I keep receiving this S3 error
A client error (AccessDenied) occurred when calling the ListObjects operation: Access Denied
I've rechecked my credentials and did do some research as well but couldn’t find anything. I edited my bucket policy to add an s3:ListBucket action, but to no avail. When I do so, it just returns a similar message:
A client error (AccessDenied) occurred when calling the ListBuckets operation: Access Denied
Always returns the same error. Any kind of help is appreciated.
I have created a Lambda Python function through AWS Cloud 9 but have hit an issue when trying to write to an S3 bucket from the Lambda Function. When I test in Cloud 9 the Python codes runs fine and writes to the S3 bucket perfectly. When I push this to the Lambda function and it runs I think get the error. This makes me think there is a permission different between the roles used to run the application in Could 9, and that when the Lambda function runs.
The below error is given and I am looking for some advise on what I could be missing, below the error I have described the setup:
[ERROR] ClientError: An error occurred (AccessDenied) when calling the PutObject operation: Access Denied Traceback (most recent call last): File "/var/task/index.py", line 22, in handler s3.Bucket(bucket_name).put_object(Key=s3_path, Body=encoded_string) File "/var/runtime/boto3/resources/factory.py", line 520, in do_action response = action(self, *args, **kwargs) File "/var/runtime/boto3/resources/action.py", line 83, in __call__ response = getattr(parent.meta.client, operation_name)(**params) File "/var/runtime/botocore/client.py", line 320, in _api_call return self._make_api_call(operation_name, kwargs) File "/var/runtime/botocore/client.py", line 623, in _make_api_call raise error_class(parsed_response, operation_name)The code I have is as follows:
import json import datetime from botocore.vendored import requests import boto3 def handler(event, context): print("Start:") response = requests.get('//##########') data = response.json() for i in data: print (i) encoded_string = json.dumps(i).encode("utf-8") bucket_name = "data" file_name = str(i['id']) + ".txt" lambda_path = "/tmp/" + file_name s3_path = "testBucket/" + file_name s3 = boto3.resource("s3") s3.Bucket(bucket_name).put_object(Key=s3_path, Body=encoded_string) ...rest of code ...The .yml file with the necessary permissions is as follows:
The role the Lambda function executes with is as follows: IAM Role
Any advice as to where this could be going wrong. I understand that I need to provide the correct access but I am unsure as to where else I need to specify the correct access (I really do not want to make my S3 public just so my Lambda function can access it). In Lambda it shows that S3 has been added as a resource the functions role has access to but yet receiving the above error.
AWS S3 ListObjects Access Denied error can be resolved easily with these troubleshooting tips by our experts.
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Let’s take a look at how our AWS Support Team is ready to help customers troubleshoot AWS S3 ListObjects Access Denied.
All about AWS S3 ListObjects Access Denied Error
Have you been coming across the following error while trying to access your AWS S3 bucket?
An error occurred (AccessDenied) when calling the ListObjects operation: Access Denied
Each time an AWS S3 sync command is run, it leads to the Amazon S3 listing the source and destination in order to verify the object exists.
In other words, it results in the following API calls: CopyObject, ListObjectsV2, PutObject, and GetObject.
- CopyObject API call for the bucket to bucket operation
- PutObject API for local to bucket operation
- GetObject API for the bucket to local operation
The Access Denied error occurs due to not having the required permissions to perform actions on the bucket. Fortunately, there is an easy resolution AWS S3 ListObjects operation Access Denied error.
How to resolve AWS S3 ListObjects Access Denied
According to our AWS experts, the fix for this specific issue involves configuring the IAM policy.
To begin with, we have to ensure that we have permission to list objects in the bucket as per the IAM and bucket policies if the IAM user or role belongs to another AWS account.
However, if the user or role belongs to the bucket owner’s account, we need permission only from IAM or the bucket policy.
Additionally, our AWS experts suggest checking other policy statements for explicit denial of action.
For instance, here is a sample IAM policy that offers permission to s3:ListBucket
s3:ListBucket- Name of the permission that permits a user to list objects in the bucket.
ListObjectsV2- Name of the API call that lists objects in the bucket.
"Action": "s3:ListBucket", "Effect": "Allow", "Resource": "arn:aws:s3:::AWSDOC-SAMPLE-BUCKET" }] }Moreover, here is a sample bucket policy that offers user arn:aws:iam::202204295674:user/user1 access to s3:ListBucket:
Checking ListObjectV2 permission
If the Request Pays is enabled and our bucket belongs to another user, we have ot check whether the IAM and bucket policies both offer ListObjectsV2 permissions. If yes, verify the sync command syntax. In fact, one of our customers came across the AWS S3 Access Denied ListObjects error due to an incorrect sync command syntax.
Here is a quick look at the sync command syntax when Request Pays is enabled:
aws s3 sync ./ s3://requester-pays-bucket/ --request-payer requesterHowever, if we are still facing the error, it is time to attach a policy that permits ListBucket action on the bucket as well as GetObject action on bucket objects to the IAM user or role with S3 bucket access.
{ "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": [ "s3:GetObject" ], "Resource": [ "arn:aws:s3:::OUR_BUCKET/*" ] }, { "Effect": "Allow", "Action": [ "s3:ListBucket" ], "Resource": [ "arn:aws:s3:::OUR_BUCKET" ] } ] }Alternatively, our AWS experts suggest verifying that the policy does not restrict access to GetObject or ListObject action. Furthermore, check if there is a condition that permits only a particular IP range to access bucket objects.
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Conclusion
In a nutshell, our skilled AWS Support Engineers at Bobcares demonstrated how to troubleshoot and resolve AWS S3 ListObjects Access Denied error.
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