Add detection for WSL

Fixes #311

os/src/main/java/io/smallrye/common/os/Linux.java

@@ -0,0 +1,56 @@
+package io.smallrye.common.os;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * Utilities pertaining to the Linux operating system.
+ */
+public final class Linux {
+ private Linux() {}
+
+ /**
+ * {@return true if the operating system is the Windows Subsystem for Linux, or false if it is not}
+ */
+ public static boolean isWSL() {
+ return WSL.version >= 1;
+ }
+
+ /**
+ * {@return true if the WSL version is 2 or later, or false if it is not}
+ */
+ public static boolean isWSLv2() {
+ return WSL.version >= 2;
+ }
+
+ /**
+ * Lazy constants for WSL.
+ */
+ private static final class WSL {
+ private static final int version;
+
+ static {
+ if (OS.current() != OS.LINUX) {
+ version = 0;
+ } else {
+ int v;
+ try {
+ String procVersion = Files.readString(Path.of("/proc/version"));
+ if (procVersion.contains("Microsoft")) {
+ // likely version 1
+ v = 1;
+ } else if (procVersion.contains("microsoft")) {
+ // likely version 2 or newer
+ v = 2;
+ } else {
+ v = 0;
+ }
+ } catch (IOException e) {
+ v = 0;
+ }
+ version = v;
+ }
+ }
+ }
+}