Azure 原則模式：效果

Azure 原則有許多效果，可決定服務如何回應不符合規範的資源。 有些效果很簡單，不需要原則定義中的其他屬性，而有些則需要數個屬性。

範例 1：簡單效果

此原則定義會檢查 tagName 參數中定義的標記是否存在於已評估的資源上。 如果標記尚不存在，則會觸發 modify 效果，使用 tagValue 參數中的值新增標記。

{
    "properties": {
        "displayName": "Add a tag to resource groups",
        "policyType": "BuiltIn",
        "mode": "All",
        "description": "Adds the specified tag and value when any resource group missing this tag is created or updated. Existing resource groups can be remediated by triggering a remediation task. If the tag exists with a different value it will not be changed.",
        "metadata": {
            "version": "1.0.0",
            "category": "Tags"
        },
        "parameters": {
            "tagName": {
                "type": "String",
                "metadata": {
                    "displayName": "Tag Name",
                    "description": "Name of the tag, such as 'environment'"
                }
            },
            "tagValue": {
                "type": "String",
                "metadata": {
                    "displayName": "Tag Value",
                    "description": "Value of the tag, such as 'production'"
                }
            }
        },
        "policyRule": {
            "if": {
                "allOf": [{
                        "field": "type",
                        "equals": "Microsoft.Resources/subscriptions/resourceGroups"
                    },
                    {
                        "field": "[concat('tags[', parameters('tagName'), ']')]",
                        "exists": "false"
                    }
                ]
            },
            "then": {
                "effect": "modify",
                "details": {
                    "roleDefinitionIds": [
                        "/providers/microsoft.authorization/roleDefinitions/b24988ac-6180-42a0-ab88-20f7382dd24c"
                    ],
                    "operations": [{
                        "operation": "add",
                        "field": "[concat('tags[', parameters('tagName'), ']')]",
                        "value": "[parameters('tagValue')]"
                    }]
                }
            }
        }
    }
}

範例 1：說明

"effect": "modify",
"details": {
    "roleDefinitionIds": [
        "/providers/microsoft.authorization/roleDefinitions/b24988ac-6180-42a0-ab88-20f7382dd24c"
    ],
    "operations": [{
        "operation": "add",
        "field": "[concat('tags[', parameters('tagName'), ']')]",
        "value": "[parameters('tagValue')]"
    }]
}

modify 效果需要 policyRule.then.details 區塊，以定義 roleDefinitionIds 和 operations。 這些參數會告知 Azure 原則需要哪些角色才能新增標籤並補救資源，以及要執行哪個 modify 作業。 在此範例中，會使用新增作業和參數來設定標籤和其值。

範例 2：複雜效果

此原則定義會在延伸模組不存在時稽核每個虛擬機器，延伸模組會在 publisher 和 type 參數中定義。 其使用 auditIfNotExists 來檢查與虛擬機器相關的資源，以查看是否有執行個體符合定義的參數。 此範例會檢查延伸模組類型。

{
    "type": "Microsoft.Authorization/policyDefinitions",
    "name": "audit-vm-extension",
    "properties": {
        "displayName": "Audit if extension does not exist",
        "description": "This policy audits if a required extension doesn't exist.",
        "parameters": {
            "publisher": {
                "type": "String",
                "metadata": {
                    "description": "The publisher of the extension",
                    "displayName": "Extension Publisher"
                }
            },
            "type": {
                "type": "String",
                "metadata": {
                    "description": "The type of the extension",
                    "displayName": "Extension Type"
                }
            }
        },
        "policyRule": {
            "if": {
                "allOf": [{
                        "field": "type",
                        "equals": "Microsoft.Compute/virtualMachines"
                    },
                    {
                        "field": "Microsoft.Compute/imagePublisher",
                        "in": [
                            "MicrosoftWindowsServer"
                        ]
                    },
                    {
                        "field": "Microsoft.Compute/imageOffer",
                        "in": [
                            "WindowsServer"
                        ]
                    }
                ]
            },
            "then": {
                "effect": "auditIfNotExists",
                "details": {
                    "type": "Microsoft.Compute/virtualMachines/extensions",
                    "existenceCondition": {
                        "allOf": [{
                                "field": "Microsoft.Compute/virtualMachines/extensions/publisher",
                                "equals": "[parameters('publisher')]"
                            },
                            {
                                "field": "Microsoft.Compute/virtualMachines/extensions/type",
                                "equals": "[parameters('type')]"
                            }
                        ]
                    }
                }
            }
        }
    }
}

範例 2：說明

"details": {
    "type": "Microsoft.Compute/virtualMachines/extensions",
    "existenceCondition": {
        "allOf": [{
                "field": "Microsoft.Compute/virtualMachines/extensions/publisher",
                "equals": "[parameters('publisher')]"
            },
            {
                "field": "Microsoft.Compute/virtualMachines/extensions/type",
                "equals": "[parameters('type')]"
            }
        ]
    }
}

auditIfNotExists 效果需要 policyRule.then.details 區塊，以定義要尋找的 type 和 existenceCondition。 existenceCondition 會使用原則語言元素 (例如邏輯運算子) 來判斷相符的相關資源是否存在。 在此範例中，針對每個別名檢查的值會定義在參數中。

下一步

• 檢閱其他模式和內建定義。
• 檢閱 Azure 原則定義結構。
• 檢閱了解原則效果。