vm.args check for name/sname parameter

The current version of extended_bin checks if there is a name or sname parameter in vm.args and refuses to start if there is none. However, it is allowed that the vm.args file (more abstract, any -args_file that is given to erl/erlexec etc) itself may contain -args_file parameters (see http://erlang.org/doc/man/erl.html), which may contain the name/sname parameters.

This change will recursively scan the files mentioned in -args_file parameters in vm.args as well as -args_file parameters in the mentioned files etcetc, and return the first occurence of a name/sname parameter.

Two points are worth mentioning, though:
- The name/sname check works only with absolute paths in the args_file parameters. Relative paths are probably a bad idea there, anyway, since it would make any setup rather fragile.
- There is no check for circular dependencies. There was none before, and this change does not add any.

1 files changed, 16 insertions, 2 deletions

diff --git a/priv/templates/extended_bin b/priv/templates/extended_bin
index 2580dcc..e3b8f1a 100755
--- a/priv/templates/extended_bin
+++ b/priv/templates/extended_bin
@@ -294,8 +294,22 @@ export LD_LIBRARY_PATH="$ERTS_DIR/lib:$LD_LIBRARY_PATH"
 ERTS_LIB_DIR="$(dirname "$ERTS_DIR")/lib"
 
 VMARGS_PATH=$(add_path vm.args $VMARGS_PATH)
-# Extract the target node name from node.args
-NAME_ARG=$(egrep '^-s?name' "$VMARGS_PATH" || true)
+# Extract the target node name from vm.args or referenced args_files
+NAME_ARG=$(awk 'function find_name(file) {
+        while ((getline line<file)>0) {
+                if (line~/^-args_file\s+/) {
+                        gsub(/^-args_file\s+/, "", line)
+                        find_name(line)
+                }
+                else if (line~/^-s?name\s+/) {
+                        print line
+                        exit
+                }
+        }
+}
+{
+        find_name(FILENAME)
+}' "$VMARGS_PATH")
 # Perform replacement of variables in ${NAME_ARG}
 NAME_ARG=$(eval echo "${NAME_ARG}")