ci: add WSL2 CI

.github/workflows/test.yml

@@ -73,9 +73,35 @@ jobs:
 
   windows:
     name: "Windows tests"
-    runs-on: windows-2022
+    runs-on: windows-2022-8-cores
     timeout-minutes: 30
     steps:
+    - name: Enable WSL2
+      run: |
+        wsl --set-default-version 2
+        # Manually install the latest kernel from MSI
+        Invoke-WebRequest -Uri "https://wslstorestorage.blob.core.windows.net/wslblob/wsl_update_x64.msi" -OutFile "wsl_update_x64.msi"
+        $pwd = (pwd).Path
+        Start-Process msiexec.exe -Wait -ArgumentList "/I $pwd\wsl_update_x64.msi /quiet"
+        wsl --update
+        wsl --status
+        wsl --list --online
+    - name: Install WSL2 distro
+      timeout-minutes: 3
+      run: |
+        # FIXME: At least one distro has to be installed here,
+        # otherwise `wsl --list --verbose` (called from Lima) fails:
+        # https://github.com/lima-vm/lima/pull/1826#issuecomment-1729993334
+        # The distro image itself is not consumed by Lima.
+        # ------------------------------------------------------------------
+        # Ubuntu-22.04:    gets stuck in some infinite loop during adduser
+        # OracleLinux_9_1: almostly silently fails, and just prints "Usage: adduser [options] LOGIN"
+        wsl --install -d openSUSE-Leap-15.5
+        wsl --list --verbose
+    - name: Set gitconfig
+      run: |
+        git config --global core.autocrlf false
+        git config --global core.eol lf
     - uses: actions/checkout@v4
       with:
         fetch-depth: 1
@@ -86,6 +112,19 @@ jobs:
       run: go test -v ./...
     - name: Make
       run: make
+    - name: Smoke test
+      # Make sure the path is set properly and then run limactl
+      run: |
+        $env:Path = 'C:\Program Files\Git\usr\bin;' + $env:Path
+        Set-ItemProperty -Path 'Registry::HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Environment' -Name PATH -Value $env:Path
+        .\_output\bin\limactl.exe start template://experimental/wsl2
+      # TODO: run the full integration tests
+    - name: Debug
+      if: always()
+      run: type C:\Users\runneradmin\.lima\wsl2\ha.stdout.log
+    - name: Debug
+      if: always()
+      run: type C:\Users\runneradmin\.lima\wsl2\ha.stderr.log
 
   integration:
     name: Integration tests

examples/experimental/wsl2.yaml

@@ -4,9 +4,9 @@ vmType: wsl2
 
 images:
 # Source: https://github.com/runfinch/finch-core/blob/main/Dockerfile
-- location: "https://deps.runfinch.com/common/x86-64/finch-rootfs-production-amd64-1690920103.tar.zst"
+- location: "https://deps.runfinch.com/common/x86-64/finch-rootfs-production-amd64-1694791577.tar.gz"
   arch: "x86_64"
-  digest: "sha256:53f2e329b8da0f6a25e025d1f6cc262ae228402ba615ad095739b2f0ec6babc9"
+  digest: "sha256:2d4d2e7386450899c6d0587fd0db21afadb31d974fa744aa9365c883935c5341"
 
 mountType: wsl2
 

pkg/store/instance_windows.go

@@ -35,14 +35,33 @@ func inspectStatus(instDir string, inst *Instance, y *limayaml.LimaYAML) {
 	}
 }
 
-// GetWslStatus runs `wsl --list --verbose` and parses its output
+// GetWslStatus runs `wsl --list --verbose` and parses its output.
+// There are several possible outputs, all listed with their whitespace preserved output below.
 //
-// Expected output (whitespace preserved):
+// (1) Expected output if at least one distro is installed:
 // PS > wsl --list --verbose
 //
 //	NAME      STATE           VERSION
 //
 // * Ubuntu    Stopped         2
+//
+// (2) Expected output when no distros are installed, but WSL is configured properly:
+// PS > wsl --list --verbose
+// Windows Subsystem for Linux has no installed distributions.
+//
+// Use 'wsl.exe --list --online' to list available distributions
+// and 'wsl.exe --install <Distro>' to install.
+//
+// Distributions can also be installed by visiting the Microsoft Store:
+// https://aka.ms/wslstore
+// Error code: Wsl/WSL_E_DEFAULT_DISTRO_NOT_FOUND
+//
+// (3) Expected output when no distros are installed, and WSL2 has no kernel installed:
+//
+// PS > wsl --list --verbose
+// Windows Subsystem for Linux has no installed distributions.
+// Distributions can be installed by visiting the Microsoft Store:
+// https://aka.ms/wslstore
 func GetWslStatus(instName string) (string, error) {
 	distroName := "lima-" + instName
 	out, err := executil.RunUTF16leCommand([]string{
@@ -51,11 +70,25 @@ func GetWslStatus(instName string) (string, error) {
 		"--verbose",
 	})
 	if err != nil {
-		return "", fmt.Errorf("failed to run `wsl --list --verbose`, err: %w", err)
+		return "", fmt.Errorf("failed to run `wsl --list --verbose`, err: %w (out=%q)", err, string(out))
 	}
 
 	if len(out) == 0 {
-		return StatusBroken, fmt.Errorf("failed to read instance state for instance %s, try running `wsl --list --verbose` to debug, err: %w", instName, err)
+		return StatusBroken, fmt.Errorf("failed to read instance state for instance %q, try running `wsl --list --verbose` to debug, err: %w", instName, err)
+	}
+
+	// Check for edge cases first
+	outString := string(out)
+	if strings.Contains(outString, "Windows Subsystem for Linux has no installed distributions.") {
+		if strings.Contains(outString, "Wsl/WSL_E_DEFAULT_DISTRO_NOT_FOUND") {
+			return StatusBroken, fmt.Errorf(
+				"failed to read instance state for instance %q because no distro is installed,"+
+					"try running `wsl --install -d Ubuntu` and then re-running Lima", instName)
+		}
+		return StatusBroken, fmt.Errorf(
+			"failed to read instance state for instance %q because there is no WSL kernel installed,"+
+				"this usually happens when WSL was installed for another user, but never for your user."+
+				"Try running `wsl --install -d Ubuntu` and `wsl --update`, and then re-running Lima", instName)
 	}
 
 	var instState string
@@ -94,7 +127,7 @@ func getWslSSHAddress(instName string) (string, error) {
 	cmd := exec.Command("wsl.exe", "-d", distroName, "bash", "-c", `hostname -I | cut -d ' ' -f1`)
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		return "", fmt.Errorf("failed to get hostname for instance %s, err: %w", instName, err)
+		return "", fmt.Errorf("failed to get hostname for instance %q, err: %w (out=%q)", instName, err, string(out))
 	}
 
 	return strings.TrimSpace(string(out)), nil

pkg/wsl2/lima-init.TEMPLATE

@@ -1,5 +1,6 @@
-set -eu; \
-export LOG_FILE=/var/log/lima-init.log; \
-exec > >(tee \$LOG_FILE) 2>&1; \
-export LIMA_CIDATA_MNT="$(/usr/bin/wslpath '{{.CIDataPath}}')"; \
-exec "\$LIMA_CIDATA_MNT/boot.sh";
+#!/bin/bash
+set -eu
+export LOG_FILE=/var/log/lima-init.log
+exec > >(tee $LOG_FILE) 2>&1
+export LIMA_CIDATA_MNT="$(/usr/bin/wslpath '{{.CIDataPath}}')"
+exec "$LIMA_CIDATA_MNT/boot.sh"

pkg/wsl2/vm_windows.go

@@ -7,8 +7,10 @@ import (
 	"context"
 	_ "embed"
 	"fmt"
+	"os"
 	"os/exec"
 	"path/filepath"
+	"strconv"
 	"strings"
 
 	"github.com/lima-vm/lima/pkg/executil"
@@ -20,13 +22,14 @@ import (
 
 // startVM calls WSL to start a VM.
 func startVM(ctx context.Context, distroName string) error {
-	_, err := executil.RunUTF16leCommand([]string{
+	out, err := executil.RunUTF16leCommand([]string{
 		"wsl.exe",
 		"--distribution",
 		distroName,
 	}, executil.WithContext(&ctx))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to run `wsl.exe --distribution %s`: %w (out=%q)",
+			distroName, err, string(out))
 	}
 	return nil
 }
@@ -35,28 +38,30 @@ func startVM(ctx context.Context, distroName string) error {
 func initVM(ctx context.Context, instanceDir, distroName string) error {
 	baseDisk := filepath.Join(instanceDir, filenames.BaseDisk)
 	logrus.Infof("Importing distro from %q to %q", baseDisk, instanceDir)
-	_, err := executil.RunUTF16leCommand([]string{
+	out, err := executil.RunUTF16leCommand([]string{
 		"wsl.exe",
 		"--import",
 		distroName,
 		instanceDir,
 		baseDisk,
 	}, executil.WithContext(&ctx))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to run `wsl.exe --import %s %s %s`: %w (out=%q)",
+			distroName, instanceDir, baseDisk, err, string(out))
 	}
 	return nil
 }
 
 // stopVM calls WSL to stop a running VM.
 func stopVM(ctx context.Context, distroName string) error {
-	_, err := executil.RunUTF16leCommand([]string{
+	out, err := executil.RunUTF16leCommand([]string{
 		"wsl.exe",
 		"--terminate",
 		distroName,
 	}, executil.WithContext(&ctx))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to run `wsl.exe --terminate %s`: %w (out=%q)",
+			distroName, err, string(out))
 	}
 	return nil
 }
@@ -70,12 +75,39 @@ func provisionVM(ctx context.Context, instanceDir, instanceName, distroName stri
 	m := map[string]string{
 		"CIDataPath": ciDataPath,
 	}
-	out, err := textutil.ExecuteTemplate(limaBoot, m)
+	limaBootB, err := textutil.ExecuteTemplate(limaBoot, m)
 	if err != nil {
 		return fmt.Errorf("failed to construct wsl boot.sh script: %w", err)
 	}
-	outString := strings.Replace(string(out), `\r\n`, `\n`, -1)
-
+	limaBootFile, err := os.CreateTemp("", "lima-wsl2-boot-*.sh")
+	if err != nil {
+		return err
+	}
+	if _, err = limaBootFile.Write(limaBootB); err != nil {
+		return err
+	}
+	limaBootFileWinPath := limaBootFile.Name()
+	if err = limaBootFile.Close(); err != nil {
+		return err
+	}
+	// path should be quoted and use \\ as separator
+	bootFileWSLPath := strconv.Quote(limaBootFileWinPath)
+	limaBootFilePathOnLinuxB, err := exec.Command(
+		"wsl.exe",
+		"-d",
+		distroName,
+		"bash",
+		"-c",
+		fmt.Sprintf("wslpath -u %s", bootFileWSLPath),
+		bootFileWSLPath,
+	).Output()
+	if err != nil {
+		os.RemoveAll(limaBootFileWinPath)
+		// this can return an error with an exit code, which causes it not to be logged
+		// because main.handleExitCoder() traps it, so wrap the error
+		return fmt.Errorf("failed to run wslpath command: %w", err)
+	}
+	limaBootFileLinuxPath := strings.TrimSpace(string(limaBootFilePathOnLinuxB))
 	go func() {
 		cmd := exec.CommandContext(
 			ctx,
@@ -84,12 +116,15 @@ func provisionVM(ctx context.Context, instanceDir, instanceName, distroName stri
 			distroName,
 			"bash",
 			"-c",
-			outString,
+			limaBootFileLinuxPath,
 		)
-		if _, err := cmd.CombinedOutput(); err != nil {
+		out, err := cmd.CombinedOutput()
+		os.RemoveAll(limaBootFileWinPath)
+		logrus.Debugf("%v: %q", cmd.Args, string(out))
+		if err != nil {
 			*errCh <- fmt.Errorf(
-				"error running wslCommand that executes boot.sh: %w, "+
-					"check /var/log/lima-init.log for more details", err)
+				"error running wslCommand that executes boot.sh (%v): %w, "+
+					"check /var/log/lima-init.log for more details (out=%q)", cmd.Args, err, string(out))
 		}
 
 		for {
@@ -130,13 +165,14 @@ func keepAlive(ctx context.Context, distroName string, errCh *chan error) {
 // unregisterVM calls WSL to unregister a VM.
 func unregisterVM(ctx context.Context, distroName string) error {
 	logrus.Info("Unregistering WSL2 VM")
-	_, err := executil.RunUTF16leCommand([]string{
+	out, err := executil.RunUTF16leCommand([]string{
 		"wsl.exe",
 		"--unregister",
 		distroName,
 	}, executil.WithContext(&ctx))
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to run `wsl.exe --unregister %s`: %w (out=%q)",
+			distroName, err, string(out))
 	}
 	return nil
 }