如何覆蓋Terraform模塊中的資源？

Question

我有這樣的Terraform模塊：

module "helloworld" { 
    source = ../service" 
} 

和../service包含：

resource "aws_cloudwatch_metric_alarm" "cpu_max" { 
    comparison_operator = "GreaterThanOrEqualToThreshold" 
    evaluation_periods = "2" 
    ... etc 
} 

你如何重寫service變量comparison_operator和evaluation_periods你的模塊？

E.g.將cpu_max設置爲4是否與模塊中的aws_cloudwatch_metric_alarm .cpu_max.evaluation_periods = 4一樣簡單？

Answer 1

您必須使用具有默認值的variable。

variable "evaluation_periods" { 
    default = 4 
} 

resource "aws_cloudwatch_metric_alarm" "cpu_max" { 
    comparison_operator = "GreaterThanOrEqualToThreshold" 
    evaluation_periods = "${var.evaluation_periods}" 
} 

而且你的模塊

module "helloworld" { 
    source = ../service" 
    evaluation_periods = 2 
} 

Answer 2

你有你的模塊定義變量英寸你的模塊是：

variable "eval_period" {default = 2} # this becomes the input parameter of the module 

resource "aws_cloudwatch_metric_alarm" "cpu_max" { 
    comparison_operator = "GreaterThanOrEqualToThreshold" 
    evaluation_periods = "${var.eval_period}" 
    ... etc 
} 

，你會使用它像：

module "helloworld" { 
    source = ../service" 
    eval_period = 4 
}