Cleanup plugin bin directories (#41907)

This commit adds deletion of the bin directory to postrm cleanup. While
the package's bin files are cleaned up by the package manager, plugins
may have created subdirectories under bin. We already cleanup plugins,
but not the extra bin dirs their installation created.

closes #18109

Author: rjernst

distribution/packages/src/common/scripts/postrm

@@ -8,7 +8,6 @@
 #   On RedHat,
 #       $1=0         : indicates a removal
 #       $1=1         : indicates an upgrade
-
 REMOVE_DIRS=false
 REMOVE_USER_AND_GROUP=false
 
@@ -55,6 +54,13 @@ if [ "$REMOVE_DIRS" = "true" ]; then
         echo " OK"
     fi
 
+    # plugins may have contained bin files
+    if [ -d /usr/share/elasticsearch/bin ]; then
+        echo -n "Deleting plugin bin directories..."
+        rm -rf /usr/share/elasticsearch/bin
+        echo " OK"
+    fi
+
     if [ -d /var/run/elasticsearch ]; then
         echo -n "Deleting PID directory..."
         rm -rf /var/run/elasticsearch

qa/vagrant/src/main/java/org/elasticsearch/packaging/test/PackageTestCase.java

@@ -169,6 +169,9 @@ public void test40StartServer() throws Exception {
     public void test50Remove() throws Exception {
         assumeThat(installation, is(notNullValue()));
 
+        // add fake bin directory as if a plugin was installed
+        Files.createDirectories(installation.bin.resolve("myplugin"));
+
         remove(distribution());
 
         // removing must stop the service