refactor: Improve error handling for exception

ViBiOh · ViBiOh · commit 43bec96219c5 · 2025-10-21T15:52:44.000+02:00
Signed-off-by: Vincent Boutour &lt;vincent.boutour@datadoghq.com&gt;
diff --git a/aws/logs_monitoring/caching/base_tags_cache.py b/aws/logs_monitoring/caching/base_tags_cache.py
@@ -60,9 +60,9 @@ def write_cache_to_s3(self, data):
                 DD_S3_BUCKET_NAME, self.get_cache_name_with_prefix()
             )
             s3_object.put(Body=(bytes(json.dumps(data).encode("UTF-8"))))
-        except ClientError:
+        except ClientError as e:
             send_forwarder_internal_metrics("s3_cache_write_failure")
-            self.logger.debug("Unable to write new cache to S3", exc_info=True)
+            self.logger.debug(f"Unable to write new cache to S3: {e}", exc_info=True)
 
     def acquire_s3_cache_lock(self):
         """Acquire cache lock"""
@@ -76,16 +76,16 @@ def acquire_s3_cache_lock(self):
             last_modified_unix_time = get_last_modified_time(file_content)
             if last_modified_unix_time + DD_S3_CACHE_LOCK_TTL_SECONDS >= time():
                 return False
-        except Exception:
-            self.logger.debug("Unable to get cache lock file")
+        except Exception as e:
+            self.logger.debug(f"Unable to get cache lock file: {e}")
 
         # lock file doesn't exist, create file to acquire lock
         try:
             cache_lock_object.put(Body=(bytes("lock".encode("UTF-8"))))
             send_forwarder_internal_metrics("s3_cache_lock_acquired")
             self.logger.debug("S3 cache lock acquired")
-        except ClientError:
-            self.logger.debug("Unable to write S3 cache lock file", exc_info=True)
+        except ClientError as e:
+            self.logger.debug(f"Unable to write S3 cache lock file: {e}", exc_info=True)
             return False
 
         return True
@@ -99,9 +99,9 @@ def release_s3_cache_lock(self):
             cache_lock_object.delete()
             send_forwarder_internal_metrics("s3_cache_lock_released")
             self.logger.debug("S3 cache lock released")
-        except ClientError:
+        except ClientError as e:
             send_forwarder_internal_metrics("s3_cache_lock_release_failure")
-            self.logger.debug("Unable to release S3 cache lock", exc_info=True)
+            self.logger.debug(f"Unable to release S3 cache lock: {e}", exc_info=True)
 
     def get_cache_from_s3(self):
         """Retrieves tags cache from s3 and returns the body along with
@@ -113,9 +113,9 @@ def get_cache_from_s3(self):
             file_content = cache_object.get()
             tags_cache = json.loads(file_content["Body"].read().decode("utf-8"))
             last_modified_unix_time = get_last_modified_time(file_content)
-        except:
+        except Exception as e:
             send_forwarder_internal_metrics("s3_cache_fetch_failure")
-            self.logger.debug("Unable to fetch cache from S3", exc_info=True)
+            self.logger.debug(f"Unable to fetch cache from S3: {e}", exc_info=True)
             return {}, -1
 
         return tags_cache, last_modified_unix_time
diff --git a/aws/logs_monitoring/caching/cloudwatch_log_group_cache.py b/aws/logs_monitoring/caching/cloudwatch_log_group_cache.py
@@ -103,10 +103,10 @@ def _get_log_group_tags_from_cache(self, cache_file_name):
             )
             tags_cache = json.loads(response.get("Body").read().decode("utf-8"))
             last_modified_unix_time = int(response.get("LastModified").timestamp())
-        except Exception:
+        except Exception as e:
             send_forwarder_internal_metrics("loggroup_cache_fetch_failure")
             self.logger.exception(
-                "Failed to get log group tags from cache", exc_info=True
+                f"Failed to get log group tags from cache: {e}", exc_info=True
             )
             return None, -1
 
@@ -120,10 +120,10 @@ def _update_log_group_tags_cache(self, log_group, tags):
                 Key=cache_file_name,
                 Body=(bytes(json.dumps(tags).encode("UTF-8"))),
             )
-        except Exception:
+        except Exception as e:
             send_forwarder_internal_metrics("loggroup_cache_write_failure")
             self.logger.exception(
-                "Failed to update log group tags cache", exc_info=True
+                f"Failed to update log group tags cache: {e}", exc_info=True
             )
 
     def _is_expired(self, last_modified):
@@ -150,8 +150,8 @@ def _get_log_group_tags(self, log_group_arn):
             response = self.cloudwatch_logs_client.list_tags_for_resource(
                 resourceArn=log_group_arn
             )
-        except Exception:
-            self.logger.exception("Failed to get log group tags", exc_info=True)
+        except Exception as e:
+            self.logger.exception(f"Failed to get log group tags: {e}", exc_info=True)
         formatted_tags = None
         if response is not None:
             formatted_tags = [
diff --git a/aws/logs_monitoring/caching/lambda_cache.py b/aws/logs_monitoring/caching/lambda_cache.py
@@ -43,8 +43,8 @@ def build_tags_cache(self):
 
         except ClientError as e:
             self.logger.exception(
-                "Encountered a ClientError when trying to fetch tags. You may need to give "
-                "this Lambda's role the 'tag:GetResources' permission"
+                f"Failed to fetch Lambda tags: {e}. "
+                "Add 'tag:GetResources' permission to the Forwarder's IAM role."
             )
             additional_tags = [
                 f"http_status_code:{e.response['ResponseMetadata']['HTTPStatusCode']}"
diff --git a/aws/logs_monitoring/caching/s3_tags_cache.py b/aws/logs_monitoring/caching/s3_tags_cache.py
@@ -42,7 +42,7 @@ def build_tags_cache(self):
         except ClientError as e:
             self.logger.exception(
                 "Encountered a ClientError when trying to fetch tags. You may need to give "
-                "this Lambda's role the 'tag:GetResources' permission"
+                f"this Lambda's role the 'tag:GetResources' permission: {e}"
             )
             additional_tags = [
                 f"http_status_code:{e.response['ResponseMetadata']['HTTPStatusCode']}"
diff --git a/aws/logs_monitoring/caching/step_functions_cache.py b/aws/logs_monitoring/caching/step_functions_cache.py
@@ -51,7 +51,7 @@ def build_tags_cache(self):
         except ClientError as e:
             self.logger.exception(
                 "Encountered a ClientError when trying to fetch tags. You may need to give "
-                "this Lambda's role the 'tag:GetResources' permission"
+                f"this Lambda's role the 'tag:GetResources' permission: {e}"
             )
             additional_tags = [
                 f"http_status_code:{e.response['ResponseMetadata']['HTTPStatusCode']}"
diff --git a/aws/logs_monitoring/forwarder.py b/aws/logs_monitoring/forwarder.py
@@ -116,8 +116,10 @@ def _forward_logs(self, logs, key=None):
             for batch in batcher.batch(logs_to_forward):
                 try:
                     client.send(batch)
-                except Exception:
-                    logger.exception(f"Exception while forwarding log batch {batch}")
+                except Exception as e:
+                    logger.exception(
+                        f"Exception while forwarding log batch {batch}: {e}"
+                    )
                     failed_logs.extend(batch)
                 else:
                     if logger.isEnabledFor(logging.DEBUG):
@@ -142,9 +144,9 @@ def _forward_metrics(self, metrics, key=None):
         for metric in metrics:
             try:
                 send_log_metric(metric)
-            except Exception:
+            except Exception as e:
                 logger.exception(
-                    f"Exception while forwarding metric {json.dumps(metric)}"
+                    f"Exception while forwarding metric {json.dumps(metric)}: {e}"
                 )
                 failed_metrics.append(metric)
             else:
@@ -168,9 +170,9 @@ def _forward_traces(self, traces, key=None):
         try:
             serialized_trace_paylods = json.dumps(traces)
             self.trace_connection.send_traces(serialized_trace_paylods)
-        except Exception:
+        except Exception as e:
             logger.exception(
-                f"Exception while forwarding traces {serialized_trace_paylods}"
+                f"Exception while forwarding traces {serialized_trace_paylods}: {e}"
             )
             if DD_STORE_FAILED_EVENTS and not key:
                 self.storage.store_data(RetryPrefix.TRACES, traces)
diff --git a/aws/logs_monitoring/lambda_function.py b/aws/logs_monitoring/lambda_function.py
@@ -4,41 +4,46 @@
 # Copyright 2021 Datadog, Inc.
 
 import json
-import os
-import boto3
 import logging
-import requests
+import os
 from hashlib import sha1
 
-from datadog_lambda.wrapper import datadog_lambda_wrapper
+import boto3
+import requests
 from datadog import api
-from enhanced_lambda_metrics import parse_and_submit_enhanced_metrics
-from steps.parsing import parse
-from steps.enrichment import enrich
-from steps.transformation import transform
-from steps.splitting import split
+from datadog_lambda.wrapper import datadog_lambda_wrapper
+
 from caching.cache_layer import CacheLayer
+from enhanced_lambda_metrics import parse_and_submit_enhanced_metrics
 from forwarder import Forwarder
 from settings import (
+    DD_ADDITIONAL_TARGET_LAMBDAS,
     DD_API_KEY,
-    DD_SKIP_SSL_VALIDATION,
     DD_API_URL,
     DD_FORWARDER_VERSION,
-    DD_ADDITIONAL_TARGET_LAMBDAS,
     DD_RETRY_KEYWORD,
+    DD_SITE,
+    DD_SKIP_SSL_VALIDATION,
 )
+from steps.enrichment import enrich
+from steps.parsing import parse
+from steps.splitting import split
+from steps.transformation import transform
 
 logger = logging.getLogger()
 logger.setLevel(logging.getLevelName(os.environ.get("DD_LOG_LEVEL", "INFO").upper()))
 
 # DD_API_KEY must be set
 if DD_API_KEY == "<YOUR_DATADOG_API_KEY>" or DD_API_KEY == "":
-    raise Exception("Missing Datadog API key")
+    raise Exception(
+        "Missing Datadog API key. Set DD_API_KEY environment variable. "
+        "See: https://docs.datadoghq.com/serverless/forwarder/"
+    )
 # Check if the API key is the correct number of characters
 if len(DD_API_KEY) != 32:
     raise Exception(
-        "The API key is not the expected length. "
-        "Please confirm that your API key is correct"
+        f"Invalid Datadog API key format. Expected 32 characters, received {len(DD_API_KEY)}. "
+        f"Verify your API key at https://app.{DD_SITE}/organization-settings/api-keys"
     )
 # Validate the API key
 logger.debug("Validating the Datadog API key")
@@ -57,7 +62,11 @@
         timeout=10,
     )
     if not validation_res.ok:
-        raise Exception("The API key is not valid.")
+        raise Exception(
+            f"Datadog API key validation failed (HTTP {validation_res.status_code}). "
+            f"Verify your API key is correct and DD_SITE matches your Datadog account region (current: {DD_SITE}). "
+            "See: https://docs.datadoghq.com/getting_started/site/"
+        )
 
 # Force the layer to use the exact same API key and host as the forwarder
 api._api_key = DD_API_KEY
diff --git a/aws/logs_monitoring/logs/datadog_http_client.py b/aws/logs_monitoring/logs/datadog_http_client.py
@@ -95,8 +95,8 @@ def send(self, logs):
         """
         try:
             data = self._scrubber.scrub("[{}]".format(",".join(logs)))
-        except ScrubbingException:
-            raise Exception("could not scrub the payload")
+        except ScrubbingException as e:
+            raise Exception(f"could not scrub the payload: {e}")
         if DD_USE_COMPRESSION:
             data = compress_logs(data, DD_COMPRESSION_LEVEL)
 
diff --git a/aws/logs_monitoring/logs/datadog_matcher.py b/aws/logs_monitoring/logs/datadog_matcher.py
@@ -44,5 +44,5 @@ def match(self, log):
 
             return True
 
-        except ScrubbingException:
-            raise Exception("could not filter the payload")
+        except Exception as e:
+            raise Exception(f"Failed to filter log: {e}")
diff --git a/aws/logs_monitoring/logs/helpers.py b/aws/logs_monitoring/logs/helpers.py
@@ -34,16 +34,16 @@ def compileRegex(rule, pattern):
     if pattern == "":
         # If pattern is an empty string, raise exception
         raise Exception(
-            "No pattern provided:\nAdd pattern or remove {} environment variable".format(
-                rule
-            )
+            f"Empty pattern for {rule}. Set a valid regex pattern or remove the {rule} environment variable."
         )
     try:
         return re.compile(pattern)
-    except Exception:
+    except re.error as e:
         raise Exception(
-            "could not compile {} regex with pattern: {}".format(rule, pattern)
+            f"Invalid regex pattern for {rule}: '{pattern}'. Regex error: {e}"
         )
+    except Exception as e:
+        raise Exception(f"Failed to compile {rule} regex pattern '{pattern}': {e}")
 
 
 def add_retry_tag(log):
diff --git a/aws/logs_monitoring/retry/storage.py b/aws/logs_monitoring/retry/storage.py
@@ -40,14 +40,14 @@ def store_data(self, prefix, data):
             self.s3_client.put_object(
                 Bucket=self.bucket_name, Key=key, Body=serialized_data
             )
-        except ClientError:
-            logger.error(f"Failed to store retry data for prefix {prefix}")
+        except ClientError as e:
+            logger.error(f"Failed to store retry data for prefix {prefix}: {e}")
 
     def delete_data(self, key):
         try:
             self.s3_client.delete_object(Bucket=self.bucket_name, Key=key)
-        except ClientError:
-            logger.error(f"Failed to delete retry data for key {key}")
+        except ClientError as e:
+            logger.error(f"Failed to delete retry data for key {key}: {e}")
 
     def _list_keys(self, prefix):
         key_prefix = self._get_key_prefix(prefix)
@@ -68,8 +68,8 @@ def _fetch_data_for_key(self, key):
             body = response.get("Body")
             data = body.read()
             return self._deserialize(data)
-        except ClientError:
-            logger.error(f"Failed to fetch retry data for key {key}")
+        except ClientError as e:
+            logger.error(f"Failed to fetch retry data for key {key}: {e}")
             return None
         except Exception as e:
             logger.error(
diff --git a/aws/logs_monitoring/steps/enrichment.py b/aws/logs_monitoring/steps/enrichment.py
@@ -152,9 +152,9 @@ def extract_ddtags_from_message(event):
                 message_dict = json.loads(event["message"])
                 extracted_ddtags = message_dict.pop(DD_CUSTOM_TAGS)
                 event["message"] = json.dumps(message_dict)
-            except Exception:
+            except Exception as e:
                 if logger.isEnabledFor(logging.DEBUG):
-                    logger.debug(f"Failed to extract ddtags from: {event}")
+                    logger.debug(f"Failed to extract ddtags from: {event}: {e}")
                 return
 
         # strip and cleanup spaces from extracted tags:
@@ -191,8 +191,8 @@ def extract_host_from_cloudtrails(event):
         if isinstance(message, str):
             try:
                 message = json.loads(message)
-            except json.JSONDecodeError:
-                logger.debug("Failed to decode cloudtrail message")
+            except json.JSONDecodeError as e:
+                logger.debug(f"Failed to decode cloudtrail message: {e}")
                 return
 
         # deal with s3 input type events
diff --git a/aws/logs_monitoring/steps/handlers/aws_attributes.py b/aws/logs_monitoring/steps/handlers/aws_attributes.py
@@ -60,5 +60,5 @@ def set_account_region(self, arn):
             parts = arn.split(":")
             self.account = parts[4]
             self.region = parts[3]
-        except Exception:
-            raise Exception("Failed to parse account and region from ARN")
+        except Exception as e:
+            raise Exception(f"Failed to parse account and region from ARN: {e}")

Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ def build_tags_cache(self):`
`42`	`42`	`except ClientError as e:`
`43`	`43`	`self.logger.exception(`
`44`	`44`	`"Encountered a ClientError when trying to fetch tags. You may need to give "`
`45`		`- "this Lambda's role the 'tag:GetResources' permission"`
	`45`	`+ f"this Lambda's role the 'tag:GetResources' permission: {e}"`
`46`	`46`	`)`
`47`	`47`	`additional_tags = [`
`48`	`48`	`f"http_status_code:{e.response['ResponseMetadata']['HTTPStatusCode']}"`
Original file line number	Diff line number	Diff line change
`@@ -51,7 +51,7 @@ def build_tags_cache(self):`
`51`	`51`	`except ClientError as e:`
`52`	`52`	`self.logger.exception(`
`53`	`53`	`"Encountered a ClientError when trying to fetch tags. You may need to give "`
`54`		`- "this Lambda's role the 'tag:GetResources' permission"`
	`54`	`+ f"this Lambda's role the 'tag:GetResources' permission: {e}"`
`55`	`55`	`)`
`56`	`56`	`additional_tags = [`
`57`	`57`	`f"http_status_code:{e.response['ResponseMetadata']['HTTPStatusCode']}"`