From e1951c0588a4e31340263404c4a94cdd02945c2c Mon Sep 17 00:00:00 2001
From: Shinji Matsumoto <s.kawagt@gmail.com>
Date: Thu, 13 Feb 2020 01:10:44 +0900
Subject: [PATCH] feat(deploy): Efficient deploy log fetching (#1768)

---
 samcli/lib/deploy/deployer.py          | 12 +++++
 tests/unit/lib/deploy/test_deployer.py | 72 ++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)

diff --git a/samcli/lib/deploy/deployer.py b/samcli/lib/deploy/deployer.py
index d5776574ac..6a5b3582a2 100644
--- a/samcli/lib/deploy/deployer.py
+++ b/samcli/lib/deploy/deployer.py
@@ -338,10 +338,14 @@ def describe_stack_events(self, stack_name, time_stamp_marker, **kwargs):
                 paginator = self._client.get_paginator("describe_stack_events")
                 response_iterator = paginator.paginate(StackName=stack_name)
                 stack_status = describe_stacks_resp["Stacks"][0]["StackStatus"]
+                latest_time_stamp_marker = time_stamp_marker
                 for event_items in response_iterator:
                     for event in event_items["StackEvents"]:
                         if event["EventId"] not in events and utc_to_timestamp(event["Timestamp"]) > time_stamp_marker:
                             events.add(event["EventId"])
+                            latest_time_stamp_marker = max(
+                                latest_time_stamp_marker, utc_to_timestamp(event["Timestamp"])
+                            )
                             row_color = self.deploy_color.get_stack_events_status_color(status=event["ResourceStatus"])
                             pprint_columns(
                                 columns=[
@@ -357,6 +361,14 @@ def describe_stack_events(self, stack_name, time_stamp_marker, **kwargs):
                                 columns_dict=DESCRIBE_STACK_EVENTS_DEFAULT_ARGS.copy(),
                                 color=row_color,
                             )
+                        # Skip already shown old event entries
+                        elif utc_to_timestamp(event["Timestamp"]) <= time_stamp_marker:
+                            time_stamp_marker = latest_time_stamp_marker
+                            break
+                    else:  # go to next loop if not break from inside loop
+                        time_stamp_marker = latest_time_stamp_marker  # update marker if all events are new
+                        continue
+                    break  # reached here only if break from inner loop!
 
                 if self._check_stack_complete(stack_status):
                     stack_change_in_progress = False
diff --git a/tests/unit/lib/deploy/test_deployer.py b/tests/unit/lib/deploy/test_deployer.py
index 592585bc26..0cadbe5404 100644
--- a/tests/unit/lib/deploy/test_deployer.py
+++ b/tests/unit/lib/deploy/test_deployer.py
@@ -364,6 +364,78 @@ def test_describe_stack_events(self, patched_time):
 
         self.deployer.describe_stack_events("test", time.time() - 1)
 
+    @patch("time.sleep")
+    @patch("samcli.lib.deploy.deployer.pprint_columns")
+    def test_describe_stack_events_skip_old_event(self, patched_pprint_columns, patched_time):
+        current_timestamp = datetime.utcnow()
+
+        self.deployer._client.describe_stacks = MagicMock(
+            side_effect=[
+                {"Stacks": [{"StackStatus": "CREATE_IN_PROGRESS"}]},
+                {"Stacks": [{"StackStatus": "CREATE_IN_PROGRESS"}]},
+                {"Stacks": [{"StackStatus": "CREATE_COMPLETE_CLEANUP_IN_PROGRESS"}]},
+                {"Stacks": [{"StackStatus": "CREATE_COMPLETE"}]},
+            ]
+        )
+        sample_events = [
+            {
+                "StackEvents": [
+                    {
+                        "EventId": str(uuid.uuid4()),
+                        "Timestamp": current_timestamp,
+                        "ResourceStatus": "CREATE_IN_PROGRESS",
+                        "ResourceType": "s3",
+                        "LogicalResourceId": "mybucket",
+                    }
+                ]
+            },
+            {
+                "StackEvents": [
+                    {
+                        "EventId": str(uuid.uuid4()),
+                        "Timestamp": current_timestamp + timedelta(seconds=10),
+                        "ResourceStatus": "CREATE_IN_PROGRESS",
+                        "ResourceType": "kms",
+                        "LogicalResourceId": "mykms",
+                    }
+                ]
+            },
+            {
+                "StackEvents": [
+                    {
+                        "EventId": str(uuid.uuid4()),
+                        "Timestamp": current_timestamp + timedelta(seconds=20),
+                        "ResourceStatus": "CREATE_COMPLETE",
+                        "ResourceType": "s3",
+                        "LogicalResourceId": "mybucket",
+                    }
+                ]
+            },
+            {
+                "StackEvents": [
+                    {
+                        "EventId": str(uuid.uuid4()),
+                        "Timestamp": current_timestamp + timedelta(seconds=30),
+                        "ResourceStatus": "CREATE_COMPLETE",
+                        "ResourceType": "kms",
+                        "LogicalResourceId": "mykms",
+                    }
+                ]
+            },
+        ]
+        invalid_event = {"StackEvents": [{}]}  # if deployer() loop read this, KeyError would raise
+        self.deployer._client.get_paginator = MagicMock(
+            side_effect=[
+                MockPaginator([sample_events[0]]),
+                MockPaginator([sample_events[1], sample_events[0], invalid_event]),
+                MockPaginator([sample_events[2], sample_events[1], invalid_event]),
+                MockPaginator([sample_events[3], sample_events[2], invalid_event]),
+            ]
+        )
+
+        self.deployer.describe_stack_events("test", time.time() - 1)
+        self.assertEqual(patched_pprint_columns.call_count, 4)
+
     @patch("samcli.lib.deploy.deployer.math")
     @patch("time.sleep")
     def test_describe_stack_events_exceptions(self, patched_time, patched_math):