ARTEMIS-4390 Fix the upgrade-linux smoke test on Windows

The test cannot work on Windows unless I can make the `upgrade` CLI command
respect my choice to upgrade a Linux distribution. This commit therefore adds
a new `--linux` option for the `upgrade` command, and leverages it in the
`upgrade-linux` smoke test.

* The `--cygwin` option has been preserved for backwards compatibility.
* The `IS_CYGWIN` attribute has been renamed to `IS_NIX` to reflect the change.
* The OS "recognition" method (in `InstallAbstract::run`) has been updated to
  reflect the need for enforcing *nix behavior, which is now the default if all
  other methods fail.

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/Create.java

@@ -756,7 +756,7 @@ public class Create extends InstallAbstract {
          writeEtc(ETC_ARTEMIS_PROFILE_CMD, etcFolder, filters, false);
       }
 
-      if (!IS_WINDOWS || IS_CYGWIN) {
+      if (IS_NIX) {
          write(BIN_ARTEMIS, filters, true);
          makeExec(BIN_ARTEMIS);
          write(BIN_ARTEMIS_SERVICE, filters, true);
@@ -847,7 +847,7 @@ public class Create extends InstallAbstract {
       File service = new File(directory, BIN_ARTEMIS_SERVICE);
       context.out.println("");
 
-      if (!IS_WINDOWS || IS_CYGWIN) {
+      if (IS_NIX) {
          context.out.println("Or you can run the broker in the background using:");
          context.out.println("");
          context.out.println(String.format("   \"%s\" start", path(service)));

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/InstallAbstract.java

@@ -52,8 +52,8 @@ public class InstallAbstract extends InputAbstract {
    @Option(names = "--windows", description = "Force Windows script creation. Default: based on your actual system.")
    protected boolean windows = false;
 
-   @Option(names = "--cygwin", description = "Force Cygwin script creation. Default: based on your actual system.")
-   protected boolean cygwin = false;
+   @Option(names = {"--cygwin", "--linux"}, description = "Force Linux or Cygwin script creation. Default: based on your actual system.")
+   protected boolean nix = false;
 
    @Option(names = "--java-options", description = "Extra Java options to be passed to the profile.")
    protected List<String> javaOptions;
@@ -93,12 +93,29 @@ public class InstallAbstract extends InputAbstract {
    }
 
    protected boolean IS_WINDOWS;
-   protected boolean IS_CYGWIN;
+   protected boolean IS_NIX;
 
    public Object run(ActionContext context) throws Exception {
-      IS_WINDOWS = windows | System.getProperty("os.name").toLowerCase().trim().startsWith("win");
-      IS_CYGWIN = cygwin | IS_WINDOWS && "cygwin".equals(System.getenv("OSTYPE"));
-
+      IS_NIX = false;
+      IS_WINDOWS = false;
+      if (nix) {
+         IS_NIX = true;
+         return null;
+      }
+      if (windows) {
+         IS_WINDOWS = true;
+         return null;
+      }
+      if ("cygwin".equals(System.getenv("OSTYPE"))) {
+         IS_NIX = true;
+         return null;
+      }
+      if (System.getProperty("os.name").toLowerCase().trim().startsWith("win")) {
+         IS_WINDOWS = true;
+         return null;
+      }
+      // Fallback to *nix
+      IS_NIX = true;
       return null;
    }
 
@@ -140,7 +157,7 @@ public class InstallAbstract extends InputAbstract {
 
       // and then writing out in the new target encoding..  Let's also replace \n with the values
       // that is correct for the current platform.
-      String separator = unixTarget && IS_CYGWIN ? "\n" : System.getProperty("line.separator");
+      String separator = unixTarget && IS_NIX ? "\n" : System.getProperty("line.separator");
       content = content.replaceAll("\\r?\\n", Matcher.quoteReplacement(separator));
       ByteArrayInputStream in = new ByteArrayInputStream(content.getBytes(encoding));
       try (FileOutputStream fout = new FileOutputStream(target)) {

artemis-cli/src/main/java/org/apache/activemq/artemis/cli/commands/Upgrade.java

@@ -89,7 +89,7 @@ public class Upgrade extends InstallAbstract {
       final File artemisScript = new File(bin, Create.ARTEMIS);
 
       if (etc == null || etc.equals("etc")) {
-         if (IS_WINDOWS && !IS_CYGWIN) {
+         if (IS_WINDOWS) {
             String pattern = "set ARTEMIS_INSTANCE_ETC=";
             etcFolder = getETC(context, etcFolder, artemisCmdScript, pattern);
          } else {
@@ -157,7 +157,7 @@ public class Upgrade extends InstallAbstract {
                     "set ARTEMIS_INSTANCE=\"", "set ARTEMIS_DATA_DIR=", "set ARTEMIS_ETC_DIR=", "set ARTEMIS_OOME_DUMP=", "set ARTEMIS_INSTANCE_URI=", "set ARTEMIS_INSTANCE_ETC_URI=");
       }
 
-      if (!IS_WINDOWS || IS_CYGWIN) {
+      if (IS_NIX) {
          final File artemisScriptTmp = new File(tmp, Create.ARTEMIS);
          final File artemisScriptBkp = new File(binBkp, Create.ARTEMIS);
 

tests/smoke-tests/pom.xml

@@ -1276,8 +1276,11 @@
                   </goals>
                   <configuration>
                      <instance>${basedir}/target/classes/servers/linuxUpgrade</instance>
+                     <args>
+                        <arg>--linux</arg>
                         <!-- we don't pass the java memory argumnent on purpose,
                              as the upgrade should keep the relevant JVM arguments during the upgrade -->
+                     </args>
                   </configuration>
                </execution>
                <execution>