nixos/glusterfs: fix dangling glusterfind hook symlink and install group presets (#534709)

nixos/modules/services/network-filesystems/glusterfs.nix

@@ -180,7 +180,9 @@ in
       # Excludes one hook due to missing SELinux binaries.
       + ''
         mkdir -p /var/lib/glusterd/hooks/
-        ${rsync}/bin/rsync -a --exclude="S10selinux-label-brick.sh" ${glusterfs}/var/lib/glusterd/hooks/ /var/lib/glusterd/hooks/
+        # --copy-unsafe-links: the glusterfind hook is a symlink into the package's
+        # libexec that would dangle once copied verbatim into / (#257863).
+        ${rsync}/bin/rsync -a --copy-unsafe-links --exclude="S10selinux-label-brick.sh" ${glusterfs}/var/lib/glusterd/hooks/ /var/lib/glusterd/hooks/
 
         ${tlsCmd}
       ''
@@ -189,6 +191,12 @@ in
       + ''
         mkdir -p /var/lib/glusterd/glusterfind/.keys
         mkdir -p /var/lib/glusterd/hooks/1/delete/post/
+      ''
+      # Volume option presets, installed by upstream under $out/var; copy them so
+      # `gluster volume set <vol> group <name>` works (#33159).
+      + ''
+        mkdir -p /var/lib/glusterd/groups/
+        ${rsync}/bin/rsync -a ${glusterfs}/var/lib/glusterd/groups/ /var/lib/glusterd/groups/
       '';
 
       serviceConfig = {

nixos/tests/glusterfs.nix

@@ -49,6 +49,14 @@ in
     server1.wait_for_unit("glusterd.service")
     server2.wait_for_unit("glusterd.service")
 
+    # The glusterfind delete hook must be a real file, not the dangling
+    # symlink it used to be after being copied out of the package (#257863).
+    server1.succeed("test -f /var/lib/glusterd/hooks/1/delete/post/S57glusterfind-delete-post")
+    server1.fail("test -L /var/lib/glusterd/hooks/1/delete/post/S57glusterfind-delete-post")
+
+    # The volume option presets must be installed (#33159).
+    server1.succeed("test -f /var/lib/glusterd/groups/metadata-cache")
+
     server1.wait_until_succeeds("gluster peer status")
     server2.wait_until_succeeds("gluster peer status")
 
@@ -64,6 +72,9 @@ in
     server1.succeed("gluster volume create gv0 server1:/data/vg0 server2:/data/vg0")
     server1.succeed("gluster volume start gv0")
 
+    # Applying a group preset needs /var/lib/glusterd/groups populated (#33159).
+    server1.succeed("gluster volume set gv0 group metadata-cache")
+
     # test clients
     client1.wait_for_unit("gluster.mount")
     client2.wait_for_unit("gluster.mount")