refactor: refactor logs command library (aws#2862)

* refactor logs command library

* re-organize due to click usage

* address comments

* adding pylint disable for console consumer

* make pylint happy with python 3.6

Co-authored-by: Mathieu Grandis <[email protected]>

samcli/commands/logs/command.py

@@ -111,24 +111,13 @@ def do_cli(function_name, stack_name, filter_pattern, tailing, start_time, end_t
         filter_pattern=filter_pattern,
         start_time=start_time,
         end_time=end_time,
-        # output_file is not yet supported by CLI
-        output_file=None,
     ) as context:
 
         if tailing:
-            events_iterable = context.fetcher.tail(
-                context.log_group_name, filter_pattern=context.filter_pattern, start=context.start_time
-            )
+            context.fetcher.tail(start_time=context.start_time, filter_pattern=context.filter_pattern)
         else:
-            events_iterable = context.fetcher.fetch(
-                context.log_group_name,
+            context.fetcher.load_time_period(
+                start_time=context.start_time,
+                end_time=context.end_time,
                 filter_pattern=context.filter_pattern,
-                start=context.start_time,
-                end=context.end_time,
             )
-
-        formatted_events = context.formatter.do_format(events_iterable)
-
-        for event in formatted_events:
-            # New line is not necessary. It is already in the log events sent by CloudWatch
-            click.echo(event, nl=False)

samcli/commands/logs/console_consumers.py

@@ -0,0 +1,18 @@
+"""
+Consumers that will print out events to console
+"""
+
+import click
+
+from samcli.lib.observability.cw_logs.cw_log_event import CWLogEvent
+from samcli.lib.observability.observability_info_puller import ObservabilityEventConsumer
+
+
+class CWConsoleEventConsumer(ObservabilityEventConsumer[CWLogEvent]):
+    """
+    Consumer implementation that will consume given event as outputting into console
+    """
+
+    # pylint: disable=R0201
+    def consume(self, event: CWLogEvent):
+        click.echo(event.message, nl=False)

samcli/commands/logs/logs_context.py

@@ -3,13 +3,21 @@
 """
 
 import logging
+
 import boto3
 import botocore
 
 from samcli.commands.exceptions import UserException
-from samcli.lib.logs.fetcher import LogsFetcher
-from samcli.lib.logs.formatter import LogsFormatter, LambdaLogMsgFormatters, JSONMsgFormatter, KeywordHighlighter
-from samcli.lib.logs.provider import LogGroupProvider
+from samcli.commands.logs.console_consumers import CWConsoleEventConsumer
+from samcli.lib.observability.cw_logs.cw_log_formatters import (
+    CWColorizeErrorsFormatter,
+    CWJsonFormatter,
+    CWKeywordHighlighterFormatter,
+    CWPrettyPrintFormatter,
+)
+from samcli.lib.observability.cw_logs.cw_log_group_provider import LogGroupProvider
+from samcli.lib.observability.cw_logs.cw_log_puller import CWLogPuller
+from samcli.lib.observability.observability_info_puller import ObservabilityEventConsumerDecorator
 from samcli.lib.utils.colors import Colored
 from samcli.lib.utils.time import to_utc, parse_date
 
@@ -97,26 +105,20 @@ def __exit__(self, *args):
 
     @property
     def fetcher(self):
-        return LogsFetcher(self._logs_client)
-
-    @property
-    def formatter(self):
-        """
-        Creates and returns a Formatter capable of nicely formatting Lambda function logs
-
-        Returns
-        -------
-        LogsFormatter
-        """
-        formatter_chain = [
-            LambdaLogMsgFormatters.colorize_errors,
-            # Format JSON "before" highlighting the keywords. Otherwise, JSON will be invalid from all the
-            # ANSI color codes and fail to pretty print
-            JSONMsgFormatter.format_json,
-            KeywordHighlighter(self._filter_pattern).highlight_keywords,
-        ]
-
-        return LogsFormatter(self.colored, formatter_chain)
+        return CWLogPuller(
+            logs_client=self._logs_client,
+            consumer=ObservabilityEventConsumerDecorator(
+                mappers=[
+                    CWColorizeErrorsFormatter(self.colored),
+                    CWJsonFormatter(),
+                    CWKeywordHighlighterFormatter(self.colored, self._filter_pattern),
+                    CWPrettyPrintFormatter(self.colored),
+                ],
+                consumer=CWConsoleEventConsumer(),
+            ),
+            cw_log_group=self.log_group_name,
+            resource_name=self._function_name,
+        )
 
     @property
     def start_time(self):