monitoring: T3872: Add python handler for service monitoring

1 files changed, 143 insertions, 0 deletions

diff --git a/src/conf_mode/service_monitoring.py b/src/conf_mode/service_monitoring.py
new file mode 100755
index 000000000..e14ad78fc
--- /dev/null
+++ b/src/conf_mode/service_monitoring.py
@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 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/>.
+
+import os
+import json
+
+from sys import exit
+
+from vyos.config import Config
+from vyos.template import render
+from vyos.util import call
+from vyos.util import chown
+from vyos.util import cmd
+from vyos import ConfigError
+from vyos import airbag
+airbag.enable()
+
+
+cache_dir = '/run/telegraf/.cache'
+config_telegraf = '/run/telegraf/vyos-telegraf.conf'
+custom_scripts_dir = '/etc/telegraf/custom_scripts'
+syslog_telegraf = '/etc/rsyslog.d/50-telegraf.conf'
+systemd_telegraf_service = '/etc/systemd/system/vyos-telegraf.service'
+systemd_telegraf_override_dir = '/etc/systemd/system/vyos-telegraf.service.d'
+systemd_override = f'{systemd_telegraf_override_dir}/10-override.conf'
+
+
+def get_nft_filter_chains():
+    """
+    Get nft chains for table filter
+    """
+    nft = cmd('nft --json list table ip filter')
+    nft = json.loads(nft)
+    chain_list = []
+
+    for output in nft['nftables']:
+        if 'chain' in output:
+            chain = output['chain']['name']
+            chain_list.append(chain)
+
+    return chain_list
+
+def get_config(config=None):
+
+    if config:
+        conf = config
+    else:
+        conf = Config()
+    base = ['service', 'monitoring']
+    monitoring = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True,
+                                    no_tag_node_value_mangle=True)
+
+    if monitoring:
+        # Set default value for bucket if not configured
+        if 'bucket' not in monitoring:
+            monitoring['bucket'] = cmd('cat /etc/hostname')
+
+        # Get nftables chains
+        monitoring['nft_chains'] = get_nft_filter_chains()
+        monitoring['custom_scripts_dir'] = custom_scripts_dir
+
+    return monitoring
+
+def verify(monitoring):
+    # bail out early - looks like removal from running config
+    if not monitoring:
+        return None
+
+    if 'login' not in monitoring['authentication'] or 'token' not in monitoring['authentication']:
+        raise ConfigError(f'Authentication "login and token" are mandatory!')
+
+    if 'url' not in monitoring:
+        raise ConfigError(f'Monitoring "url" is mandatory!')
+
+    return None
+
+def generate(monitoring):
+    if not monitoring:
+        # Delete config file
+        if os.path.isfile(config_telegraf):
+            os.unlink(config_telegraf)
+        if os.path.isfile(systemd_override):
+            os.unlink(systemd_override)
+        if os.path.isfile(syslog_telegraf):
+            os.unlink(syslog_telegraf)
+
+
+        return None
+
+    # Create telegraf cache dir
+    if not os.path.exists(cache_dir):
+        os.mkdir(cache_dir)
+
+    chown(cache_dir, 'telegraf', 'vyattacfg')
+
+    # Create systemd override dir
+    if not os.path.exists(systemd_telegraf_override_dir):
+        os.mkdir(systemd_telegraf_override_dir)
+
+    # Create custome scripts dir
+    if not os.path.exists(custom_scripts_dir):
+        os.mkdir(custom_scripts_dir)
+
+    # Render telegraf configuration and systemd override
+    render(config_telegraf, 'monitoring/telegraf.tmpl', monitoring)
+    render(systemd_telegraf_service, 'monitoring/systemd_vyos_telegraf_service.tmpl', monitoring)
+    render(systemd_override, 'monitoring/override.conf.tmpl', monitoring, permission=0o640)
+    render(syslog_telegraf, 'monitoring/syslog_telegraf.tmpl', monitoring)
+
+    return None
+
+def apply(monitoring):
+    # Reload systemd manager configuration
+    call('systemctl daemon-reload')
+    if monitoring:
+        call('systemctl restart vyos-telegraf.service')
+    else:
+        call('systemctl stop vyos-telegraf.service')
+    # Telegraf include custom rsyslog config changes
+    call('systemctl restart rsyslog')
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)