examples: add python example for reapply

(cherry picked from commit a467f55bef47056fdd92832337007e5390de47f2)

2 files changed, 148 insertions, 0 deletions

diff --git a/Makefile.examples b/Makefile.examples
index 076af724ae..3b26220990 100644
--- a/Makefile.examples
+++ b/Makefile.examples
@@ -182,6 +182,7 @@ EXTRA_DIST += \
 	examples/python/gi/add_connection.py \
 	examples/python/gi/checkpoint.py \
 	examples/python/gi/deactivate-all.py \
+	examples/python/gi/device-reapply.py \
 	examples/python/gi/device-state-ip4config.py \
 	examples/python/gi/dns.py \
 	examples/python/gi/firewall-zone.py \
diff --git a/examples/python/gi/device-reapply.py b/examples/python/gi/device-reapply.py
new file mode 100755
index 0000000000..9f5d330677
--- /dev/null
+++ b/examples/python/gi/device-reapply.py
@@ -0,0 +1,147 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+import os
+import sys
+
+import gi
+
+gi.require_version("NM", "1.0")
+from gi.repository import NM, GLib, Gio, GObject
+
+
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
+
+def kf_from_data(data):
+    kf = GLib.KeyFile.new()
+    kf.load_from_data(data, 18446744073709551615, GLib.KeyFileFlags.NONE)
+    return kf
+
+
+def kf_to_data(kf):
+    data, l = kf.to_data()
+    return data
+
+
+def connection_to_kf(connection):
+    return kf_to_data(NM.keyfile_write(connection, NM.KeyfileHandlerFlags.NONE))
+
+
+def connection_from_kf(data):
+    base_dir = os.getcwd()
+    return NM.keyfile_read(kf_from_data(data), base_dir, NM.KeyfileHandlerFlags.NONE)
+
+
+def connection_from_stdin():
+    return connection_from_kf(sys.stdin.read())
+
+
+def device_get_applied_connection(device):
+    mainloop = GLib.MainLoop()
+    r = []
+
+    def cb(device, result):
+        try:
+            connection, version_id = device.get_applied_connection_finish(result)
+        except Exception as e:
+            r.append(e)
+        else:
+            r.append(connection)
+            r.append(version_id)
+        mainloop.quit()
+
+    device.get_applied_connection_async(0, None, cb)
+    mainloop.run()
+    if len(r) == 1:
+        raise r[0]
+    connection, version_id = r
+    return connection, version_id
+
+
+def device_reapply(device, connection, version_id, reapply_flags):
+    mainloop = GLib.MainLoop()
+    r = []
+
+    def cb(device, result):
+        try:
+            device.reapply_finish(result)
+        except Exception as e:
+            r.append(e)
+        mainloop.quit()
+
+    device.reapply_async(connection, version_id or 0, reapply_flags, None, cb)
+    mainloop.run()
+    if len(r) == 1:
+        raise r[0]
+
+
+def parse_args():
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        prog="device-reapply.py",
+        description="Example program to interact with the applied connection",
+    )
+
+    parser.add_argument("mode", choices=["get", "reapply", "modify"])
+    parser.add_argument("device")
+    parser.add_argument("-V", "--version-id", type=int)
+    parser.add_argument("-s", "--stdin", action="store_true")
+    parser.add_argument("-p", "--preserve-external-ip", action="store_true")
+
+    return parser.parse_args()
+
+
+def main():
+    args = parse_args()
+
+    nmc = NM.Client.new()
+
+    device = [d for d in nmc.get_devices() if d.get_iface() == args.device]
+    if not device:
+        raise Exception(f'Device "{args.device}" not found')
+    if len(device) != 1:
+        raise Exception(f'Not unique device "{args.device}" found')
+    device = device[0]
+
+    assert not args.stdin or args.mode == "modify"
+    assert not args.preserve_external_ip or args.mode in ["modify", "reapply"]
+
+    if args.mode == "get":
+        connection, version_id = device_get_applied_connection(device)
+
+        version_id_matches = args.version_id is None or args.version_id == version_id
+
+        print(
+            f'# Applied connection on "{device.get_iface()}": "{connection.get_id()}" ({connection.get_uuid()}, {connection.get_connection_type()})'
+        )
+        s = "" if version_id_matches else f" (expected {args.version_id})"
+        print(f"# version-id={version_id}{s}")
+        print(f"#")
+        print(f"{connection_to_kf(connection)}")
+
+        if not version_id_matches:
+            eprint(
+                f"Applied version-id does not match (expects {args.version_id} but got {version_id})"
+            )
+            sys.exit(1)
+        sys.exit(0)
+
+    if args.mode == "reapply":
+        new_connection = None
+    elif args.stdin:
+        new_connection = connection_from_stdin()
+    else:
+        new_connection, _ = device_get_applied_connection(device)
+
+    reapply_flags = 0
+    if args.preserve_external_ip:
+        reapply_flags = 1  # NM.DeviceReapplyFlags.PRESERVE_EXTERNAL_IP
+
+    device_reapply(device, new_connection, args.version_id, reapply_flags)
+
+
+if __name__ == "__main__":
+    main()