Improve publish error message when public network access is disabled

release_notes.md

@@ -24,4 +24,5 @@
   - Support for custom bundle download paths via `AzureFunctionsJobHost__extensionBundle__downloadPath` environment variable
 - Added `--bundles-channel` option to `func init` command to specify extension bundle channel (GA, Preview, or Experimental) during project initialization
 - Fallback to cached bundles if there is no network connection during `func start` (#4772)
-  - Added global `--offline` variable to run in offline mode (#4772)
+- Added global `--offline` variable to run in offline mode (#4772)
+- Improved error message for `func azure functionapp publish` when the connection fails due to networking restrictions, with a link to networking options documentation. (#4807)

src/Cli/func/Actions/AzureActions/PublishFunctionAppAction.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT License. See LICENSE in the project root for license information.
 
 using System.Globalization;
+using System.Net.Http;
 using System.Net.Http.Handlers;
 using System.Net.Http.Headers;
 using Azure.Functions.Cli.Actions.LocalActions;
@@ -240,13 +241,22 @@ public override async Task RunAsync()
             }
             else
             {
-                if (PublishLocalSettingsOnly)
+                try
                 {
-                    await PublishLocalAppSettings(functionApp, additionalAppSettings);
+                    if (PublishLocalSettingsOnly)
+                    {
+                        await PublishLocalAppSettings(functionApp, additionalAppSettings);
+                    }
+                    else
+                    {
+                        await PublishFunctionApp(functionApp, ignoreParser, additionalAppSettings);
+                    }
                 }
-                else
+                catch (HttpRequestException ex)
                 {
-                    await PublishFunctionApp(functionApp, ignoreParser, additionalAppSettings);
+                    // HttpRequestException is thrown for connectivity failures (SSL, socket, DNS)
+                    // not for HTTP status errors, which are handled by CheckResponseStatusAsync as CliException.
+                    throw new CliException($"{Constants.Errors.PublishNetworkingError}{Environment.NewLine}Details: {ex.Message}", ex);
                 }
             }
         }

src/Cli/func/Common/Constants.cs

@@ -143,6 +143,7 @@ public static class Errors
             public const string EitherPidOrAllMustBeSpecified = "Must specify either -a/--all or -p/--processId <Pid>";
             public const string ExtensionsNeedDotnet = "Extensions command requires dotnet on your path. Please make sure to install dotnet (.NET Core SDK) for your system from https://www.microsoft.com/net/download";
             public const string UnableToUpdateAppSettings = "Error updating Application Settings for the Function App for deployment.";
+            public const string PublishNetworkingError = "Unable to connect to the Azure Function App. If public network access is disabled for this app, ensure you are deploying from an authorized network. For more information, see https://learn.microsoft.com/azure/azure-functions/functions-networking-options";
             public const string WebJobsStorageNotFound = "Missing value for AzureWebJobsStorage in {0}. This is required for all triggers other than {1}. You can run 'func azure functionapp fetch-app-settings <functionAppName>' or specify a connection string in {2}.";
             public const string WebJobsStorageNotFoundWithUserSecrets = "Missing value for AzureWebJobsStorage in {0} and User Secrets. This is required for all triggers other than {1}. You can run 'func azure functionapp fetch-app-settings <functionAppName>' or specify a connection string in {2} or User Secrets.";
             public const string AppSettingNotFound = "Warning: Cannot find value named '{0}' in {1} that matches '{2}' property set on '{3}' in '{4}'. You can run 'func azure functionapp fetch-app-settings <functionAppName>' or specify a connection string in {5}.";