Acquire log path from the environment

Dockerfile

@@ -42,6 +42,7 @@ ENV PYTHONPATH="/usr/local/lib"                                            \
     TFW_SNAPSHOTS_DIR="/.tfw/snapshots"                                    \
     TFW_AUTH_KEY="/tmp/tfw-auth.key"                                       \
     TFW_HISTFILE="/home/${AVATAO_USER}/.bash_history"                      \
+    TFW_LOGFILE="/var/log/tfw.log"                                         \
     PROMPT_COMMAND="history -a"
 
 COPY bashrc /tmp

lib/tfw/config/log.py

@@ -5,7 +5,7 @@ from datetime import datetime
 from traceback import format_exception, walk_tb
 from logging import DEBUG, getLogger, Handler, Formatter, Filter
 
-TFW_LOG_PATH = '/var/log/tfw.log'
+from .envvars import TFWENV
 
 
 class COLOR:
@@ -29,20 +29,18 @@ class COLOR:
 
 
 class TFWLog:
-    def __init__(self, path=TFW_LOG_PATH, level=DEBUG):
+    def __init__(self, path=TFWENV.LOGFILE, level=DEBUG):
         self.log = getLogger()
         self.old_level = self.log.level
         self.new_level = level
         self.handler = TFWLogHandler(path)
-        self.handler.setFormatter(TFWLogFormatter())
+        self.handler.setFormatter(TFWLogFormatter(20))
 
     def start(self):
         self.log.setLevel(self.new_level)
         self.log.addHandler(self.handler)
-        self.log.info('Logging started.')
 
     def stop(self):
-        self.log.info('Stop logging.')
         self.log.setLevel(self.old_level)
         self.handler.close()
         self.log.removeHandler(self.handler)
@@ -64,7 +62,7 @@ class TFWLogHandler(Handler):
         self.logfile.close()
 
 class TFWLogFormatter(Formatter):
-    severity = {
+    severity_to_color = {
         'CRITICAL' : COLOR.BOLDRED,
         'ERROR'    : COLOR.RED,
         'WARNING'  : COLOR.YELLOW,
@@ -73,7 +71,8 @@ class TFWLogFormatter(Formatter):
         'NOTSET'   : COLOR.CYAN
     }
 
-    def __init__(self):
+    def __init__(self, limit):
+        self.limit = limit
         self.last_trace = None
         super().__init__()
 
@@ -100,21 +99,20 @@ class TFWLogFormatter(Formatter):
             trace = ''
 
         short_entry = (f'[{COLOR.GREY}{date}{COLOR.RESET}|>'
-                       f'{self.severity[record.levelname]}{record.module}:'
+                       f'{self.severity_to_color[record.levelname]}{record.module}:'
                        f'{record.levelname.lower()}{COLOR.RESET}] {short_message}'
                        f'{trace}')
         long_entry = (f'[{date}|>{record.module}:{record.levelname.lower()}] '
                       f'{long_message}{trace}')
         return short_entry, long_entry
 
-    def trim(self, value, in_dict=False):
+    def trim(self, value):
         if isinstance(value, dict):
-            trimmed = {k: self.trim(v, True) for k, v in value.items()}
-            return trimmed if in_dict else str(trimmed)
+            return {k: self.trim(v, True) for k, v in value.items()}
         if isinstance(value, (int, float)):
             return value
         value_str = str(value)
-        return value_str if len(value_str) <= 20 else f'{value_str[:20]}...'
+        return value_str if len(value_str) <= self.limit else f'{value_str[:self.limit]}...'
 
     @staticmethod
     def fetch_exception_origin(trace):