Adjust paths in checkups to accommodate NixOS

ee/debug/checkups/binary_directory.go

@@ -6,7 +6,10 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"runtime"
+
+	"github.com/kolide/launcher/ee/allowedcmd"
 )
 
 type BinaryDirectory struct {
@@ -21,7 +24,7 @@ func (c *BinaryDirectory) Name() string {
 func (c *BinaryDirectory) Run(_ context.Context, extraFH io.Writer) error {
 	bindir := getBinDir()
 	if bindir == "" {
-		return errors.New("No default bin directory")
+		return errors.New("no default bin directory")
 	}
 
 	// Note that we're recursing `/usr/local/kolide-k2` and not .../bin. So the counts may not be what
@@ -68,10 +71,46 @@ func getBinDir() string {
 	case "darwin":
 		return "/usr/local/kolide-k2"
 	case "linux":
+		if allowedcmd.IsNixOS() {
+			return getBinDirOnNixOS()
+		}
 		return "/usr/local/kolide-k2"
 	case "windows":
 		return "C:\\Program Files\\Kolide\\Launcher-kolide-k2\\bin"
 	}
 
 	return ""
 }
+
+// getBinDirOnNixOS returns the most likely binary directory for NixOS,
+// looking through the nix store to find it.
+func getBinDirOnNixOS() string {
+	// The binary directory on NixOS will look like, e.g.,:
+	// `/nix/store/w8k7h0s9v64gqj60as756gg81c788zkp-kolide-launcher-1.4.4-6-g33c6fd9/bin`
+	matches, err := filepath.Glob("/nix/store/*-kolide-launcher-*/bin")
+	if err != nil || len(matches) == 0 {
+		return ""
+	}
+
+	if len(matches) == 1 {
+		return matches[0]
+	}
+
+	// In this case, launcher has been installed multiple times. We will pick
+	// the most recent installation.
+	mostRecentDir := ""
+	mostRecentDirTimestamp := int64(0)
+	for _, m := range matches {
+		dirInfo, err := os.Stat(m)
+		if err != nil {
+			continue
+		}
+
+		if dirInfo.ModTime().Unix() > mostRecentDirTimestamp {
+			mostRecentDir = m
+			mostRecentDirTimestamp = dirInfo.ModTime().Unix()
+		}
+	}
+
+	return mostRecentDir
+}

ee/debug/checkups/osquery.go

@@ -4,8 +4,8 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"os"
 	"os/exec"
-	"runtime"
 	"strings"
 	"time"
 
@@ -61,19 +61,15 @@ func (o *osqueryCheckup) version(ctx context.Context) (string, error) {
 }
 
 func (o *osqueryCheckup) interactive(ctx context.Context) error {
-	var launcherPath string
-	switch runtime.GOOS {
-	case "linux", "darwin":
-		launcherPath = "/usr/local/kolide-k2/bin/launcher"
-	case "windows":
-		launcherPath = `C:\Program Files\Kolide\Launcher-kolide-k2\bin\launcher.exe`
+	launcherPath, err := os.Executable()
+	if err != nil {
+		return fmt.Errorf("getting current running executable: %w", err)
 	}
 
 	cmdCtx, cmdCancel := context.WithTimeout(ctx, 20*time.Second)
 	defer cmdCancel()
 
-	// We trust the autoupdate library to find the correct path
-	cmd := exec.CommandContext(cmdCtx, launcherPath, "interactive") //nolint:forbidigo // We trust the autoupdate library to find the correct path
+	cmd := exec.CommandContext(cmdCtx, launcherPath, "interactive") //nolint:forbidigo // It is safe to exec the current running executable
 	hideWindow(cmd)
 	cmd.Stdin = strings.NewReader(`select * from osquery_info;`)