[PATCH v2 1/8] dts: add basic logging facility

["Juraj Linkeš" <juraj.linkes@pantheon.tech>]

The logging module provides loggers distinguished by two attributes,
a custom format and a verbosity switch. The loggers log to both console
and more verbosely to files.

Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
 dts/framework/logger.py | 118 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 dts/framework/logger.py

diff --git a/dts/framework/logger.py b/dts/framework/logger.py
new file mode 100644
index 0000000000..2c026ee5eb
--- /dev/null
+++ b/dts/framework/logger.py
@@ -0,0 +1,118 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2010-2014 Intel Corporation
+# Copyright(c) 2022 PANTHEON.tech s.r.o.
+# Copyright(c) 2022 University of New Hampshire
+#
+
+import logging
+import os.path
+from typing import TypedDict
+
+"""
+DTS logger module with several log level. DTS framework and TestSuite log
+will saved into different log files.
+"""
+verbose = False
+date_fmt = "%d/%m/%Y %H:%M:%S"
+stream_fmt = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+
+
+class LoggerDictType(TypedDict):
+    logger: "DTSLOG"
+    name: str
+    node: str
+
+
+# List for saving all using loggers
+global Loggers
+Loggers: list[LoggerDictType] = []
+
+
+def set_verbose() -> None:
+    global verbose
+    verbose = True
+
+
+class DTSLOG(logging.LoggerAdapter):
+    """
+    DTS log class for framework and testsuite.
+    """
+    node: str
+    logger: logging.Logger
+    sh: logging.StreamHandler
+    fh: logging.FileHandler
+    verbose_handler: logging.FileHandler
+
+    def __init__(self, logger: logging.Logger, node: str = "suite"):
+        global log_dir
+
+        self.logger = logger
+        self.logger.setLevel(1)  # 1 means log everything
+
+        self.node = node
+
+        # add handler to emit to stdout
+        sh = logging.StreamHandler()
+        sh.setFormatter(logging.Formatter())
+        sh.setFormatter(logging.Formatter(stream_fmt, date_fmt))
+
+        sh.setLevel(logging.DEBUG)  # file handler default level
+        global verbose
+        if verbose is True:
+            sh.setLevel(logging.DEBUG)
+        else:
+            sh.setLevel(logging.INFO)  # console handler defaultlevel
+
+        self.logger.addHandler(sh)
+        self.sh = sh
+
+        if not os.path.exists("output"):
+            os.mkdir("output")
+
+        fh = logging.FileHandler(f"output/{node}.log")
+        fh.setFormatter(logging.Formatter(
+            fmt='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
+            datefmt=date_fmt))
+
+        fh.setLevel(1)  # We want all the logs we can get in the file
+        self.logger.addHandler(fh)
+        self.fh = fh
+
+        # This outputs EVERYTHING, intended for post-mortem debugging
+        # Also optimized for processing via AWK (awk -F '|' ...)
+        verbose_handler = logging.FileHandler(f"output/{node}.verbose.log")
+        verbose_handler.setFormatter(logging.Formatter(
+            fmt='%(asctime)s|%(name)s|%(levelname)s|%(pathname)s|%(lineno)d|%(funcName)s|'
+                '%(process)d|%(thread)d|%(threadName)s|%(message)s',
+            datefmt=date_fmt))
+
+        verbose_handler.setLevel(1)  # We want all the logs we can get in the file
+        self.logger.addHandler(verbose_handler)
+        self.verbose_handler = verbose_handler
+
+        super(DTSLOG, self).__init__(self.logger, dict(node=self.node))
+
+    def logger_exit(self) -> None:
+        """
+        Remove stream handler and logfile handler.
+        """
+        for handler in (self.sh, self.fh, self.verbose_handler):
+            handler.flush()
+            self.logger.removeHandler(handler)
+
+
+def getLogger(name: str, node: str = "suite") -> DTSLOG:
+    """
+    Get logger handler and if there's no handler for specified Node will create one.
+    """
+    global Loggers
+    # return saved logger
+    logger: LoggerDictType
+    for logger in Loggers:
+        if logger["name"] == name and logger["node"] == node:
+            return logger["logger"]
+
+    # return new logger
+    dts_logger: DTSLOG = DTSLOG(logging.getLogger(name), node)
+    Loggers.append({"logger": dts_logger, "name": name, "node": node})
+    return dts_logger
-- 
2.30.2