extract-fw-host-vars.py: write host_vars/<host>/<short>-ipt-server.yml by default.

Without -o the script now writes the standard host_vars file (relative to
the script, independent of the cwd). An existing file is only overwritten
with --force; this is checked before connecting to the host. -o - prints
to stdout.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

extract-fw-host-vars.py

@@ -3,13 +3,17 @@
 Extract ipt-firewall configuration from a host and generate host_vars YAML.
 
 Reads /etc/ipt-firewall/{interfaces,main}_ipv{4,6}.conf via SSH,
-maps all variables to Ansible fw_* names, and writes a host_vars file.
+maps all variables to Ansible fw_* names, and writes a host_vars file
+(default: host_vars/<hostname>/<short-hostname>-ipt-server.yml next to this
+script; an existing file is only overwritten with --force).
 
 Usage:
-    ./extract-fw-host-vars.py <hostname> [--user USER] [--port PORT] [--sudo] [--from-dir DIR] [--output FILE] [--dry-run]
+    ./extract-fw-host-vars.py <hostname> [--user USER] [--port PORT] [--sudo] [--from-dir DIR]
+                              [--output FILE|-] [--force] [--dry-run]
 
 Example:
-    ./extract-fw-host-vars.py cl-01.oopen.de
+    ./extract-fw-host-vars.py cl-01.oopen.de          # -> host_vars/cl-01.oopen.de/cl-01-ipt-server.yml
+    ./extract-fw-host-vars.py cl-01.oopen.de -o -     # print to stdout
     ./extract-fw-host-vars.py cl-01.oopen.de --user root --dry-run
 """
 
@@ -746,7 +750,10 @@ def main():
     parser.add_argument("hostname", help="Target hostname (must be in SSH config or known_hosts)")
     parser.add_argument("--user", "-u", default="chris", help="SSH user (default: chris)")
     parser.add_argument("--port", "-p", type=int, default=None, help="SSH port (default: 22)")
-    parser.add_argument("--output", "-o", default=None, help="Output file (default: stdout)")
+    parser.add_argument("--output", "-o", default=None,
+                        help="Output file, '-' for stdout "
+                             "(default: host_vars/<hostname>/<short-hostname>-ipt-server.yml)")
+    parser.add_argument("--force", "-f", action="store_true", help="Overwrite an existing output file")
     parser.add_argument("--sudo", "-s", action="store_true",
                         help="Read files via sudo (prompts for sudo password once)")
     parser.add_argument("--from-dir", "-d", default=None,
@@ -770,6 +777,21 @@ def main():
             print(f"ssh {args.user}@{hostname} {cmd} {path}")
         return
 
+    # Determine the output file first, so an existing file aborts before any SSH
+    out_path = None
+    if args.output != "-":
+        if args.output:
+            out_path = Path(args.output)
+        else:
+            # Same as ${HOSTNAME%.*.*} in the docs: a.mx.oopen.de -> a.mx
+            short = hostname.rsplit(".", 2)[0] if hostname.count(".") >= 2 else hostname
+            out_path = Path(__file__).resolve().parent / "host_vars" / hostname / f"{short}-ipt-server.yml"
+
+        if out_path.exists() and not args.force:
+            print(f"ERROR: {out_path} already exists — use --force to overwrite "
+                  "or -o - to print to stdout", file=sys.stderr)
+            sys.exit(1)
+
     contents = {}
     if args.from_dir:
         for key, path in files.items():
@@ -814,13 +836,13 @@ def main():
 
     yaml_text = render_yaml(hostname, host_vars, all_warnings)
 
-    if args.output:
-        out_path = Path(args.output)
+    if out_path is None:
+        print(yaml_text)
+        return
+
     out_path.parent.mkdir(parents=True, exist_ok=True)
     out_path.write_text(yaml_text)
     print(f"Written to {out_path}", file=sys.stderr)
-    else:
-        print(yaml_text)
 
 
 if __name__ == "__main__":

roles/ipt-server/MIGRATION.md

@@ -56,12 +56,15 @@ mappt alle Variablen auf die `fw_*`-Ansible-Variablen und schreibt eine fertige
 cd /path/to/ansible/oopen-server
 HOSTNAME=<hostname>
 
-./extract-fw-host-vars.py ${HOSTNAME} --sudo \
-  -o host_vars/${HOSTNAME}/${HOSTNAME%.*.*}-ipt-server.yml
+./extract-fw-host-vars.py ${HOSTNAME} --sudo
 ```
 
-Das Skript fragt einmalig nach dem `sudo`-Passwort. Kann eine der Dateien nicht
-gelesen werden, bricht es ab, ohne etwas zu schreiben.
+Das Skript fragt einmalig nach dem `sudo`-Passwort und schreibt nach
+`host_vars/${HOSTNAME}/${HOSTNAME%.*.*}-ipt-server.yml`. Eine vorhandene Datei
+wird nur mit `--force` überschrieben (dabei wird `fw_manage_config` wieder
+`false`); mit `-o -` geht die Ausgabe nach stdout, mit `-o DATEI` in eine
+andere Datei. Kann eine der Conf-Dateien nicht gelesen werden, bricht das
+Skript ab, ohne etwas zu schreiben.
 
 Alternativ ohne Passwortabfrage (sudo über `ansible_become_password` aus dem Vault):
 die Dateien mit Ansible holen und lokal einlesen:
@@ -71,8 +74,7 @@ for f in interfaces_ipv4 interfaces_ipv6 main_ipv4 main_ipv6 ; do
    ansible ${HOSTNAME} -b -m fetch \
       -a "src=/etc/ipt-firewall/${f}.conf dest=/tmp/fw-${HOSTNAME}/ flat=yes"
 done
-./extract-fw-host-vars.py ${HOSTNAME} --from-dir /tmp/fw-${HOSTNAME} \
-  -o host_vars/${HOSTNAME}/${HOSTNAME%.*.*}-ipt-server.yml
+./extract-fw-host-vars.py ${HOSTNAME} --from-dir /tmp/fw-${HOSTNAME}
 rm -rf /tmp/fw-${HOSTNAME}
 ```