我正在尝试使用服务创建ECS群集,但我无法设置自动缩放,因此群集中不会启动任何实例:
service my_service无法放置任务,因为没有容器实例满足其所有要求。原因:您的群集中未找到任何容器实例。有关更多信息,请参阅“故障排除”部分
这是我的Terraform配置(仅限相关配置):
集群和服务
resource "aws_ecs_cluster" "my_cluster" {
name = "my_cluster"
}
resource "aws_ecs_service" "my_service" {
name = "my_service"
cluster = "${aws_ecs_cluster.my_cluster.id}"
task_definition = "${aws_ecs_task_definition.my_tf.arn}"
desired_count = 1
iam_role = "${aws_iam_role.ecs-service-role.id}"
}
自动缩放
resource "aws_launch_configuration" "launch_config" {
name_prefix = "my_lc"
image_id = "${data.aws_ami.ubuntu.id}"
instance_type = "t2.micro"
user_data = "${data.template_file.user_data.rendered}"
security_groups = ["${aws_security_group.my_sg.id}"]
iam_instance_profile = "${aws_iam_instance_profile.ecs-instance-profile.id}"
lifecycle {
create_before_destroy = true
}
}
resource "aws_autoscaling_group" "autoscaling_group" {
name = "my_autoscaling_group"
max_size = 2
min_size = 1
launch_configuration = "${aws_launch_configuration.launch_config.name}"
vpc_zone_identifier = ["${aws_subnet.public.id}"]
}
data "template_file" "user_data" {
template = "${file("${path.module}/templates/user-data.sh")}"
vars {
cluster_name = "${aws_ecs_cluster.my_cluster.name}"
}
}
模板/ user-data.sh
#!/bin/bash
# ECS config
{
echo "ECS_CLUSTER=${cluster_name}"
} >> /etc/ecs/ecs.config
start ecs
AMI
data "aws_ami" "ubuntu" {
most_recent = true
filter {
name = "name"
values = ["ubuntu/images/hvm-ssd/ubuntu-trusty-14.04-amd64-server-*"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
owners = ["099720109477"]
}
据我所知,集群和Autoscaling Group在启动配置中通过user_data
链接,但它似乎无法正常工作。
我错过了什么?
您需要一个ECS优化AMI:https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-optimized_AMI.html
要么
你需要创建自己的AMI并不容易。
为了使其工作,您缺少一个关键组件。 Cloudwatch警报
Cloudwatch会提醒自动缩放组在需要时采取措施。配置示例:
这将创建必要的警报,以便在机器未充分利用时缩小。通过vars调整您的需求。
resource "aws_cloudwatch_metric_alarm" "alarm-cpu-down" {
alarm_name = "ecs-down"
comparison_operator = "LessThanOrEqualToThreshold"
evaluation_periods = "${var.evaluation_periods}"
metric_name = "${var.metric_name}"
namespace = "${var.namespace}"
period = "${var.period_down}"
statistic = "${var.statistic}"
threshold = "${var.threshold_down}"
dimensions = "${map(var.dimension_name, var.dimension_value == "false" ? var.autoscaling_group_name[count.index] : var.dimension_value)}"
alarm_description = "This metric monitors CPU utilization down"
alarm_actions = ["${aws_autoscaling_policy.down-scale.*.arn}"]
}
当需要机器时,这将创建必要的警报以扩大规模(CPUReservation(=您的服务需要的是什么)比可用的更大)
resource "aws_cloudwatch_metric_alarm" "alarm-cpu-up" {
alarm_name = "${var.environment}-${var.project}-${var.name}-${var.metric_name}-up${count.index}"
comparison_operator = "GreaterThanOrEqualToThreshold"
evaluation_periods = "${var.evaluation_periods}"
metric_name = "${var.metric_name}"
namespace = "${var.namespace}"
period = "${var.period_up}"
statistic = "${var.statistic}"
threshold = "${var.threshold_up}"
dimensions = "${map(var.dimension_name, var.dimension_value == "false" ? var.autoscaling_group_name[count.index] : var.dimension_value)}"
alarm_description = "This metric monitors CPU utilization up"
alarm_actions = ["${aws_autoscaling_policy.up-scale.*.arn}"]
}
这些是实际的自动缩放策略。这是触发警报时cloudwatch警报需要执行的操作。
resource "aws_autoscaling_policy" "up-scale" {
count = "${var.num_asg}"
name = "${var.environment}-${var.project}-${var.name}-${var.metric_name}-up${count.index}"
autoscaling_group_name = "${var.autoscaling_group_name[count.index]}"
adjustment_type = "${var.adjustment_type}"
policy_type = "${var.policy_type}"
cooldown = "${var.cooldown_up}"
scaling_adjustment = "${var.adjustment_up}"
}
resource "aws_autoscaling_policy" "down-scale" {
count = "${var.num_asg}"
name = "${var.environment}-${var.project}-${var.name}-${var.metric_name}-down${count.index}"
autoscaling_group_name = "${var.autoscaling_group_name[count.index]}"
adjustment_type = "${var.adjustment_type}"
policy_type = "${var.policy_type}"
cooldown = "${var.cooldown_down}"
scaling_adjustment = "${var.adjustment_down}"
}