JavaScript Azure Functions中process.env自定义键返回undefined问题

我正在将一个HTTP触发器函数部署到Azure Function，但尝试访问process.env中的条目时返回值为undefined。该逻辑在本地模拟器中运行正常，但部署到Azure后就无法正常工作。

我使用一个非常简单的HTTP函数进行了测试：

import { AzureFunction, Context, HttpRequest } from "@azure/functions";

const httpTrigger: AzureFunction = async function (
  context: Context,
  req: HttpRequest
): Promise<void> {
  context.log(process.env.GCP_SERVICE_ACCOUNT_EMAIL);

  context.res = {
    body: process.env.GCP_SERVICE_ACCOUNT_EMAIL,
  };
};

export default httpTrigger;

本地运行结果 #

本地运行时，会正常输出local.settings.json中设置的对应值：

[2021-09-11T13:41:27.737Z] Executing 'Functions.HttpTrigger' (Reason='This function was programmatically called via the host APIs.', Id=b9a303aa-5d14-403c-b841-4851f00beb65)
[2021-09-11T13:41:27.768Z] service_account@local.settings.json
[2021-09-11T13:41:27.848Z] Executed 'Functions.HttpTrigger' (Succeeded, Id=b9a303aa-5d14-403c-b841-4851f00beb65, Duration=126ms)

Azure端运行结果 #

但在Azure上运行时，输出为undefined（日志来自Azure门户单个函数的 监控 > 日志 页面）：

2021-09-11T13:26:40Z   [Information]   HTTP trigger function processed a request.
2021-09-11T13:26:40Z   [Information]   undefined

（我通过门户提供的URL触发函数，返回响应状态码为500）

Azure端打印完整process.env日志 #

我想确认是否影响了其他环境变量，因此尝试打印完整的process.env对象：

context.log(process.env)

可以看到输出中完全没有自定义的环境变量（部分敏感值已省略）：

2021-09-11T13:26:40Z   [Information]   HTTP trigger function processed a request.
2021-09-11T13:26:40Z   [Information]   { ServiceName: 'service',
  PWD: '/',
  Fabric_NetworkingMode: 'Other',
  Fabric_Id: '',
  ASPNETCORE_URLS: 'http://localhost:9091',
  AzureWebJobsScriptRoot: '/home/site/wwwroot',
  Fabric_ServiceName: 'service',
  CONTAINER_NAME: '',
  Fabric_Epoch: '',
  SUDO_UID: '0',
  Fabric_NodeIPOrFQDN: '',
  HOST_VERSION: '3.1.4.0',
  MESH_INIT_URI: '',
  DOTNET_USE_POLLING_FILE_WATCHER: 'true',
  SHLVL: '0',
  Fabric_ApplicationName: '',
  Fabric_CodePackageName: '',
  Fabric_ReplicaId: '',
  SUDO_COMMAND:
   '/azure-functions-host/Microsoft.Azure.WebJobs.Script.WebHost',
  Location: '',
  WEBSITE_HOME_STAMPNAME: '',
  ASPNETCORE_VERSION: '3.0.0',
  ResourceGroupName: '',
  TERM: 'xterm',
  languageWorkers__python__defaultRuntimeVersion: '3.6',
  HOME: '/home',
  LANG: 'C.UTF-8',
  Fabric_ServiceDnsName: '',
  LocalSitePackagesPath: '',
  CodePackageName: '',
  CONTAINER_IMAGE_URL: '',
  SubscriptionId:
   '',
  SUDO_GID: '0',
  WEBSITE_PLACEHOLDER_MODE: '1',
  CONTAINER_ENCRYPTION_KEY: '',
  ResourceName: '',
  ResourceType: '',
  WEBSITE_CLOUD_NAME: '',
  WEBSITE_STAMP_DEPLOYMENT_ID: '',
  USER: 'app',
  DOTNET_RUNNING_IN_CONTAINER: 'true',
  JAVA_HOME: '/usr/lib/jvm/zre-8-azure-amd64',
  SUDO_USER: 'root',
  SHELL: '/bin/bash',
  Fabric_ReplicaName: '0',
  HOSTNAME: '',
  PATH: '',
  CONTAINER_START_CONTEXT_SAS_URI: '',
  LOGNAME: 'app',
  _: '/usr/bin/setsid',
  FUNCTIONS_WORKER_DIRECTORY: '/azure-functions-host/workers/node' }

可以确认Function App门户的Configuration标签页中存在对应的配置条目：

同时在https://[function-app-name].scm.azurewebsites.net/api/settings地址下也能看到对应的键存在（敏感值已省略）：

{
  "deployment_branch": "master",
  "SCM_TRACE_LEVEL": "Verbose",
  "SCM_COMMAND_IDLE_TIMEOUT": "60",
  "SCM_LOGSTREAM_TIMEOUT": "7200",
  "SCM_BUILD_ARGS": "",
  "SCM_USE_LIBGIT2SHARP_REPOSITORY": "0",
  "APPINSIGHTS_INSTRUMENTATIONKEY": "",
  "AzureWebJobsDashboard": "",
  "AzureWebJobsStorage": "",
  "FUNCTIONS_EXTENSION_VERSION": "",
  "GCP_SERVICE_ACCOUNT_EMAIL": "",
  "GCP_SERVICE_ACCOUNT_PRIVATE_KEY": "",
  "LINE_NOTIFY_TOKEN": "",
  "WEBSITE_RUN_FROM_PACKAGE": "",
  "AzureWebJobs.TimerTrigger.Disabled": "",
  "ScmType": "",
  "WEBSITE_SITE_NAME": "",
  "WEBSITE_AUTH_ENABLED": "",
  "WEBSITE_SLOT_NAME": "",
  "SCM_RUN_FROM_PACKAGE": "",
  "REMOTEDEBUGGINGVERSION": "",
  "FUNCTIONS_RUNTIME_SCALE_MONITORING_ENABLED": "",
  "WEBSITE_AUTH_LOGOUT_PATH": "",
  "WEBSITE_AUTH_AUTO_AAD": "e"
}

我使用Terraform进行部署，配置参考公开的Azure Function Terraform部署示例，额外在app_settings中合并了环境变量配置：

variable "function_config" {
  type = map(string)
}

resource "azurerm_function_app" "function_app" {
  # 其余参数与标准示例配置一致

  app_settings = merge({
    "APPINSIGHTS_INSTRUMENTATIONKEY" = azurerm_application_insights.appInsights.instrumentation_key
    "WEBSITE_RUN_FROM_PACKAGE"       = ""
  }, var.function_config)
}

function_config = {
  LINE_NOTIFY_TOKEN               = ""
  GCP_SERVICE_ACCOUNT_PRIVATE_KEY = ""
  GCP_SERVICE_ACCOUNT_EMAIL       = ""
}

上述门户和Kudu中显示的所有环境变量值均由Terraform设置。

补充信息 #

最初我通过VSCode扩展创建了所有资源，之后使用上述配置将资源导入到Terraform状态中，部分资源在导入过程中被替换。

• 从门户重启Function App
• 删除所有函数后重新部署，部署前已删除dist文件夹确保仅部署新文件
• 通过修改Terraform中的名称强制重建App Service Plan和Function App，之后重新部署相同函数
• 将App Service Plan操作系统更换为Windows，结果相同
• 分别使用process.env.KEY和process.env["KEY"]两种方式访问环境变量

我不确定哪里出现了问题，也不知道接下来该尝试什么方案，恳请各位指点，谢谢！

更新说明 #

我尝试仅使用VSCode将函数部署到独立的资源组（资源不由Terraform创建），运行正常！因此可以确定是我的Terraform配置存在问题。接下来我会将我的Terraform配置与VSCode扩展自动生成的配置进行对比排查。

内容的提问来源于stack exchange，提问作者phwt