From 4ddfe9b7e72e4f1e1fc8e70c5239bf09644e6d9b Mon Sep 17 00:00:00 2001
From: Viacheslav Hletenko <v.gletenko@vyos.io>
Date: Tue, 8 Feb 2022 08:38:12 +0000
Subject: monitoring: T3872: Add input filter for firewall InfluxDB2

Input filter for firewall allows to get bytes/counters from
nftables in format, required for InfluxDB2
---
 data/templates/monitoring/telegraf.tmpl            |  3 +-
 .../custom_scripts/show_firewall_input_filter.py   | 73 ++++++++++++++++++++++
 2 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100755 src/etc/telegraf/custom_scripts/show_firewall_input_filter.py

diff --git a/data/templates/monitoring/telegraf.tmpl b/data/templates/monitoring/telegraf.tmpl
index 465b58c80..d3145a500 100644
--- a/data/templates/monitoring/telegraf.tmpl
+++ b/data/templates/monitoring/telegraf.tmpl
@@ -17,7 +17,7 @@
 [[outputs.influxdb_v2]]
   urls = ["{{ url }}:{{ port }}"]
   insecure_skip_verify = true
-  token = "{{ authentication.token }}"
+  token = "$INFLUX_TOKEN"
   organization = "{{ authentication.organization }}"
   bucket = "{{ bucket }}"
 [[inputs.cpu]]
@@ -52,6 +52,7 @@
   syslog_standard = "RFC3164"
 [[inputs.exec]]
   commands = [
+    "{{ custom_scripts_dir }}/show_firewall_input_filter.py",
     "{{ custom_scripts_dir }}/show_interfaces_input_filter.py",
     "{{ custom_scripts_dir }}/vyos_services_input_filter.py"
   ]
diff --git a/src/etc/telegraf/custom_scripts/show_firewall_input_filter.py b/src/etc/telegraf/custom_scripts/show_firewall_input_filter.py
new file mode 100755
index 000000000..bf4bfd05d
--- /dev/null
+++ b/src/etc/telegraf/custom_scripts/show_firewall_input_filter.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+import json
+import re
+import time
+
+from vyos.util import cmd
+
+
+def get_nft_filter_chains():
+    """
+    Get list of nft chains for table filter
+    """
+    nft = cmd('/usr/sbin/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_nftables_details(name):
+    """
+    Get dict, counters packets and bytes for chain
+    """
+    command = f'/usr/sbin/nft list chain ip filter {name}'
+    try:
+        results = cmd(command)
+    except:
+        return {}
+
+    # Trick to remove 'NAME_' from chain name in the comment
+    # It was added to any chain T4218
+    # counter packets 0 bytes 0 return comment "FOO default-action accept"
+    comment_name = name.replace("NAME_", "")
+    out = {}
+    for line in results.split('\n'):
+        comment_search = re.search(rf'{comment_name}[\- ](\d+|default-action)', line)
+        if not comment_search:
+            continue
+
+        rule = {}
+        rule_id = comment_search[1]
+        counter_search = re.search(r'counter packets (\d+) bytes (\d+)', line)
+        if counter_search:
+            rule['packets'] = counter_search[1]
+            rule['bytes'] = counter_search[2]
+
+        rule['conditions'] = re.sub(r'(\b(counter packets \d+ bytes \d+|drop|reject|return|log)\b|comment "[\w\-]+")', '', line).strip()
+        out[rule_id] = rule
+    return out
+
+
+def get_nft_telegraf(name):
+    """
+    Get data for telegraf in influxDB format
+    """
+    for rule, rule_config in get_nftables_details(name).items():
+        print(f'nftables,table=filter,chain={name},'
+              f'ruleid={rule} '
+              f'pkts={rule_config["packets"]}i,'
+              f'bytes={rule_config["bytes"]}i '
+              f'{str(int(time.time()))}000000000')
+
+
+chains = get_nft_filter_chains()
+
+for chain in chains:
+    get_nft_telegraf(chain)
-- 
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