Terraform多个cloudwatch事件触发相同的lambda函数

Question

我已经在Terraform中设置了以下内容。所以有两个事件规则，早上8点开始事件，下午6点停止事件。

# Create cloudwatch event rules
resource "aws_cloudwatch_event_rule" "stop_ec2_event_rule" {
name        = "stop-ec2-event-rule"
description = "Stop EC2 instance at a specified time each day"
schedule_expression = var.cloudwatch_schedule_stop
}
resource "aws_cloudwatch_event_rule" "start_ec2_event_rule" {
name        = "start-ec2-event-rule"
description = "Start EC2 instance at a specified time each day"
schedule_expression = var.cloudwatch_schedule_start
}

每个事件都向lambda 传递一个操作

resource "aws_cloudwatch_event_target" "stop_ec2_event_rule_target" {
rule      = aws_cloudwatch_event_rule.stop_ec2_event_rule.name
target_id = "TriggerLambdaFunction"
arn       = aws_lambda_function.lambda_rscheduler.arn
input     = "{"environment":"${var.environment}", "action":"stop"}"
}
resource "aws_cloudwatch_event_target" "start_ec2_event_rule_target" {
rule      = aws_cloudwatch_event_rule.start_ec2_event_rule.name
target_id = "TriggerLambdaFunction"
arn       = aws_lambda_function.lambda_rscheduler.arn
input     = "{"environment":"${var.environment}", "action":"start"}"
}

这适用于

resource "aws_lambda_permission" "allow_cloudwatch" {
statement_id  = "AllowExecutionFromCloudWatch"
action        = "lambda:InvokeFunction"
function_name = aws_lambda_function.lambda_rscheduler.function_name
principal     = "events.amazonaws.com"
source_arn    = aws_cloudwatch_event_rule.stop_ec2_event_rule.arn

我面临的这个问题是，我无法让Terraform将start_event与lambda函数关联起来。我进入AWS控制台，可以手动将CloudWatch start_event触发器添加到lambda函数中。

如果我有启动事件资源

resource "aws_lambda_permission" "allow_cloudwatch" {
statement_id  = "AllowExecutionFromCloudWatch"
action        = "lambda:InvokeFunction"
function_name = aws_lambda_function.lambda_rscheduler.function_name
principal     = "events.amazonaws.com"
source_arn    = aws_cloudwatch_event_rule.start_ec2_event_rule.arn

它会抱怨statement_id重复。

我需要一些类似地形aws_lambda_event_source_mapping的东西，但它只允许lambda函数从Kinesis、DynamoDB和SQS获取事件；而不是CloudWatch事件。

如何告诉terraform将多个cloudwatch事件关联到同一个lambda函数；我什么时候可以从AWS控制台手动完成？

Answer 1

statement_id不是强制的，因此您可以安全地从aws_lambda_permission中省略它，地形将自动为您生成唯一的id。您也可以使用count或for_each为aws_lambda_permission节省一些输入。

例如，使用for_each可以将aws_lambda_permission定义为：

resource "aws_lambda_permission" "allow_cloudwatch" {

for_each      = {for idx, v in [
aws_cloudwatch_event_rule.stop_ec2_event_rule,
aws_cloudwatch_event_rule.start_ec2_event_rule
]: idx => v}

action        = "lambda:InvokeFunction"
function_name = aws_lambda_function.lambda_rscheduler.function_name
principal     = "events.amazonaws.com"
source_arn    = each.value.arn
}

可以为aws_cloudwatch_event_rule和aws_cloudwatch_event_target编写类似的版本，以便您的代码基于for_each或count，而不需要复制和粘贴重复。