main.tf

# NOTA BENE: The eight aws_ecs_service resources below are mutually
# exclusive. One and only one will ever be built.
#
# This code was tested with Terraform v0.11.3
# https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs_services.html

# This resource is conditionally built when using awsvpc network
# mode with a load balancer and service discovery (e.g., works with
# FARGATE and EC2 launch_type). This is primarily useful for testing.

resource "aws_ecs_service" "awsvpc_all" {
  count = local.network_mode == "awsvpc" && length(var.load_balancer) > 0 && length(var.service_discovery) > 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  load_balancer {
    container_name   = local.container_name
    container_port   = local.container_port
    target_group_arn = aws_lb_target_group.default[0].arn
  }

  network_configuration {
    assign_public_ip = local.assign_public_ip
    security_groups  = local.security_groups
    subnets          = local.all_subnets
  }

  service_registries {
    registry_arn = element(
      concat(
        aws_service_discovery_service.default.*.arn,
        aws_service_discovery_service.health_check.*.arn,
        aws_service_discovery_service.health_check_custom.*.arn,
        aws_service_discovery_service.health_check_and_health_check_custom.*.arn,
      ),
      0,
    )
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when using awsvpc network mode
# with a load balancer (e.g., works with FARGATE and EC2 launch_type).

resource "aws_ecs_service" "awsvpc_lb" {
  count = local.network_mode == "awsvpc" && length(var.load_balancer) > 0 && length(var.service_discovery) == 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  load_balancer {
    container_name   = local.container_name
    container_port   = local.container_port
    target_group_arn = aws_lb_target_group.default[0].arn
  }

  network_configuration {
    assign_public_ip = local.assign_public_ip
    security_groups  = local.security_groups
    subnets          = local.all_subnets
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when using awsvpc network mode
# with service discovery (which implies no load balancer).

resource "aws_ecs_service" "awsvpc_sd" {
  count = local.network_mode == "awsvpc" && length(var.load_balancer) == 0 && length(var.service_discovery) > 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  network_configuration {
    assign_public_ip = local.assign_public_ip
    security_groups  = local.security_groups
    subnets          = local.all_subnets
  }

  service_registries {
    registry_arn = element(
      concat(
        aws_service_discovery_service.default.*.arn,
        aws_service_discovery_service.health_check.*.arn,
        aws_service_discovery_service.health_check_custom.*.arn,
        aws_service_discovery_service.health_check_and_health_check_custom.*.arn,
      ),
      0,
    )
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when using awsvpc network
# mode without a load balancer or service discovery.

resource "aws_ecs_service" "awsvpc" {
  count = local.network_mode == "awsvpc" && length(var.load_balancer) == 0 && length(var.service_discovery) == 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  network_configuration {
    assign_public_ip = local.assign_public_ip
    security_groups  = local.security_groups
    subnets          = local.all_subnets
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when not using awsvpc network
# mode, with a load balancer and service discovery (e.g., bridge
# or host mode: only works with launch_type EC2).

resource "aws_ecs_service" "all" {
  count = local.network_mode != "awsvpc" && length(var.load_balancer) > 0 && length(var.service_discovery) > 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  load_balancer {
    container_name   = local.container_name
    container_port   = local.container_port
    target_group_arn = aws_lb_target_group.default[0].arn
  }

  service_registries {
    registry_arn = element(
      concat(
        aws_service_discovery_service.default.*.arn,
        aws_service_discovery_service.health_check.*.arn,
        aws_service_discovery_service.health_check_custom.*.arn,
        aws_service_discovery_service.health_check_and_health_check_custom.*.arn,
      ),
      0,
    )
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when not using awsvpc network
# mode, with a load balancer (e.g., bridge or host mode: only works
# with launch_type EC2).

resource "aws_ecs_service" "lb" {
  count = local.network_mode != "awsvpc" && length(var.load_balancer) > 0 && length(var.service_discovery) == 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  load_balancer {
    container_name   = local.container_name
    container_port   = local.container_port
    target_group_arn = aws_lb_target_group.default[0].arn
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when not using awsvpc network mode
# with service discovery (which implies no load balancer). This applies to
# bridge, host, and none modes, and only works with launch_type EC2.

resource "aws_ecs_service" "sd" {
  count = local.network_mode != "awsvpc" && length(var.load_balancer) == 0 && length(var.service_discovery) > 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  service_registries {
    registry_arn = element(
      concat(
        aws_service_discovery_service.default.*.arn,
        aws_service_discovery_service.health_check.*.arn,
        aws_service_discovery_service.health_check_custom.*.arn,
        aws_service_discovery_service.health_check_and_health_check_custom.*.arn,
      ),
      0,
    )
  }

  tags = merge({ "Name" = var.name }, var.tags)
}

# This resource is conditionally built when not using awsvpc network
# mode without a load balancer or service discovery. This applies
# to bridge, host, and none modes, and only works with launch_type
# EC2. This is useful when running backend services that do not
# require inbound traffic.

resource "aws_ecs_service" "default" {
  count = local.network_mode != "awsvpc" && length(var.load_balancer) == 0 && length(var.service_discovery) == 0 ? 1 : 0

  name            = var.name
  launch_type     = var.launch_type
  cluster         = data.aws_ecs_cluster.selected.id
  task_definition = var.task_definition_arn == "" ? local.task_definition_arn : var.task_definition_arn
  desired_count   = var.desired_count

  deployment_maximum_percent         = var.deployment_maximum_percent
  deployment_minimum_healthy_percent = var.deployment_minimum_healthy_percent
  health_check_grace_period_seconds  = var.health_check_grace_period_seconds

  dynamic "placement_constraints" {
    for_each = var.placement_constraints
    content {
      expression = lookup(placement_constraints.value, "expression", null)
      type       = placement_constraints.value.type
    }
  }

  dynamic "ordered_placement_strategy" {
    for_each = var.ordered_placement_strategy
    content {
      field = lookup(ordered_placement_strategy.value, "field", null)
      type  = ordered_placement_strategy.value.type
    }
  }

  platform_version = var.platform_version

  tags = merge({ "Name" = var.name }, var.tags)
}