Add structured exception data to debug

This adds explicit dumping ground for exceptions we're generating
on TrueNAS.

ixdiagnose/plugins/exceptions.py

@@ -0,0 +1,42 @@
+import json
+
+from .base import Plugin
+from .metrics import PythonMetric
+
+LOG_FILES = (
+    '/var/log/app_lifecycle.log',
+    '/var/log/app_migrations.log',
+    '/var/log/failover.log',
+    '/var/log/middlewared.log',
+    '/var/log/netdata_api.log',
+    '/var/log/zettarepl.log'
+)
+
+
+def parse_log_file(path: str) -> list[dict]:
+    results = []
+    with open(path, 'r') as f:
+        for line in f:
+            if '@cee:{"TNLOG":' not in line:
+                continue
+
+            data = json.loads(line.split('@cee:')[1])
+            results.append(data['TNLOG'])
+
+    return results
+
+
+def gather_exceptions(client: None, resource_type: str) -> dict:
+    results = {}
+    for log in LOG_FILES:
+        try:
+            results[log] = parse_log_file(log)
+        except FileNotFoundError:
+            pass
+
+    return results
+
+
+class LoggedExceptions(Plugin):
+    name = 'logged_exceptions'
+    metrics = [PythonMetric('log_file_exceptions', gather_exceptions, serializable=True)]

ixdiagnose/plugins/factory.py

@@ -9,6 +9,7 @@
 from .containers import Containers
 from .cpu import Cpu
 from .cronjob import Cronjob
+from .exceptions import LoggedExceptions
 from .failover import Failover
 from .ftp import FTP
 from .hardware import Hardware
@@ -58,6 +59,7 @@
     IPMI,
     ISCSI,
     LDAP,
+    LoggedExceptions,
     Network,
     NFS,
     NVME,