Fix accidental VMApp removal when extension update fails. Also migrate VMApp download directory on extension update.

.gitignore

@@ -13,3 +13,5 @@ bundle
 extension-launcher*
 internal/customactionplan/testdir/
 licenses
+main.exe
+internal/hostgacommunicator/TestArtifacts/

Makefile

@@ -2,7 +2,6 @@ BUNDLEDIR=bundle/linux/prod
 BUNDLEDIR_TEST=bundle/linux/test
 BINDIR=$(BUNDLEDIR)/bin
 BINDIR_TEST=$(BUNDLEDIR_TEST)/bin
-EXTENSIONVERSION=1.0.18
 ALLOWED_EXT1=Microsoft.CPlat.Core.VMApplicationManagerLinux
 ALLOWED_EXT2=Microsoft.CPlat.Core.EDP.VMApplicationManagerLinux
 
@@ -20,20 +19,20 @@ clean:
 	-rm -Rf $(BUNDLEDIR_TEST)
 	-rm -Rf licenses
 
-extension-launcher: validate-extension-name
+extension-launcher: validate-extension-name validate-extension-version
 	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o extension-launcher -ldflags="-X 'main.ExtensionName=$(EXTENSIONNAME)' -X 'main.ExtensionVersion=$(EXTENSIONVERSION)' -X 'main.ExecutableName=vm-application-manager'" ./launcher
 
-extension-launcher-arm64: validate-extension-name
+extension-launcher-arm64: validate-extension-name validate-extension-version
 	GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go build -o extension-launcher-arm64 -ldflags="-X 'main.ExtensionName=$(EXTENSIONNAME)' -X 'main.ExtensionVersion=$(EXTENSIONVERSION)' -X 'main.ExecutableName=vm-application-manager'" ./launcher # For ARM64 machines, install command will rename vm-application-manager-arm64 to vm-application-manager
 
-vm-application-manager: validate-extension-name
+vm-application-manager: validate-extension-name validate-extension-version
 	GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -o  vm-application-manager -ldflags="-X 'main.ExtensionName=$(EXTENSIONNAME)' -X 'main.ExtensionVersion=$(EXTENSIONVERSION)'" ./main
 
-vm-application-manager-arm64: validate-extension-name
+vm-application-manager-arm64: validate-extension-name validate-extension-version
 	GOOS=linux GOARCH=arm64 CGO_ENABLED=0 go build -o vm-application-manager-arm64 -ldflags="-X 'main.ExtensionName=$(EXTENSIONNAME)' -X 'main.ExtensionVersion=$(EXTENSIONVERSION)'"  ./main
 
 
-.PHONY: validate-extension-name
+.PHONY: validate-extension-name validate-extension-version
 validate-extension-name:
 	@case "$(EXTENSIONNAME)" in \
 	  "$(ALLOWED_EXT1)"|"$(ALLOWED_EXT2)" ) ;; \
@@ -44,15 +43,27 @@ validate-extension-name:
 	       exit 1 ;; \
 	esac
 
+validate-extension-version:
+	@if [ -z "$(EXTENSIONVERSION)" ]; then \
+		echo "Error: EXTENSIONVERSION parameter is required"; \
+		echo "Usage: make EXTENSIONVERSION=<version>"; \
+		exit 1; \
+	fi
+	@echo "$(EXTENSIONVERSION)" | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+$$' || { \
+		echo "Error: EXTENSIONVERSION '$(EXTENSIONVERSION)' does not match required pattern n.n.n (e.g., 1.0.18)"; \
+		exit 1; \
+	}
+	@echo "Using EXTENSIONVERSION: $(EXTENSIONVERSION)"
+
 collect-licenses:
 	@echo "Collecting open source licenses..."
 	@if [ ! -f "$$(go env GOPATH)/bin/go-licenses" ]; then \
 		echo "Installing go-licenses..."; \
 		go install github.com/google/go-licenses@latest; \
 	fi
 	mkdir -p licenses/reports
-	$$(go env GOPATH)/bin/go-licenses save ./main --save_path=licenses/texts
-	$$(go env GOPATH)/bin/go-licenses csv ./main > licenses/reports/THIRD_PARTY_LICENSES.csv
+	-$$(go env GOPATH)/bin/go-licenses save ./main --save_path=licenses/texts --ignore=std --ignore=golang.org/x/sys
+	-$$(go env GOPATH)/bin/go-licenses csv ./main --ignore=std --ignore=golang.org/x/sys > licenses/reports/THIRD_PARTY_LICENSES.csv
 	@echo "License collection complete!"
 
 bundle-prod: extension-launcher extension-launcher-arm64 vm-application-manager vm-application-manager-arm64
@@ -70,7 +81,7 @@ bundle-prod: extension-launcher extension-launcher-arm64 vm-application-manager
 
 bundle-test:
 	@echo "Building and packaging TEST bundle into $(BUNDLEDIR_TEST) with EXTENSIONNAME=$(ALLOWED_EXT2)"
-	$(MAKE) EXTENSIONNAME=$(ALLOWED_EXT2) extension-launcher extension-launcher-arm64 vm-application-manager vm-application-manager-arm64
+	$(MAKE) EXTENSIONNAME=$(ALLOWED_EXT2) EXTENSIONVERSION=$(EXTENSIONVERSION) extension-launcher extension-launcher-arm64 vm-application-manager vm-application-manager-arm64
 	mkdir -p $(BINDIR_TEST)
 	mv extension-launcher "$(BINDIR_TEST)/"
 	mv extension-launcher-arm64 "$(BINDIR_TEST)/"

README.md

@@ -32,9 +32,9 @@ Trademarks This project may contain trademarks or logos for projects, products,
     -  OS-specific tests may be run on an Azure VM or local VM (eg. WSL on Windows)
 -  To build the extension zip packages
     - Windows:
-        - execute `nmake -f makefile.win`
+        - execute `nmake -f makefile.win EXTENSIONVERSION=<n.n.n>`
     - Linux:
-        - execute `make`
+        - execute `make EXTENSIONVERSION=<n.n.n>`
 
 -  Please do not check-in vendor files
 

go.mod

@@ -5,7 +5,7 @@ go 1.24.0
 toolchain go1.24.3
 
 require (
-	github.com/Azure/azure-extension-platform v0.0.0-20250107200156-aa20f765d49f
+	github.com/Azure/azure-extension-platform v0.0.0-20260406194436-44ca1f420dd8
 	github.com/ahmetalpbalkan/go-httpbin v0.0.0-20200921172446-862fbad56b77
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.7.0

go.sum

@@ -1,5 +1,5 @@
-github.com/Azure/azure-extension-platform v0.0.0-20250107200156-aa20f765d49f h1:ddsUz/suc9txCMz/xWOslqNMvzhbWFMTflUrbcMNoSw=
-github.com/Azure/azure-extension-platform v0.0.0-20250107200156-aa20f765d49f/go.mod h1:0458BvQsi5ch6kn+KZtI5m88Z3L9UFXdoY1+6nKdivY=
+github.com/Azure/azure-extension-platform v0.0.0-20260406194436-44ca1f420dd8 h1:MwcGMMMhzVioChv9aIe5pbl85WiQuWaR9t+sdZpK3/U=
+github.com/Azure/azure-extension-platform v0.0.0-20260406194436-44ca1f420dd8/go.mod h1:0458BvQsi5ch6kn+KZtI5m88Z3L9UFXdoY1+6nKdivY=
 github.com/ahmetalpbalkan/go-httpbin v0.0.0-20200921172446-862fbad56b77 h1:QLWeOzO9GTjP14jyM0g7IHhYbnWWR3Wi4kipv3iDOJY=
 github.com/ahmetalpbalkan/go-httpbin v0.0.0-20200921172446-862fbad56b77/go.mod h1:Rg55S63lgqSBCawY/oTm7jdFSySp6jwIqgHMB2IeHK8=
 github.com/ahmetb/go-httpbin v0.0.0-20200921172446-862fbad56b77 h1:tLnVshegsavDh3VnYwLVgYe7i5/O61LrhKGU+cTR95E=

internal/packageregistry/packageregistry.go

@@ -5,7 +5,6 @@ package packageregistry
 
 import (
 	"encoding/json"
-	"io/ioutil"
 	"os"
 	"path"
 	"time"
@@ -168,7 +167,7 @@ func (self *PackageRegistry) GetExistingPackages() (CurrentPackageRegistry, erro
 	_, err := os.Stat(localApplicationRegistryFilePath)
 	if err == nil {
 		// The file exists
-		fileBytes, err := ioutil.ReadFile(localApplicationRegistryFilePath)
+		fileBytes, err := os.ReadFile(localApplicationRegistryFilePath)
 		if err != nil {
 			return currentPackageRegistry, err
 		}
@@ -210,7 +209,7 @@ func (self *PackageRegistry) WriteToDisk(packageRegistry CurrentPackageRegistry)
 		return err
 	}
 
-	err = ioutil.WriteFile(regFile, bytes, constants.FilePermissions_UserOnly_ReadWrite)
+	err = os.WriteFile(regFile, bytes, constants.FilePermissions_UserOnly_ReadWrite)
 	self.logger.Info("Wrote package registry to %v", regFile)
 
 	if doesBackupFileExist {

launcher/main.go

@@ -49,6 +49,13 @@ func main() {
 		eh.Exit(exithelper.MiscError)
 	}
 
+	// validate ExtensionVersion against the version reported by Guest Agent
+	if extensionVersionFromEnv, err := vmextension.GetGuestAgentEnvironmetVariable(vmextension.GuestAgentEnvVarExtensionVersion); err == nil {
+		if extensionVersionFromEnv != ExtensionVersion {
+			el.Warn("ExtensionVersion mismatch: compile-time ExtensionVersion value '%s' does not match value '%s' in environment variable '%s'", ExtensionVersion, extensionVersionFromEnv, vmextension.GuestAgentEnvVarExtensionVersion)
+		}
+	}
+
 	arg := args[1]
 
 	switch arg {

main/main.go

@@ -25,19 +25,16 @@ import (
 )
 
 var (
-	ExtensionName         string     // assign at compile time
-	ExtensionVersion      = "1.0.10" // should be assigned at compile time, do not edit in code
+	ExtensionName         string     // assign at compile time, it is the ExtensionPublisher.ExtensionType
+	ExtensionVersion      = "1.0.10" // should be assigned at compile time, do not edit in code outside of unit tests
 	reportStatusFunc      = utils.ReportStatus
 	getVMExtensionFunc    = getVMExtension
 	customEnableFunc      = customEnable
 	setSequenceNumberFunc = seqno.SetSequenceNumber
 )
 
 const (
-	vmPackagesSetting       = "vmPackages"
-	operationInstall        = "install"
-	operationUpdate         = "update"
-	operationRemove         = "remove"
+	argVersion              = "version"
 	filelockTimeoutDuration = 45 * time.Minute
 )
 
@@ -49,19 +46,43 @@ func main() {
 }
 
 func getExtensionAndRun(arguments []string) error {
+	if len(arguments) == 2 && strings.EqualFold(arguments[1], argVersion) {
+		fmt.Println("Extension version is", ExtensionVersion)
+		return nil
+	}
+
 	// require SeqNoChange is set to false because we want the extension to ensure that the packages are in sync with the desired packages
 	ext, err := getVMExtensionFunc()
 	if err != nil {
 		return err
 	}
 
+	// validate ExtensionVersion against the version reported by Guest Agent
+	if extVersionInEnvVariable, err := vmextensionhelper.GetGuestAgentEnvironmetVariable(vmextensionhelper.GuestAgentEnvVarExtensionVersion); err == nil {
+		if extVersionInEnvVariable != ExtensionVersion {
+			msg := fmt.Sprintf("ExtensionVersion mismatch: compile-time ExtensionVersion value '%s' does not match value '%s' in environment variable '%s'", ExtensionVersion, extVersionInEnvVariable, vmextensionhelper.GuestAgentEnvVarExtensionVersion)
+			ext.ExtensionLogger.Warn(msg)
+			ext.ExtensionEvents.LogWarningEvent("ExtensionVersion", msg)
+		}
+	}
+
 	if len(arguments) != 2 {
 		ext.ExtensionLogger.Error("ExtensionError", "vm-application-manager requires an argument")
 		ext.ExtensionEvents.LogCriticalEvent("ExtensionError", "vm-application-manager requires an argument")
 		return errors.Errorf("vm-application-manager requires an argument")
 	}
 	command := arguments[1]
 
+	if command == vmextensionhelper.UpdateOperation.ToString() {
+		if updateToVersion, err := vmextensionhelper.GetGuestAgentEnvironmetVariable(vmextensionhelper.GuestAgentEnvVarUpdateToVersion); err == nil {
+			if updateToVersion != ExtensionVersion {
+				msg := fmt.Sprintf("ExtensionVersion mismatch: compile-time ExtensionVersion value '%s' does not match value '%s' in environment variable '%s'", ExtensionVersion, updateToVersion, vmextensionhelper.GuestAgentEnvVarUpdateToVersion)
+				ext.ExtensionLogger.Warn(msg)
+				ext.ExtensionEvents.LogWarningEvent("ExtensionVersion", msg)
+			}
+		}
+	}
+
 	pid := os.Getpid()
 	ext.ExtensionEvents.LogInformationalEvent("vm-application-manager-process", fmt.Sprintf("VmApplications extension starting, PID: %d, Command: %s", pid, command))
 	defer ext.ExtensionEvents.LogInformationalEvent("vm-application-manager-process", fmt.Sprintf("VmApplications extension exiting, PID: %d, Command: %s", pid, command))
@@ -124,7 +145,7 @@ func getVMExtension() (*vmextensionhelper.VMExtension, error) {
 		return nil, err
 	}
 
-	ii.UninstallCallback = vmAppUninstallCallback
+	ii.UninstallCallback = nil // no need to do any special handling on uninstall, so we can set the callback to nil
 	ii.UpdateCallback = vmAppUpdateCallback
 	ii.LogFileNamePattern = "VmAppExt_%v.log"
 
@@ -257,42 +278,3 @@ func customEnable(ext *vmextensionhelper.VMExtension, hostgaCommunicator hostgac
 
 	return nil
 }
-
-// Callback indicating the extension is being removed
-func vmAppUninstallCallback(ext *vmextensionhelper.VMExtension) error {
-	ext.ExtensionEvents.LogInformationalEvent("Uninstalling", "VmApplications extension - removing all applications for uninstall")
-	hostGaCommunicator := hostgacommunicator.HostGaCommunicator{}
-	err := doVmAppUninstallCallback(ext, &hostGaCommunicator)
-	if err == nil {
-		ext.ExtensionEvents.LogInformationalEvent("Completed", "VmApplications extension uninstalled. Result=Success")
-	} else {
-		ext.ExtensionEvents.LogInformationalEvent(
-			"Completed",
-			fmt.Sprintf("VmApplications extension uninstall finished. Result=Failure;Reason=%v", err.Error()))
-	}
-	return err
-}
-
-func doVmAppUninstallCallback(ext *vmextensionhelper.VMExtension, hostGaCommunicator hostgacommunicator.IHostGaCommunicator) error {
-	packageRegistry, err := packageregistry.New(ext.ExtensionLogger, ext.HandlerEnv, filelockTimeoutDuration)
-	if err != nil {
-		return errors.Wrapf(err, "Could not create package registry")
-	}
-	defer packageRegistry.Close()
-
-	currentPackageRegistry, err := packageRegistry.GetExistingPackages()
-	if err != nil {
-		return errors.Wrapf(err, "Could not read current package registry")
-	}
-
-	// Create an empty incoming collection so we'll create an action plan to remove all applications
-	emptyIncomingCollection := make(packageregistry.VMAppPackageIncomingCollection, 0)
-
-	actionPlan := actionplan.New(currentPackageRegistry, emptyIncomingCollection, ext.HandlerEnv, hostGaCommunicator, ext.ExtensionLogger)
-	commandHandler := commandhandler.CommandHandler{}
-
-	// Removing applications is best effort, so even if there are errors here, we ignore them
-	_, _ = actionPlan.Execute(packageRegistry, ext.ExtensionEvents, &commandHandler)
-
-	return nil
-}

main/main_test.go

@@ -29,7 +29,6 @@ import (
 	handlersettings "github.com/Azure/azure-extension-platform/pkg/settings"
 	"github.com/Azure/azure-extension-platform/pkg/status"
 	"github.com/Azure/azure-extension-platform/vmextension"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -466,84 +465,6 @@ func Test_main_nothingToProcess_withStatus(t *testing.T) {
 	require.Equal(t, requestedSequenceNumber, currentSequenceNumber)
 }
 
-func Test_uninstall_cannotCreatePackageRegistry(t *testing.T) {
-	vmApplications := []extdeserialization.VmAppSetting{}
-	ext := createTestVMExtension(t, vmApplications)
-	hostGaCommunicator := NoopHostGaCommunicator{}
-
-	// Set the config folder to an invalid path so we can't create a package registry
-	ext.HandlerEnv.ConfigFolder = "/yabaflarg/flarpaglarp"
-
-	err := doVmAppUninstallCallback(ext, &hostGaCommunicator)
-	require.Error(t, err)
-	require.EqualError(t, err, cannotCreatePackageRegistryError)
-}
-
-func Test_uninstall_cannotReadPackageRegistry(t *testing.T) {
-	vmApplications := []extdeserialization.VmAppSetting{}
-	ext := createTestVMExtension(t, vmApplications)
-	hostGaCommunicator := NoopHostGaCommunicator{}
-
-	// Write an invalid registry so we can't create a package registry
-	appRegistryFilePath := path.Join(ext.HandlerEnv.ConfigFolder, packageregistry.LocalApplicationRegistryFileName)
-	ioutil.WriteFile(appRegistryFilePath, []byte("}"), 0644)
-	defer os.Remove(appRegistryFilePath)
-
-	err := doVmAppUninstallCallback(ext, &hostGaCommunicator)
-	require.Error(t, err)
-	require.EqualError(t, err, "Could not read current package registry: invalid character '}' looking for beginning of value")
-}
-
-func Test_uninstall_noAppsToUninstall(t *testing.T) {
-	vmApplications := []extdeserialization.VmAppSetting{}
-	ext := createTestVMExtension(t, vmApplications)
-	hostGaCommunicator := NoopHostGaCommunicator{}
-
-	package1 := path.Join(ext.HandlerEnv.ConfigFolder, "package1")
-	package2 := path.Join(ext.HandlerEnv.ConfigFolder, "package2")
-	package1Quotes := fmt.Sprintf("\"%v\"", package1)
-	package2Quotes := fmt.Sprintf("\"%v\"", package2)
-
-	// Create a package registry where the remove commands will write their respective files
-	reg := packageregistry.CurrentPackageRegistry{"package1": &packageregistry.VMAppPackageCurrent{
-		ApplicationName:    "package1",
-		DirectDownloadOnly: false,
-		InstallCommand:     "dontcare",
-		RemoveCommand:      "echo moein > " + package1Quotes,
-		UpdateCommand:      "dontcare",
-		Version:            "1.2.3.1",
-	}, "package2": &packageregistry.VMAppPackageCurrent{
-		ApplicationName:    "package2",
-		DirectDownloadOnly: true,
-		InstallCommand:     "dontcare",
-		RemoveCommand:      "echo moein > " + package2Quotes,
-		UpdateCommand:      "dontcare",
-		Version:            "1.2.3.2",
-	}}
-
-	pkgHndlr, err := packageregistry.New(nopLog(), ext.HandlerEnv, time.Second)
-	assert.NoError(t, err, "operation should not throw error")
-	err = pkgHndlr.WriteToDisk(reg)
-	assert.NoError(t, err, "Should be able to write package registry to disk")
-	pkgHndlr.Close()
-
-	err = doVmAppUninstallCallback(ext, &hostGaCommunicator)
-	require.NoError(t, err)
-
-	// Verify we removed both apps, which deleted the files
-	require.True(t, fileExists(package1), "First application was not removed")
-	require.True(t, fileExists(package2), "Second application was not removed")
-}
-
-func Test_uninstall_uninstallApps(t *testing.T) {
-	vmApplications := []extdeserialization.VmAppSetting{}
-	ext := createTestVMExtension(t, vmApplications)
-	hostGaCommunicator := NoopHostGaCommunicator{}
-
-	err := doVmAppUninstallCallback(ext, &hostGaCommunicator)
-	require.NoError(t, err)
-}
-
 func fileExists(filePath string) bool {
 	if _, err := os.Stat(filePath); errors.Is(err, os.ErrNotExist) {
 		return false