Addressed issues related to single node deployment

* Removed unused resource
* Fixed graphdb.properties values for single node deployment
* Removed calculation of `lb_tls_enabled` in the LB module as it is calculated in the main.tf
* Replaced `monitoring_route53_healtcheck_fqdn_url` with `graphdb_external_address` as it is the same URL.
* Removed `monitoring_route53_healtcheck_fqdn_url` variable
* Introduced new variable `graphdb_external_address`
* Moved proxy config file to be created only when node count > 1
* Removed port from graphdb.external-url for single node

CHANGELOG.md

@@ -1,5 +1,14 @@
 # GraphDB AWS Terraform Module Changelog
 
+# 1.2.3
+
+* Removed unused resource "aws_ssm_parameter" "graphdb_lb_dns_name"
+* Fixed `graphdb.properties` values for single node deployment:
+  * Changed `graphdb.external-url` to use `LB_DNS_RECORD` when single node is deployed.
+  * Added `graphdb.external-url.enforce.transactions=true`
+* Removed calculation of `lb_tls_enabled` in the LB module as it is calculated in the main.tf
+* Removed `monitoring_route53_healtcheck_fqdn_url` in favor of `graphdb_external_dns`.
+
 # 1.2.2
 
 * Fixed issues with variables in the backup user data script

main.tf

@@ -165,6 +165,11 @@ module "backup_replication" {
   versioning_enabled        = var.s3_versioning_enabled
 }
 
+locals {
+  lb_tls_enabled              = var.lb_tls_certificate_arn != "" ? true : false
+  calculated_http_string_type = local.lb_tls_enabled == true ? "HTTPS" : "HTTP"
+}
+
 module "load_balancer" {
   source = "./modules/load_balancer"
 
@@ -177,6 +182,7 @@ module "load_balancer" {
   lb_health_check_interval      = var.lb_health_check_interval
   lb_enable_deletion_protection = var.prevent_resource_deletion
   lb_tls_certificate_arn        = var.lb_tls_certificate_arn
+  lb_tls_enabled                = local.lb_tls_enabled
   lb_tls_policy                 = var.lb_tls_policy
   lb_access_logs_bucket_name    = var.lb_enable_access_logs && var.deploy_logging_module ? module.logging[0].graphdb_logging_bucket_name : null
   lb_enable_access_logs         = var.lb_enable_access_logs
@@ -189,11 +195,6 @@ locals {
   )
 }
 
-locals {
-  lb_tls_enabled              = var.lb_tls_certificate_arn != null ? true : false
-  calculated_http_string_type = local.lb_tls_enabled == true ? "HTTPS" : "HTTP"
-}
-
 module "monitoring" {
   source = "./modules/monitoring"
   providers = {
@@ -221,11 +222,11 @@ module "monitoring" {
   cmk_key_alias                          = var.sns_cmk_key_alias
   parameter_store_kms_key_arn            = local.calculated_parameter_store_kms_key_arn
   cloudwatch_log_group_retention_in_days = var.monitoring_log_group_retention_in_days
-  route53_availability_request_url       = var.monitoring_route53_healtcheck_fqdn_url
+  route53_availability_request_url       = var.graphdb_external_dns
   route53_availability_measure_latency   = var.monitoring_route53_measure_latency
   sns_kms_key_arn                        = local.calculated_sns_kms_key_arn
   graphdb_node_count                     = var.graphdb_node_count
-  route53_availability_http_string_type  = local.calculated_http_string_type
+  route53_availability_http_string_type  = local.calculated_protocol
   lb_tls_certificate_arn                 = var.lb_tls_certificate_arn
   lb_dns_name                            = module.load_balancer.lb_dns_name != "" ? module.load_balancer.lb_dns_name : null
 }
@@ -248,7 +249,7 @@ module "graphdb" {
   # Network Load Balancer
   lb_enable_private_access = var.lb_internal ? var.lb_enable_private_access : false
   lb_subnets               = local.lb_subnets
-  graphdb_lb_dns_name      = module.load_balancer.lb_dns_name
+  graphdb_lb_dns_name      = var.graphdb_external_dns != "" ? var.graphdb_external_dns : module.load_balancer.lb_dns_name
 
   # GraphDB Configurations
 
@@ -309,7 +310,8 @@ module "graphdb" {
 
   # User data scripts
 
-  deploy_monitoring = var.deploy_monitoring
+  deploy_monitoring                 = var.deploy_monitoring
+  external_address_http_string_type = local.calculated_protocol
 
   # S3 Replication Logging Bucket Policy
 

modules/graphdb/config.tf

@@ -39,13 +39,6 @@ resource "aws_ssm_parameter" "graphdb_license" {
   key_id      = var.parameter_store_key_arn
 }
 
-resource "aws_ssm_parameter" "graphdb_lb_dns_name" {
-  name        = "/${var.resource_name_prefix}/graphdb/lb_dns_name"
-  description = "The DNS name of the load balancer for the GraphDB nodes."
-  type        = "String"
-  value       = var.graphdb_lb_dns_name
-}
-
 resource "aws_ssm_parameter" "graphdb_properties" {
   count = var.graphdb_properties_path != null ? 1 : 0
 

modules/graphdb/templates/04_gdb_conf_overrides.sh.tpl

@@ -22,7 +22,7 @@ echo "#######################################"
 
 LB_DNS_RECORD=${graphdb_lb_dns_name}
 NODE_DNS_RECORD=$(cat /var/opt/graphdb/node_dns)
-
+PROTOCOL=$(echo "${external_address_http_string_type}" | awk '{print tolower($0)}')
 # Get and store the GraphDB license
 aws --cli-connect-timeout 300 ssm get-parameter --region ${region} --name "/${name}/graphdb/license" --with-decryption | \
   jq -r .Parameter.Value | \
@@ -32,22 +32,34 @@ aws --cli-connect-timeout 300 ssm get-parameter --region ${region} --name "/${na
 GRAPHDB_CLUSTER_TOKEN="$(aws --cli-connect-timeout 300 ssm get-parameter --region ${region} --name "/${name}/graphdb/cluster_token" --with-decryption | jq -r .Parameter.Value | base64 -d)"
 # Get the NODE_DNS_RECORD value from the previous script
 SSM_PARAMETERS=$(aws ssm describe-parameters --cli-connect-timeout 300 --region ${region} --query "Parameters[?starts_with(Name, '/${name}/graphdb/')].Name" --output text)
+NODE_COUNT=$(aws autoscaling describe-auto-scaling-groups --auto-scaling-group-names ${name} --query "AutoScalingGroups[0].DesiredCapacity" --output text)
+
 
-cat << EOF > /etc/graphdb/graphdb.properties
+# graphdb.external-url.enforce.transactions: determines whether it is necessary to rewrite the Location header when no proxy is configured.
+# This is required because when working with the GDB transaction endpoint it returns an erroneous URL with HTTP protocol instead of HTTPS
+if [ "$NODE_COUNT" -eq 1 ]; then
+  cat << EOF > /etc/graphdb/graphdb.properties
+graphdb.connector.port=7201
+graphdb.external-url=$${PROTOCOL}://$${LB_DNS_RECORD}
+graphdb.external-url.enforce.transactions=true
+EOF
+else
+  cat << EOF > /etc/graphdb/graphdb.properties
 graphdb.auth.token.secret=$GRAPHDB_CLUSTER_TOKEN
 graphdb.connector.port=7201
-graphdb.external-url=http://$${NODE_DNS_RECORD}:7201
+graphdb.external-url=$${PROTOCOL}://$${NODE_DNS_RECORD}:7201
 graphdb.rpc.address=$${NODE_DNS_RECORD}:7301
 EOF
 
-cat << EOF > /etc/graphdb-cluster-proxy/graphdb.properties
+  cat << EOF > /etc/graphdb-cluster-proxy/graphdb.properties
 graphdb.auth.token.secret=$GRAPHDB_CLUSTER_TOKEN
 graphdb.connector.port=7200
 graphdb.external-url=http://$${LB_DNS_RECORD}
 graphdb.vhosts=http://$${LB_DNS_RECORD},http://$${NODE_DNS_RECORD}:7200
 graphdb.rpc.address=$${NODE_DNS_RECORD}:7300
 graphdb.proxy.hosts=$${NODE_DNS_RECORD}:7301
 EOF
+fi
 
 mkdir -p /etc/systemd/system/graphdb.service.d/
 

modules/graphdb/user_data.tf

@@ -61,6 +61,7 @@ data "cloudinit_config" "graphdb_user_data" {
     content = templatefile("${path.module}/templates/04_gdb_conf_overrides.sh.tpl", {
       name : var.resource_name_prefix
       region : var.aws_region
+      external_address_http_string_type : var.external_address_http_string_type
       graphdb_lb_dns_name : var.graphdb_lb_dns_name
     })
   }

modules/graphdb/variables.tf

@@ -168,6 +168,13 @@ variable "route53_zone_dns_name" {
   type        = string
 }
 
+# User Data Parameters
+
+variable "external_address_http_string_type" {
+  description = "External address HTTP string type"
+  type        = string
+}
+
 # Optional Parameters
 
 variable "backup_retention_count" {

modules/load_balancer/main.tf

@@ -11,7 +11,6 @@ resource "random_id" "tg_name_suffix" {
 locals {
   lb_name           = var.resource_name_prefix
   target_group_name = "${var.resource_name_prefix}-tg-${random_id.tg_name_suffix.hex}"
-  lb_tls_enabled    = var.lb_tls_certificate_arn != null ? true : false
 }
 
 resource "aws_lb" "graphdb_lb" {
@@ -55,7 +54,7 @@ resource "aws_lb_target_group" "graphdb_lb_target_group" {
 }
 
 resource "aws_lb_listener" "graphdb_listener" {
-  count = local.lb_tls_enabled ? 0 : 1
+  count = var.lb_tls_enabled ? 0 : 1
 
   load_balancer_arn = aws_lb.graphdb_lb.id
   port              = 80
@@ -68,7 +67,7 @@ resource "aws_lb_listener" "graphdb_listener" {
 }
 
 resource "aws_lb_listener" "graphdb_tls" {
-  count = local.lb_tls_enabled ? 1 : 0
+  count = var.lb_tls_enabled ? 1 : 0
 
   load_balancer_arn = aws_lb.graphdb_lb.id
   port              = 443

modules/load_balancer/variables.tf

@@ -89,3 +89,8 @@ variable "graphdb_node_count" {
   description = "Number of GraphDB nodes to deploy in ASG"
   type        = number
 }
+
+variable "lb_tls_enabled" {
+  description = "Is TLS enabled for the LB"
+  type        = bool
+}

variables.tf

@@ -306,6 +306,12 @@ variable "route53_zone_dns_name" {
   }
 }
 
+variable "graphdb_external_dns" {
+  description = "External address where GraphDB will be accessed"
+  type        = string
+  default     = ""
+}
+
 # Monitoring
 
 variable "deploy_monitoring" {
@@ -374,11 +380,6 @@ variable "monitoring_route53_availability_https_port" {
   default     = 443
 }
 
-variable "monitoring_route53_healtcheck_fqdn_url" {
-  description = "Define custom domain name for the Route53 Health check"
-  type        = string
-}
-
 # GraphDB overrides
 
 variable "graphdb_properties_path" {