T5474: establish common file name pattern for XML conf mode commands

We will use _ as CLI level divider. The XML definition filename and also
the Python helper should match the CLI node.

Example:
set interfaces ethernet -> interfaces_ethernet.xml.in
set interfaces bond -> interfaces_bond.xml.in
set service dhcp-server -> service_dhcp-server-xml.in

(cherry picked from commit 4ef110fd2c501b718344c72d495ad7e16d2bd465)

1 files changed, 107 insertions, 0 deletions

diff --git a/src/conf_mode/system_login_banner.py b/src/conf_mode/system_login_banner.py
new file mode 100755
index 000000000..65fa04417
--- /dev/null
+++ b/src/conf_mode/system_login_banner.py
@@ -0,0 +1,107 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2020-2021 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from sys import exit
+from copy import deepcopy
+
+from vyos.config import Config
+from vyos.utils.file import write_file
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+try:
+    with open('/usr/share/vyos/default_motd') as f:
+        motd = f.read()
+except:
+    # Use an empty banner if the default banner file cannot be read
+    motd = "\n"
+
+PRELOGIN_FILE = r'/etc/issue'
+PRELOGIN_NET_FILE = r'/etc/issue.net'
+POSTLOGIN_FILE = r'/etc/motd'
+
+default_config_data = {
+    'issue': 'Welcome to VyOS - \\n \\l\n\n',
+    'issue_net': '',
+    'motd': motd
+}
+
+def get_config(config=None):
+    banner = deepcopy(default_config_data)
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base_level = ['system', 'login', 'banner']
+
+    if not conf.exists(base_level):
+        return banner
+    else:
+        conf.set_level(base_level)
+
+    # Post-Login banner
+    if conf.exists(['post-login']):
+        tmp = conf.return_value(['post-login'])
+        # post-login banner can be empty as well
+        if tmp:
+            tmp = tmp.replace('\\n','\n')
+            tmp = tmp.replace('\\t','\t')
+            # always add newline character
+            tmp += '\n'
+        else:
+            tmp = ''
+
+        banner['motd'] = tmp
+
+    # Pre-Login banner
+    if conf.exists(['pre-login']):
+        tmp = conf.return_value(['pre-login'])
+        # pre-login banner can be empty as well
+        if tmp:
+            tmp = tmp.replace('\\n','\n')
+            tmp = tmp.replace('\\t','\t')
+            # always add newline character
+            tmp += '\n'
+        else:
+            tmp = ''
+
+        banner['issue'] = banner['issue_net'] = tmp
+
+    return banner
+
+def verify(banner):
+    pass
+
+def generate(banner):
+    pass
+
+def apply(banner):
+    write_file(PRELOGIN_FILE, banner['issue'])
+    write_file(PRELOGIN_NET_FILE, banner['issue_net'])
+    write_file(POSTLOGIN_FILE, banner['motd'])
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)