Add Healthchecks monitoring hook "ping_body_limit" option to configure how many bytes of logs to send to the Healthchecks server (#294).

NEWS

@@ -1,4 +1,6 @@
 1.6.1.dev0
+ * #294: Add Healthchecks monitoring hook "ping_body_limit" option to configure how many bytes of
+   logs to send to the Healthchecks server.
  * #402: Remove the error when "archive_name_format" is specified but a retention prefix isn't. 
  * #420: Warn when an unsupported variable is used in a hook command.
  * #528: Improve the error message when a configuration override contains an invalid value.

borgmatic/config/schema.yaml

@@ -892,6 +892,15 @@ properties:
                             Healthchecks ping URL or UUID to notify when a
                             backup begins, ends, or errors.
                         example: https://hc-ping.com/your-uuid-here
+                    ping_body_limit:
+                        type: integer
+                        description: |
+                            Number of bytes of borgmatic logs to send to
+                            Healthchecks, ideally the same as PING_BODY_LIMIT
+                            configured on the Healthchecks server. Set to 0 to
+                            send all logs and disable this truncation. Defaults
+                            to 100000.
+                        example: 200000
                 description: |
                     Configuration for a monitoring integration with
                     Healthchecks. Create an account at https://healthchecks.io

borgmatic/hooks/healthchecks.py

@@ -13,13 +13,14 @@ MONITOR_STATE_TO_HEALTHCHECKS = {
 }
 
 PAYLOAD_TRUNCATION_INDICATOR = '...\n'
-PAYLOAD_LIMIT_BYTES = 100 * 1024 - len(PAYLOAD_TRUNCATION_INDICATOR)
+DEFAULT_PING_BODY_LIMIT_BYTES = 100000
 
 
 class Forgetful_buffering_handler(logging.Handler):
     '''
     A buffering log handler that stores log messages in memory, and throws away messages (oldest
-    first) once a particular capacity in bytes is reached.
+    first) once a particular capacity in bytes is reached. But if the given byte capacity is zero,
+    don't throw away any messages.
     '''
 
     def __init__(self, byte_capacity, log_level):
@@ -36,6 +37,9 @@ class Forgetful_buffering_handler(logging.Handler):
         self.byte_count += len(message)
         self.buffer.append(message)
 
+        if not self.byte_capacity:
+            return
+
         while self.byte_count > self.byte_capacity and self.buffer:
             self.byte_count -= len(self.buffer[0])
             self.buffer.pop(0)
@@ -65,15 +69,19 @@ def format_buffered_logs_for_payload():
     return payload
 
 
-def initialize_monitor(
-    hook_config, config_filename, monitoring_log_level, dry_run
-):  # pragma: no cover
+def initialize_monitor(hook_config, config_filename, monitoring_log_level, dry_run):
     '''
     Add a handler to the root logger that stores in memory the most recent logs emitted. That
     way, we can send them all to Healthchecks upon a finish or failure state.
     '''
+    ping_body_limit = max(
+        hook_config.get('ping_body_limit', DEFAULT_PING_BODY_LIMIT_BYTES)
+        - len(PAYLOAD_TRUNCATION_INDICATOR),
+        0,
+    )
+
     logging.getLogger().addHandler(
-        Forgetful_buffering_handler(PAYLOAD_LIMIT_BYTES, monitoring_log_level)
+        Forgetful_buffering_handler(ping_body_limit, monitoring_log_level)
     )
 
 

tests/unit/hooks/test_healthchecks.py

@@ -12,6 +12,15 @@ def test_forgetful_buffering_handler_emit_collects_log_records():
     assert not handler.forgot
 
 
+def test_forgetful_buffering_handler_emit_collects_log_records_with_zero_byte_capacity():
+    handler = module.Forgetful_buffering_handler(byte_capacity=0, log_level=1)
+    handler.emit(flexmock(getMessage=lambda: 'foo'))
+    handler.emit(flexmock(getMessage=lambda: 'bar'))
+
+    assert handler.buffer == ['foo\n', 'bar\n']
+    assert not handler.forgot
+
+
 def test_forgetful_buffering_handler_emit_forgets_log_records_when_capacity_reached():
     handler = module.Forgetful_buffering_handler(byte_capacity=len('foo\nbar\n'), log_level=1)
     handler.emit(flexmock(getMessage=lambda: 'foo'))
@@ -60,6 +69,43 @@ def test_format_buffered_logs_for_payload_without_handler_produces_empty_payload
     assert payload == ''
 
 
+def test_initialize_monitor_creates_log_handler_with_ping_body_limit():
+    ping_body_limit = 100
+    monitoring_log_level = 1
+
+    flexmock(module).should_receive('Forgetful_buffering_handler').with_args(
+        ping_body_limit - len(module.PAYLOAD_TRUNCATION_INDICATOR), monitoring_log_level
+    ).once()
+
+    module.initialize_monitor(
+        {'ping_body_limit': ping_body_limit}, 'test.yaml', monitoring_log_level, dry_run=False
+    )
+
+
+def test_initialize_monitor_creates_log_handler_with_default_ping_body_limit():
+    monitoring_log_level = 1
+
+    flexmock(module).should_receive('Forgetful_buffering_handler').with_args(
+        module.DEFAULT_PING_BODY_LIMIT_BYTES - len(module.PAYLOAD_TRUNCATION_INDICATOR),
+        monitoring_log_level,
+    ).once()
+
+    module.initialize_monitor({}, 'test.yaml', monitoring_log_level, dry_run=False)
+
+
+def test_initialize_monitor_creates_log_handler_with_zero_ping_body_limit():
+    ping_body_limit = 0
+    monitoring_log_level = 1
+
+    flexmock(module).should_receive('Forgetful_buffering_handler').with_args(
+        ping_body_limit, monitoring_log_level
+    ).once()
+
+    module.initialize_monitor(
+        {'ping_body_limit': ping_body_limit}, 'test.yaml', monitoring_log_level, dry_run=False
+    )
+
+
 def test_ping_monitor_hits_ping_url_for_start_state():
     flexmock(module).should_receive('Forgetful_buffering_handler')
     hook_config = {'ping_url': 'https://example.com'}