azure - Terraform 强制替换 AKS 节点池而不进行任何更改

Question

我的 k8s 集群中的其他节点池有以下资源定义:

resource "azurerm_kubernetes_cluster_node_pool" "extra" {
  for_each = var.node_pools

  kubernetes_cluster_id   = azurerm_kubernetes_cluster.k8s.id
  name                    = each.key
  vm_size                 = each.value["vm_size"]
  node_count              = each.value["count"]
  node_labels             = each.value["labels"]
  vnet_subnet_id          = var.subnet.id
}

这是terraform plan的输出:

Note: Objects have changed outside of Terraform

Terraform detected the following changes made outside of Terraform since the last "terraform apply":

  # module.aks.azurerm_kubernetes_cluster_node_pool.extra["general"] has been changed
  ~ resource "azurerm_kubernetes_cluster_node_pool" "extra" {
      + availability_zones     = []
        id                     = "/subscriptions/3913c9fe-c571-4af9-bc9a-533202d41061/resourcegroups/amic-resources/providers/Microsoft.ContainerService/managedClusters/amic-k8s-01/agentPools/general"
        name                   = "general"
      + node_taints            = []
      + tags                   = {}
        # (18 unchanged attributes hidden)
    }

Unless you have made equivalent changes to your configuration, or ignored the relevant attributes using ignore_changes, the following plan may include actions to undo or respond to these changes.

──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────

Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with the following symbols:
-/+ destroy and then create replacement

Terraform will perform the following actions:

  # module.aks.azurerm_kubernetes_cluster_node_pool.extra["general"] must be replaced
-/+ resource "azurerm_kubernetes_cluster_node_pool" "extra" {
      - availability_zones     = [] -> null
      - enable_auto_scaling    = false -> null
      - enable_host_encryption = false -> null
      - enable_node_public_ip  = false -> null
      ~ id                     = "/subscriptions/3913c9fe-c571-4af9-bc9a-533202d41061/resourcegroups/amic-resources/providers/Microsoft.ContainerService/managedClusters/amic-k8s-01/agentPools/general" -> (known after apply)
      ~ kubernetes_cluster_id  = "/subscriptions/3913c9fe-c571-4af9-bc9a-533202d41061/resourcegroups/amic-resources/providers/Microsoft.ContainerService/managedClusters/amic-k8s-01" -> "/subscriptions/3913c9fe-c571-4af9-bc9a-533202d41061/resourceGroups/amic-resources/providers/Microsoft.ContainerService/managedClusters/amic-k8s-01" # forces replacement
      - max_count              = 0 -> null
      ~ max_pods               = 30 -> (known after apply)
      - min_count              = 0 -> null
        name                   = "general"
      - node_taints            = [] -> null
      ~ orchestrator_version   = "1.20.7" -> (known after apply)
      ~ os_disk_size_gb        = 128 -> (known after apply)
      - tags                   = {} -> null
        # (9 unchanged attributes hidden)
    }

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

如您所见，由于 kubernetes_cluster_id 发生更改，terraform 尝试强制替换我的节点池，即使该值实际上根本没有任何变化。我已经能够通过忽略 lifecycle block 中的 kubernetes_cluster_id 更改来解决此问题，但我仍然对为什么 terraform 检测到那里的更改感到困惑。

那么为什么 Terraform 在这种情况下发现了变化，而没有变化呢？

Answer 1

我并不自豪，但我设法通过使用“replace ” terraform 字符串函数解决了这个错误。

resource "azurerm_kubernetes_cluster_node_pool" "extra" {
  [...]
  # Use this once the bug gets fixed in the provider, and delete the workaround.
  # kubernetes_cluster_id   = azurerm_kubernetes_cluster.k8s.id 
  kubernetes_cluster_id   = replace(azurerm_kubernetes_cluster.k8s.id, "resourceGroups", "resourcegroups")

  [...]
}

注意:我不会将 /resourceGroups/ 替换为 /resourcegroups/，因为 replace 函数将默认认为这是一个正则表达式替换，这可能最终会重复你的正斜杠。 (我自己没有测试过)