      to_syslog : false
+      to_eventlog : false
+    }
+    processors = [
+      {
+        add_cloud_metadata : null
+      },
+      {
+        add_fields = {
+          fields = {
+            id   = "574734885120952459"
+            name = "myproject"
+          }
+          target = "project"
+        }
+      }
+    ]
+  }
+  fb_extra_tags = ["webserver", "testme"]
+}

file/functionbeat.yml.tftpl

@@ -25,11 +25,22 @@ ${yamlencode({
 # Configure what output to use when sending the data collected by the beat.
 
 # ---------------------------- Elasticsearch Output ----------------------------
+
+%{ if output_elasticsearch != null }
 ${yamlencode({
     output = {
         elasticsearch = output_elasticsearch
     }
 })}
+%{ endif }
+
+%{ if output_logstash != null }
+${yamlencode({
+    output = {
+        logstash = output_logstash
+    }
+})}
+%{ endif }
 
 # ================================== Logging ===================================
 

main.tf

@@ -13,6 +13,7 @@ resource "local_file" "functionbeat_config" {
     enabled_function_name  = var.lambda_config.name
     application_name       = var.application_name
     output_elasticsearch   = var.lambda_config.output_elasticsearch
+    output_logstash        = var.lambda_config.output_logstash
     fb_transaction_tags    = var.fb_extra_tags
     fb_extra_configuration = var.fb_extra_configuration
   })

variables.tf

@@ -19,7 +19,8 @@ variable "lambda_config" {
       subnet_ids         = list(string)
       security_group_ids = list(string)
     })
-    output_elasticsearch = any
+    output_elasticsearch = optional(any)
+    output_logstash      = optional(any)
   })
 }