Loop场景下Bicep模块如何处理父资源引用及订阅创建依赖

问题 #

通过循环创建Azure Service Bus的Topic和Subscription时，偶尔会执行失败，报错显示在Topic未创建完成的情况下就尝试创建Subscription，重新运行管道则可正常执行。报错信息如下：

The incoming request is not recognized as a namespace policy put request. ttps://aka.ms/sbResourceMgrExceptions. TrackingId:e1d2c50d-fe92-43d8-abfe-8eb2c1917a70_G5, SystemTracker:ihdev-nonprod-servicebus.servicebus.windows.net:dev-sb-topic-test/subscriptions/dev-sb-sub-test, Timestamp:2024-04-08T13:33:29 (Code: MessagingGatewayNotFoundStatusCode

推测问题源于未正确设置资源依赖关系，希望明确如何让特定Subscription仅在对应Topic创建完成后再启动创建流程，不确定是否需要将循环从for topic in topicsAndSubscriptions改为for (topic, i) in topicsAndSubscriptions来添加dependsOn[i]。

相关代码 #

Main.bicepparam

using './main.biceicep'

param serviceBusNamespaceName = '#{SBUS_NAMESPACE_NAME}#'
param topicsAndSubscriptions = [
  {
    name: 'dev-sb-top-failure'
    subscriptions: [
      'dev-sb-sub-failure'
    ]
  }
  {
    name: 'xrm-dev-sb-report-completion'
    subscriptions: [
      'dev-sb-sub-report-completion'
    ]
  }
  {
    name: 'dev-sb-top-completion'
    subscriptions: [
      'dev-sb-sub-completion'
    ]
  }
  {
    name: 'dev-sb-top-discharge'
    subscriptions: [
      'dev-sb-sub-discharge'
    ]
  }
]

main.bicep

@description('Name of the Service Bus namespace')
param serviceBusNamespaceName string

@description('Location for all resources.')
param location string = resourceGroup().location
param topicsAndSubscriptions array

resource serviceBusNamespace 'Microsoft.ServiceBus/namespaces@2022-01-01-preview' = {
  name: serviceBusNamespaceName
  location: location
  sku: {
    name: 'Premium'
  }
  properties: {}
}

resource serviceBusTopic 'Microsoft.ServiceBus/namespaces/topics@2022-10-01-preview' = [
  for topic in topicsAndSubscriptions: {
    parent: serviceBusNamespace
    name: topic.name
    properties: {}
  }
]

module subs 'modules/subscription.bicep' = [
  for topic in topicsAndSubscriptions: {
    name: '${topic.name}-subs'
    params: {
      servicebusNamespaceName: serviceBusNamespaceName
      topicName: topic.name
      subscriptions: topic.subscriptions
    }
  }
]

subscription.bicep（模块文件）

param servicebusNamespaceName string
param topicName string
param subscriptions array = ['asubscription', 'anotherone']

resource sub 'Microsoft.ServiceBus/namespaces/topics/subscriptions@2022-10-01-preview' = [
  for i in subscriptions: {
    name: '${servicebusNamespaceName}/${topicName}/${i}'
    properties: {}
  }
]

解决方案 #

1. 为Subscription模块添加对应Topic的强依赖 #

在main.bicep中，将模块循环改为带索引的形式，明确指定每个Subscription模块依赖于对应索引的Topic资源，确保Topic创建完成后再启动Subscription的创建：

修改后的main.bicep模块部分：

module subs 'modules/subscription.bicep' = [
  for (topic, i) in topicsAndSubscriptions: {
    name: '${topic.name}-subs'
    params: {
      servicebusNamespaceName: serviceBusNamespaceName
      topicName: topic.name
      subscriptions: topic.subscriptions
    }
    // 绑定对应索引的Topic资源作为依赖
    dependsOn: [
      serviceBusTopic[i]
    ]
  }
]

2. 优化Subscription模块的资源定义（可选但推荐） #

在subscription.bicep中，避免手动拼接资源全名，改用parent属性关联对应Topic，让Bicep自动识别资源层级关系，同时提升代码可读性：

修改后的subscription.bicep：

param serviceBusNamespaceName string
param topicName string
param subscriptions array = ['asubscription', 'anotherone']

// 引用已创建的Topic作为父资源
resource targetTopic 'Microsoft.ServiceBus/namespaces/topics@2022-10-01-preview' existing = {
  parent: resource('Microsoft.ServiceBus/namespaces@2022-01-01-preview', serviceBusNamespaceName)
  name: topicName
}

resource sub 'Microsoft.ServiceBus/namespaces/topics/subscriptions@2022-10-01-preview' = [
  for subName in subscriptions: {
    parent: targetTopic
    name: subName
    properties: {}
  }
]

此优化无需修改main.bicep的参数传递，仅需保留第一步的dependsOn配置即可。

内容的提问来源于stack exchange，提问作者h00jraq