Use EC2 instead of Fargate

ministryofjustice · Dec 13, 2023 · a3d2223 · a3d2223
1 parent bf3857f
commit a3d2223
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Showing 2 changed files with 63 additions and 7 deletions.
diff --git a/terraform/environments/cdpt-chaps/application_variables.json b/terraform/environments/cdpt-chaps/application_variables.json
@@ -2,15 +2,27 @@
   "accounts": {
     "development": {
       "region": "eu-west-2",
-      "docker_image_tag": "development"
+      "docker_image_tag": "development",
+      "app_count": 1,
+      "ec2_desired_capacity": 2,
+      "ec2_max_size": 3,
+      "ec2_min_size": 2
     },
     "preproduction": {
       "region": "eu-west-2",
-      "docker_image_tag": "preproduction"
+      "docker_image_tag": "preproduction",
+      "app_count": 1,
+      "ec2_desired_capacity": 2,
+      "ec2_max_size": 3,
+      "ec2_min_size": 2
     },
     "production": {
       "region": "eu-west-2",
-      "docker_image_tag": "production"
+      "docker_image_tag": "production",
+      "app_count": 1,
+      "ec2_desired_capacity": 2,
+      "ec2_max_size": 3,
+      "ec2_min_size": 2
     }
   }
 }
diff --git a/terraform/environments/cdpt-chaps/ecs.tf b/terraform/environments/cdpt-chaps/ecs.tf
@@ -18,7 +18,7 @@ resource "aws_cloudwatch_log_group" "deployment_logs" {
 
 resource "aws_ecs_task_definition" "chaps_task_definition" {
   family                   = "chapsFamily"
-  requires_compatibilities = ["FARGATE"]
+  requires_compatibilities = ["EC2"]
   network_mode             = "awsvpc"
   execution_role_arn       = aws_iam_role.app_execution.arn
   task_role_arn            = aws_iam_role.app_task.arn
@@ -64,11 +64,15 @@ resource "aws_ecs_service" "ecs_service" {
   name                              = var.networking[0].application
   cluster                           = aws_ecs_cluster.ecs_cluster.id
   task_definition                   = aws_ecs_task_definition.chaps_task_definition.arn
-  launch_type                       = "FARGATE"
-  enable_execute_command            = true
-  desired_count                     = 2
+  launch_type                       = "EC2"
+  desired_count                     = local.application_data.accounts[local.environment].app_count
   health_check_grace_period_seconds = 180
 
+  capacity_provider_strategy {
+    capacity_provider = aws_ecs_capacity_provider.cdpt-chaps.name
+    weight            = 1
+  }
+
   network_configuration {
     subnets          = data.aws_subnets.shared-public.ids
     security_groups  = [aws_security_group.ecs_service.id]
@@ -82,6 +86,46 @@ resource "aws_ecs_service" "ecs_service" {
   }
 }
 
+resource "aws_ecs_capacity_provider" "cdpt-chaps" {
+  name = "${local.application_name}-capacity-provider"
+
+  auto_scaling_group_provider {
+    auto_scaling_group_arn         = aws_autoscaling_group.cluster-scaling-group.arn
+    managed_termination_protection = "ENABLED"
+
+    managed_scaling {
+      status          = "ENABLED"
+      target_capacity = 100
+    }
+  }
+}
+
+resource "aws_ecs_cluster_capacity_providers" "cdpt-chaps" {
+  cluster_name = aws_ecs_cluster.ecs_cluster.name
+
+  capacity_providers = [aws_ecs_capacity_provider.apex.name]
+}
+
+resource "aws_autoscaling_group" "cluster-scaling-group" {
+  vpc_zone_identifier   = sort(data.aws_subnets.shared-private.ids)
+  name                  = "${local.application_name}-cluster-scaling-group"
+  desired_capacity      = local.application_data.accounts[local.environment].ec2_desired_capacity
+  max_size              = local.application_data.accounts[local.environment].ec2_max_size
+  min_size              = local.application_data.accounts[local.environment].ec2_min_size
+  protect_from_scale_in = true
+
+  launch_template {
+    id      = aws_launch_template.ec2-launch-template.id
+    version = "$Latest"
+  }
+
+  tag {
+    key                 = "AmazonECSManaged"
+    value               = true
+    propagate_at_launch = true
+  }
+}
+
 resource "aws_iam_role" "app_execution" {
   name = "execution-${var.networking[0].application}"