diff --git a/main.tf b/main.tf
index d17b3aa..4c2a188 100644
--- a/main.tf
+++ b/main.tf
@@ -43,7 +43,7 @@ resource "aws_sqs_queue" "airflow_queue" {
 # ---------------------------------------
 
 module "ami_instance_profile" {
-  source         = "git::https://github.com/traveloka/terraform-aws-iam-role//modules/instance?ref=tags/v1.0.1"
+  source         = "git::https://github.com/traveloka/terraform-aws-iam-role//modules/instance?ref=tags/v1.0.2"
   service_name   = "${module.airflow_labels.namespace}"
   cluster_role   = "${module.airflow_labels.stage}"
   environment    = "${module.airflow_labels.stage}"
@@ -86,16 +86,16 @@ POLICY
 # ----------------------------------------------------------------------------------------
 
 module "sg_airflow" {
-  source = "terraform-aws-modules/security-group/aws"
-  version = "3.1.0"
-  name = "${module.airflow_labels.id}-sg"
-  description = "Security group for ${module.airflow_labels.id} machines"
-  vpc_id = "${data.aws_vpc.default.id}"
-  ingress_cidr_blocks = "${var.ingress_cidr_blocks}"
-  ingress_rules = ["http-80-tcp", "https-443-tcp", "ssh-tcp"]
+  source                   = "terraform-aws-modules/security-group/aws"
+  version                  = "3.2.0"
+  name                     = "${module.airflow_labels.id}-sg"
+  description              = "Security group for ${module.airflow_labels.id} machines"
+  vpc_id                   = "${data.aws_vpc.default.id}"
+  ingress_cidr_blocks      = "${var.ingress_cidr_blocks}"
+  ingress_rules            = ["http-80-tcp", "https-443-tcp", "ssh-tcp"]
   ingress_with_cidr_blocks = "${var.ingress_with_cidr_blocks}"
-  egress_rules = ["all-all"]
-  tags = "${module.airflow_labels.tags}"
+  egress_rules             = ["all-all"]
+  tags                     = "${module.airflow_labels.tags}"
 }
 
 #-------------------------------------------------------------------------
@@ -104,71 +104,71 @@ module "sg_airflow" {
 resource "aws_instance" "airflow_webserver" {
   count = 1
 
-  instance_type = "${var.webserver_instance_type}"
-  ami = "${var.ami}"
-  key_name = "${aws_key_pair.auth.id}"
+  instance_type          = "${var.webserver_instance_type}"
+  ami                    = "${var.ami}"
+  key_name               = "${aws_key_pair.auth.id}"
   vpc_security_group_ids = ["${module.sg_airflow.this_security_group_id}"]
-  subnet_id = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
-  iam_instance_profile = "${module.ami_instance_profile.instance_profile_name}"
+  subnet_id              = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
+  iam_instance_profile   = "${module.ami_instance_profile.instance_profile_name}"
 
   associate_public_ip_address = true
 
   volume_tags = "${module.airflow_labels_webserver.tags}"
 
   root_block_device {
-    volume_type = "${var.root_volume_type}"
-    volume_size = "${var.root_volume_size}"
+    volume_type           = "${var.root_volume_type}"
+    volume_size           = "${var.root_volume_size}"
     delete_on_termination = "${var.root_volume_delete_on_termination}"
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_env.rendered}"
+    content     = "${data.template_file.custom_env.rendered}"
     destination = "/tmp/custom_env"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_requirements.rendered}"
+    content     = "${data.template_file.custom_requirements.rendered}"
     destination = "/tmp/requirements.txt"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_environment.rendered}"
+    content     = "${data.template_file.airflow_environment.rendered}"
     destination = "/tmp/airflow_environment"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_service.rendered}"
+    content     = "${data.template_file.airflow_service.rendered}"
     destination = "/tmp/airflow.service"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
@@ -179,16 +179,16 @@ resource "aws_instance" "airflow_webserver" {
     ]
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   user_data = "${data.template_file.provisioner.rendered}"
-  tags = "${module.airflow_labels_webserver.tags}"
+  tags      = "${module.airflow_labels_webserver.tags}"
 
   lifecycle {
     create_before_destroy = true
@@ -198,71 +198,71 @@ resource "aws_instance" "airflow_webserver" {
 resource "aws_instance" "airflow_scheduler" {
   count = 1
 
-  instance_type = "${var.scheduler_instance_type}"
-  ami = "${var.ami}"
-  key_name = "${aws_key_pair.auth.id}"
+  instance_type          = "${var.scheduler_instance_type}"
+  ami                    = "${var.ami}"
+  key_name               = "${aws_key_pair.auth.id}"
   vpc_security_group_ids = ["${module.sg_airflow.this_security_group_id}"]
-  subnet_id = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
-  iam_instance_profile = "${module.ami_instance_profile.instance_profile_name}"
+  subnet_id              = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
+  iam_instance_profile   = "${module.ami_instance_profile.instance_profile_name}"
 
   associate_public_ip_address = true
 
   volume_tags = "${module.airflow_labels_webserver.tags}"
 
   root_block_device {
-    volume_type = "${var.root_volume_type}"
-    volume_size = "${var.root_volume_size}"
+    volume_type           = "${var.root_volume_type}"
+    volume_size           = "${var.root_volume_size}"
     delete_on_termination = "${var.root_volume_delete_on_termination}"
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_env.rendered}"
+    content     = "${data.template_file.custom_env.rendered}"
     destination = "/tmp/custom_env"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_requirements.rendered}"
+    content     = "${data.template_file.custom_requirements.rendered}"
     destination = "/tmp/requirements.txt"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_environment.rendered}"
+    content     = "${data.template_file.airflow_environment.rendered}"
     destination = "/tmp/airflow_environment"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_service.rendered}"
+    content     = "${data.template_file.airflow_service.rendered}"
     destination = "/tmp/airflow.service"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
@@ -273,16 +273,16 @@ resource "aws_instance" "airflow_scheduler" {
     ]
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   user_data = "${data.template_file.provisioner.rendered}"
-  tags = "${module.airflow_labels_scheduler.tags}"
+  tags      = "${module.airflow_labels_scheduler.tags}"
 
   lifecycle {
     create_before_destroy = true
@@ -292,71 +292,71 @@ resource "aws_instance" "airflow_scheduler" {
 resource "aws_instance" "airflow_worker" {
   count = "${var.worker_instance_count}"
 
-  instance_type = "${var.worker_instance_type}"
-  ami = "${var.ami}"
-  key_name = "${aws_key_pair.auth.id}"
+  instance_type          = "${var.worker_instance_type}"
+  ami                    = "${var.ami}"
+  key_name               = "${aws_key_pair.auth.id}"
   vpc_security_group_ids = ["${module.sg_airflow.this_security_group_id}"]
-  subnet_id = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
-  iam_instance_profile = "${module.ami_instance_profile.instance_profile_name}"
+  subnet_id              = coalesce("${var.instance_subnet_id}", "${tolist(data.aws_subnet_ids.selected.ids)[count.index]}")
+  iam_instance_profile   = "${module.ami_instance_profile.instance_profile_name}"
 
   associate_public_ip_address = true
 
   volume_tags = "${module.airflow_labels_webserver.tags}"
 
   root_block_device {
-    volume_type = "${var.root_volume_type}"
-    volume_size = "${var.root_volume_size}"
+    volume_type           = "${var.root_volume_type}"
+    volume_size           = "${var.root_volume_size}"
     delete_on_termination = "${var.root_volume_delete_on_termination}"
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_env.rendered}"
+    content     = "${data.template_file.custom_env.rendered}"
     destination = "/tmp/custom_env"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.custom_requirements.rendered}"
+    content     = "${data.template_file.custom_requirements.rendered}"
     destination = "/tmp/requirements.txt"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_environment.rendered}"
+    content     = "${data.template_file.airflow_environment.rendered}"
     destination = "/tmp/airflow_environment"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   provisioner "file" {
-    content = "${data.template_file.airflow_service.rendered}"
+    content     = "${data.template_file.airflow_service.rendered}"
     destination = "/tmp/airflow.service"
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
@@ -367,16 +367,16 @@ resource "aws_instance" "airflow_worker" {
     ]
 
     connection {
-      host = "${self.public_ip}"
-      agent = false
-      type = "ssh"
-      user = "ubuntu"
+      host        = "${self.public_ip}"
+      agent       = false
+      type        = "ssh"
+      user        = "ubuntu"
       private_key = "${file(var.private_key_path)}"
     }
   }
 
   user_data = "${data.template_file.provisioner.rendered}"
-  tags = "${module.airflow_labels_worker.tags}"
+  tags      = "${module.airflow_labels_worker.tags}"
 
   lifecycle {
     create_before_destroy = true
@@ -392,38 +392,39 @@ resource "aws_instance" "airflow_worker" {
 # -------------------------------------------------------------------------
 
 module "sg_database" {
-  source = "terraform-aws-modules/security-group/aws"
-  name = "${module.airflow_labels.id}-database-sg"
-  description = "Security group for ${module.airflow_labels.id} database"
-  vpc_id = "${data.aws_vpc.default.id}"
-  ingress_cidr_blocks = "${var.ingress_cidr_blocks}"
+  source                                                   = "terraform-aws-modules/security-group/aws"
+  version                                                  = "3.2.0"
+  name                                                     = "${module.airflow_labels.id}-database-sg"
+  description                                              = "Security group for ${module.airflow_labels.id} database"
+  vpc_id                                                   = "${data.aws_vpc.default.id}"
+  ingress_cidr_blocks                                      = "${var.ingress_cidr_blocks}"
   number_of_computed_ingress_with_source_security_group_id = 1
   computed_ingress_with_source_security_group_id = [
     {
-      rule = "postgresql-tcp"
+      rule                     = "postgresql-tcp"
       source_security_group_id = "${module.sg_airflow.this_security_group_id}"
-      description = "Allow ${module.airflow_labels.id} machines"
+      description              = "Allow ${module.airflow_labels.id} machines"
     }
   ]
   tags = "${module.airflow_labels.tags}"
 }
 
 resource "aws_db_instance" "airflow_database" {
-  identifier = "${module.airflow_labels.id}-db"
-  allocated_storage = "${var.db_allocated_storage}"
-  engine = "postgres"
-  engine_version = "11.1"
-  instance_class = "${var.db_instance_type}"
-  name = "${var.db_dbname}"
-  username = "${var.db_username}"
-  password = "${var.db_password}"
-  storage_type = "gp2"
-  backup_retention_period = 14
-  multi_az = false
-  publicly_accessible = false
-  apply_immediately = true
-  skip_final_snapshot = true
-  vpc_security_group_ids = ["${module.sg_database.this_security_group_id}"]
-  port = "5432"
-  db_subnet_group_name = "${var.db_subnet_group_name}"
+  identifier              = "${module.airflow_labels.id}-db"
+  allocated_storage       = "${var.db_allocated_storage}"
+  engine                  = "postgres"
+  engine_version          = "11.5"
+  instance_class          = "${var.db_instance_type}"
+  name                    = "${var.db_dbname}"
+  username                = "${var.db_username}"
+  password                = "${var.db_password}"
+  storage_type            = "gp2"
+  backup_retention_period = 7
+  multi_az                = false
+  publicly_accessible     = false
+  apply_immediately       = true
+  skip_final_snapshot     = true
+  vpc_security_group_ids  = ["${module.sg_database.this_security_group_id}"]
+  port                    = "5432"
+  db_subnet_group_name    = "${var.db_subnet_group_name}"
 }