FileSystemReadOnly when functions running in ACA environment (#11338)

* FileSystemReadOnly when functions running in ACA environment

* add UT

* minor change

* revert minor change

---------

Co-authored-by: Krishna Jaju <[email protected]>

Author: krishnajaju

src/WebJobs.Script.WebHost/Configuration/ScriptApplicationHostOptionsSetup.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 using System;
@@ -80,6 +80,13 @@ private bool IsZipDeployment(out bool isScmRunFromPackage)
                 return true;
             }
 
+            // Functions on Container Apps always have a read-only filesystem
+            if (_environment.IsManagedAppEnvironment())
+            {
+                isScmRunFromPackage = false;
+                return true;
+            }
+
             // Check app settings for run from package.
             bool runFromPkgConfigured = Utility.IsValidZipSetting(_environment.GetEnvironmentVariable(AzureWebsiteZipDeployment)) ||
                 Utility.IsValidZipSetting(_environment.GetEnvironmentVariable(AzureWebsiteAltZipDeployment)) ||

src/WebJobs.Script/Environment/EnvironmentExtensions.cs

@@ -305,7 +305,7 @@ public static bool IsAnyKubernetesEnvironment(this IEnvironment environment)
         }
 
         /// <summary>
-        /// Gets a value indicating whether the application is running in Managed App environment.
+        /// Gets a value indicating whether the application is running in Managed App environment (Azure Container Apps environment).
         /// </summary>
         /// <param name="environment">The environment to verify.</param>
         /// <returns><see cref="true"/> if running in Managed App environment; otherwise, false.</returns>

test/WebJobs.Script.Tests/Configuration/ScriptApplicationHostOptionsSetupTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the MIT License. See License.txt in the project root for license information.
 
 using System;
@@ -113,6 +113,18 @@ public void IsFileSystemReadOnly_AlwaysAppliesForFlex()
             Assert.Equal(options.IsFileSystemReadOnly, true);
         }
 
+        [Fact]
+        public void IsFileSystemReadOnly_AlwaysAppliesForContainerAppsEnvironment()
+        {
+            var environment = new TestEnvironment();
+            environment.SetEnvironmentVariable(EnvironmentSettingNames.ManagedEnvironment, "true");
+
+            ScriptApplicationHostOptions options = new ScriptApplicationHostOptions();
+            ConfiguredOptions(options, inStandbyMode: false, environment);
+
+            Assert.Equal(options.IsFileSystemReadOnly, true);
+        }
+
         private void ConfiguredOptions(ScriptApplicationHostOptions options, bool inStandbyMode, IEnvironment environment = null, bool blobExists = false)
         {
             var builder = new ConfigurationBuilder();