Disable automatic module upgrades for PowerShell 7.0 function apps (#956)

* Disable optional upgrades in PowerShell function apps (#779)

* Add AutomaticUpgradesAreDisabled message

* Disable optional upgrades

* Update test

* Update upgrade guidance for PowerShell 7.0 function apps

* Add installation directory for the .Net SDK

Author: Francisco-Gamino

src/DependencyManagement/BackgroundDependencySnapshotMaintainer.cs

@@ -20,6 +20,9 @@ internal class BackgroundDependencySnapshotMaintainer : IBackgroundDependencySna
         private TimeSpan MaxBackgroundUpgradePeriod { get; } =
             PowerShellWorkerConfiguration.GetTimeSpan("MDMaxBackgroundUpgradePeriod") ?? TimeSpan.FromDays(7);
 
+        private bool EnableAutomaticUpgrades { get; } =
+            PowerShellWorkerConfiguration.GetBoolean("MDEnableAutomaticUpgrades") ?? false;
+
         private readonly IDependencyManagerStorage _storage;
         private readonly IDependencySnapshotInstaller _installer;
         private readonly IDependencySnapshotPurger _purger;
@@ -42,6 +45,16 @@ public void Start(string currentSnapshotPath, DependencyManifestEntry[] dependen
 
             _purger.SetCurrentlyUsedSnapshot(currentSnapshotPath, logger);
 
+            if (!EnableAutomaticUpgrades)
+            {
+                logger.Log(
+                    isUserOnlyLog: false,
+                    RpcLog.Types.Level.Warning,
+                    PowerShellWorkerStrings.AutomaticUpgradesAreDisabled);
+
+                return;
+            }
+
             _installAndPurgeTimer = new Timer(
                                             _ => InstallAndPurgeSnapshots(PowerShell.Create, logger),
                                             state: null,

src/DependencyManagement/DependencyManager.cs

@@ -41,6 +41,9 @@ internal class DependencyManager : IDisposable
 
         private Task _dependencyInstallationTask;
 
+        private bool EnableAutomaticUpgrades { get; } =
+            PowerShellWorkerConfiguration.GetBoolean("MDEnableAutomaticUpgrades") ?? false;
+
         #endregion
 
         public DependencyManager(
@@ -199,6 +202,16 @@ internal Exception InstallFunctionAppDependencies(PowerShell firstPwsh, Func<Pow
                     RpcLog.Types.Level.Trace,
                     PowerShellWorkerStrings.AcceptableFunctionAppDependenciesAlreadyInstalled);
 
+                if (!EnableAutomaticUpgrades)
+                {
+                    logger.Log(
+                        isUserOnlyLog: false,
+                        RpcLog.Types.Level.Warning,
+                        PowerShellWorkerStrings.AutomaticUpgradesAreDisabled);
+
+                    return null;
+                }
+
                 // Background installation: can't use the firstPwsh runspace because it belongs
                 // to the pool used to run functions code, so create a new runspace.
                 _nextSnapshotPath = _backgroundSnapshotMaintainer.InstallAndPurgeSnapshots(pwshFactory, logger);

src/resources/PowerShellWorkerStrings.resx

@@ -352,4 +352,7 @@
   <data name="DependencySnapshotDoesNotContainAcceptableModuleVersions" xml:space="preserve">
     <value>Dependency snapshot '{0}' does not contain acceptable module versions.</value>
   </data>
+  <data name="AutomaticUpgradesAreDisabled" xml:space="preserve">
+    <value>Automatic upgrades are disabled in PowerShell 7.0 function apps. To enable this functionality back, please migrate your function app to PowerShell 7.2. For more details, see https://aka.ms/functions-powershell-7.0-to-7.2.</value>
+  </data>
 </root>

test/Unit/DependencyManagement/DependencyManagerTests.cs

@@ -163,40 +163,49 @@ public void StartDependencyInstallationIfNeeded_InstallsSnapshotInForeground_Whe
         [Fact]
         public void StartDependencyInstallationIfNeeded_InvokesBackgroundMaintainer_WhenAcceptableDependenciesAlreadyInstalled()
         {
-            _mockInstalledDependenciesLocator.Setup(_ => _.GetPathWithAcceptableDependencyVersionsInstalled())
-                .Returns("AlreadyInstalled");
-            _mockStorage.Setup(_ => _.GetDependencies()).Returns(GetAnyNonEmptyDependencyManifestEntries());
+            try
+            {
+                Environment.SetEnvironmentVariable("MDEnableAutomaticUpgrades", "true");
 
-            var firstPowerShellRunspace = PowerShell.Create();
-            Func<PowerShell> powerShellFactory = PowerShell.Create;
+                _mockInstalledDependenciesLocator.Setup(_ => _.GetPathWithAcceptableDependencyVersionsInstalled())
+                    .Returns("AlreadyInstalled");
+                _mockStorage.Setup(_ => _.GetDependencies()).Returns(GetAnyNonEmptyDependencyManifestEntries());
 
-            _mockStorage.Setup(_ => _.SnapshotExists("AlreadyInstalled")).Returns(true);
+                var firstPowerShellRunspace = PowerShell.Create();
+                Func<PowerShell> powerShellFactory = PowerShell.Create;
 
-            _mockBackgroundDependencySnapshotMaintainer.Setup(
-                _ => _.InstallAndPurgeSnapshots(It.IsAny<Func<PowerShell>>(), It.IsAny<ILogger>()))
-                .Returns("NewSnapshot");
+                _mockStorage.Setup(_ => _.SnapshotExists("AlreadyInstalled")).Returns(true);
 
-            using (var dependencyManager = CreateDependencyManagerWithMocks())
-            {
-                dependencyManager.Initialize(_mockLogger.Object);
-                dependencyManager.StartDependencyInstallationIfNeeded(firstPowerShellRunspace, powerShellFactory, _mockLogger.Object);
-                var hadToWait = dependencyManager.WaitForDependenciesAvailability(() => _mockLogger.Object);
+                _mockBackgroundDependencySnapshotMaintainer.Setup(
+                    _ => _.InstallAndPurgeSnapshots(It.IsAny<Func<PowerShell>>(), It.IsAny<ILogger>()))
+                    .Returns("NewSnapshot");
 
-                Assert.False(hadToWait);
-                Assert.Equal("NewSnapshot", dependencyManager.WaitForBackgroundDependencyInstallationTaskCompletion());
+                using (var dependencyManager = CreateDependencyManagerWithMocks())
+                {
+                    dependencyManager.Initialize(_mockLogger.Object);
+                    dependencyManager.StartDependencyInstallationIfNeeded(firstPowerShellRunspace, powerShellFactory, _mockLogger.Object);
+                    var hadToWait = dependencyManager.WaitForDependenciesAvailability(() => _mockLogger.Object);
 
-                _mockBackgroundDependencySnapshotMaintainer.Verify(
-                    _ => _.InstallAndPurgeSnapshots(powerShellFactory, _mockLogger.Object),
+                    Assert.False(hadToWait);
+                    Assert.Equal("NewSnapshot", dependencyManager.WaitForBackgroundDependencyInstallationTaskCompletion());
+
+                    _mockBackgroundDependencySnapshotMaintainer.Verify(
+                        _ => _.InstallAndPurgeSnapshots(powerShellFactory, _mockLogger.Object),
+                        Times.Once);
+                }
+
+                _mockLogger.Verify(
+                    _ => _.Log(
+                        false,
+                        LogLevel.Trace,
+                        It.Is<string>(message => message.Contains(PowerShellWorkerStrings.AcceptableFunctionAppDependenciesAlreadyInstalled)),
+                        It.IsAny<Exception>()),
                     Times.Once);
             }
-
-            _mockLogger.Verify(
-                _ => _.Log(
-                    false,
-                    LogLevel.Trace,
-                    It.Is<string>(message => message.Contains(PowerShellWorkerStrings.AcceptableFunctionAppDependenciesAlreadyInstalled)),
-                    It.IsAny<Exception>()),
-                Times.Once);
+            finally
+            {
+                Environment.SetEnvironmentVariable("MDEnableAutomaticUpgrades", null);
+            }
         }
 
         [Fact]

tools/helper.psm1

@@ -74,9 +74,9 @@ function Install-Dotnet {
             $version = "$majorMinorVersion.$($DotnetSDKVersionRequirements[$majorMinorVersion].DefaultPatch)"
             Write-Log "Installing dotnet SDK version $version" -Warning
             if ($IsWindowsEnv) {
-                & .\$installScript -Channel $Channel -Version $Version
+                & .\$installScript -Channel $Channel -Version $Version -InstallDir "$env:ProgramFiles/dotnet"
             } else {
-                bash ./$installScript -c $Channel -v $Version
+                bash ./$installScript -c $Channel -v $Version --install-dir /usr/share/dotnet
             }
         }