对空资源本地执行使用时间戳

Question

我只想每小时执行一次 exec 操作。意思是，如果现在是 12 点，那么在 13 点之前不要再次执行。

时间戳与 fomatdate 相结合将产生仅每小时不同的时间戳。

resource "null_resource" "helm_login" {
  triggers = {
    hour = formatdate("YYYYMMDDhh", timestamp())
  }
  provisioner "local-exec" {
    command = <<-EOF
      az acr login -n ${var.helm_chart_acr_fqdn} -t -o tsv --query accessToken \
        | helm registry login ${var.helm_chart_acr_fqdn} \
          -u "00000000-0000-0000-0000-000000000000" \
          --password-stdin
    EOF
  }

问题是 terraform 报告说这个值只有在 appy 之后才知道，并且总是想重新创建资源。

  # module.k8s.null_resource.helm_login must be replaced
-/+ resource "null_resource" "helm_login" {
      ~ id       = "4503742218368236410" -> (known after apply)
      ~ triggers = {
          - "hour" = "2021112010"
        } -> (known after apply) # forces replacement
    }

我观察到类似的问题，即从数据中获取值并在创建时传递给资源，这迫使我不使用这些数据值，而是对它们进行硬编码。

Answer 1

正如您刚刚发现 terraform 在运行时评估时间戳功能，
这就是为什么我们看到： (known after apply) # forces replacement

但是我们可以为此做一些事情来实现您的目标，我们可以将小时作为参数传递：

variable "hour" {
  type = number
}

resource "null_resource" "test" {
  triggers = {
    hour = var.hour
  }
  provisioner "local-exec" {
    command = "echo 'test'"
  }
}

然后调用 terraform 我们这样做：
hour=$(date +%G%m%d%H); sudo terraform apply -var="hour=$hour"

---

第一次运行：

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
  + create

Terraform will perform the following actions:

  # null_resource.test will be created
  + resource "null_resource" "test" {
      + id       = (known after apply)
      + triggers = {
          + "hour" = "2021112011"
        }
    }

Plan: 1 to add, 0 to change, 0 to destroy.

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

null_resource.test: Creating...
null_resource.test: Provisioning with 'local-exec'...
null_resource.test (local-exec): Executing: ["/bin/sh" "-c" "echo 'test'"]
null_resource.test (local-exec): test
null_resource.test: Creation complete after 0s [id=6793564729560967989]

第二次运行：

null_resource.test: Refreshing state... [id=6793564729560967989]

Apply complete! Resources: 0 added, 0 changed, 0 destroyed.