vdk-logging-json: Replace newlines in log messages processed by vdk-l…

…ogging-json (#121)

The message in logs formatted by the vdk-logging-json now
have any newline characters escaped. This change
is made due to how logs are currently parsed by separating
at newline characters.

Signed-off-by: gageorgiev <gageorgiev@vmware.com>

projects/vdk-core/plugins/vdk-logging-json/README.md

@@ -16,6 +16,8 @@ The label names follow the labelling recommendations found at http://ltsv.org/.
 The reason we chose the LTSV naming standard is due to the fact that this plugin was based on a previous LTSV-formatting plugin,
 as well as the fact that there is no single JSON naming standard.
 
+Additionally, newline characters within the message are escaped.
+
 # Usage
 
 Switching vdk logging can be done by simply installing the plugin:

projects/vdk-core/plugins/vdk-logging-json/src/taurus/vdk/logging_json.py

@@ -13,6 +13,14 @@
     '"lineno":"%(lineno)s","funcname":"%(funcName)s","attemptid":"{attempt_id}","message":"%(message)s"'
 )
 
+# this class serves to escape newline characters in the log message
+# as according to https://stackoverflow.com/questions/42068/how-do-i-handle-newlines-in-json
+# it is currently experimental and might be removed
+class RemoveNewlinesFormatter(logging.Formatter):
+    def format(self, record):
+        record.msg = record.msg.replace("\n", "\\n")
+        return super().format(record)
+
 
 @hookimpl(trylast=True)
 def initialize_job(context: JobContext) -> None:
@@ -27,7 +35,7 @@ def initialize_job(context: JobContext) -> None:
     )  # formatting a string containing curly braces
 
     for handler in logging.getLogger().handlers:
-        formatter = logging.Formatter(fmt=detailed_format)
+        formatter = RemoveNewlinesFormatter(fmt=detailed_format)
         formatter.default_time_format = "%Y-%m-%dT%H:%M:%S"
         formatter.default_msec_format = "%s.%03dZ"