log interface

kvmd/logging.py

@@ -1,5 +1,13 @@
 import sys
+import asyncio
 import logging
+import time
+
+from typing import List
+from typing import Dict
+from typing import AsyncGenerator
+
+import systemd.journal
 
 
 # =====
@@ -13,3 +21,41 @@ def get_logger(depth: int=1) -> logging.Logger:
             break
     name = frames[depth].f_globals["__name__"]
     return logging.getLogger(name)
+
+
+class Log:
+    def __init__(
+        self,
+        services: List[str],
+        loop: asyncio.AbstractEventLoop,
+    ) -> None:
+
+        self.__services = services
+        self.__loop = loop
+
+    async def log(self, seek: int, follow: bool) -> AsyncGenerator[Dict, None]:
+        reader = systemd.journal.Reader()
+        reader.this_boot()
+        reader.this_machine()
+        reader.log_level(systemd.journal.LOG_DEBUG)
+        for service in self.__services:
+            reader.add_match(_SYSTEMD_UNIT=service)
+        if seek > 0:
+            reader.seek_realtime(float(time.time() - seek))
+
+        for entry in reader:
+            yield self.__entry_to_record(entry)
+
+        while follow:
+            entry = reader.get_next()
+            if entry:
+                yield self.__entry_to_record(entry)
+            else:
+                await asyncio.sleep(1)
+
+    def __entry_to_record(self, entry: Dict) -> Dict[str, Dict]:
+        return {
+            "dt": entry["__REALTIME_TIMESTAMP"],
+            "service": entry["_SYSTEMD_UNIT"],
+            "msg": entry["MESSAGE"].rstrip(),
+        }