User permissions to authorize AWS CLI via metadata inside EC2 - linux

I'm trying to get access from my EC2 instance to S3 bucket via CLI, but I cannot do this with my user.
The instance is build with ansible and got 2 users one is ec2-user and the other test-user. When connecting to the instance via SSH and user ec2-user I can easily download the files from s3 bucket, but when logging with the second user I got An error occurred (403) when calling the HeadObject operation: Forbidden.
What permissions should I gave the test-user to be able to get data from bucket?

Based on the comments.
The instance using instance role, thus both users have equal access to s3. However, the access was failing for test-user since the user was using different IAM credentials then those from instance role.
The credentials came from env variables or .aws/ which have higher priority then instance role, resulting in access deny.

Related

How to change aws config profile in AWS sdk nodejs

I have configured cross account s3 bucket access from a ec2 instance. when I login to the aws ec2 server and run aws cli command to get s3 bucket data that have created in the another aws account, its work properly. please find below command.
aws s3 ls s3://test-bucket-name --profile demo
But, I need to do this using nodejs sdk. I have a application that run on ec2. This application needs to access this bucket data through the application. Is there any way to access this bucket data from application using nodejs?
Launch the EC2 instance with an IAM role in account 1 that has permission to assume an IAM role in account 2. That second role provides S3 access to the relevant bucket/objects in account 2.
Code using the AWS JavaScript SDK will automatically get credentials for IAM role 1. Your code can then assume IAM role 2, get credentials, and then access the cross-account S3 bucket.

Uploading a file through boto3 upload_file api to AWS S3 bucket gives "Anonymous users cannot initiate multipart uploads. Please authenticate." error

I have a file of around 16mb in size and am using python boto3 upload_file api to upload this file into the S3 bucket. However, I believe the API is internally choosing multipart upload and gives me an "Anonymous users cannot initiate multipart upload" error.
In some of the runs of the application, the file generated may be smaller (few KBs) in size.
What's the best way to handle this scenario in general or fix the error I mentioned above?
I currently have a Django application that generates a file when run and uploads this file directly into an S3 bucket.
Ok, so unless you've opened your S3 bucket up for the world to upload to (which is very much NOT recommended), it sounds like you need to setup the permissions for access to your S3 bucket correctly.
How to do that will vary a little depending on how you're running this application - so let's cover off a few options - in all cases you will need to do two things:
Associate your script with an IAM Principal (an IAM User or an IAM Role depending on where / how this script is being run).
Add permissions for that principal to access the bucket (this can be accomplished either through an IAM Policy, or via the S3 Bucket Policy)
Lambda Function - You'll need to create an IAM Role for your application and associate it with your Lambda function. Boto3 should be able to assume this role transparently for you once configured.
EC2 Instance or ECS Task - You'll need to create an IAM Role for your application and associate it with your EC2 instance/ECS Task. Boto3 will be able to access the credentials for the role via instance metadata and should automatically assume the role.
Local Workstation Script - If you're running this script from your local workstation, then boto3 should be able to find and use the credentials you've setup for the AWS CLI. If those aren't the credentials you want to use you'll need to generate an access key and secret access key (be careful how you secure these if you go this route, and definitely follow least privilege).
Now, once you've got your principal you can either attach an IAM policy that grants Allow permissions to upload to the bucket to the IAM User or Role, or you can add a clause to the Bucket Policy that grants that IAM User or Role access. You only need to do one of these.
Multi-part uploads are performed via the same S3:PutObject call as single part uploads (though if your files are small I'd be surprised it was using multi-part for them). If you're using KMS one small trick to be aware of is that you need permission to use the KMS key for both Encrypt and Decrypt permissions if encrypting a multi-part upload.

How to use AWS IAM in nodejs application on fargate scheduled task

I am a student who is trying to make a scheduled task using nodejs(typescript).
The task is to access S3 and fetch the object and then do some stuff with it.
However, I am having hard time trying to figure out loading the credentials. I am trying to do it without writing out the ClientConfiguration, which has the space for putting in accesskey, secretAccesskey. Hint or clue would be nice. Thank you for your time.
You can configure an IAM tole for your fargate task/service and assign permission to the role. In this way you do not have to hardcode the aws access credentials in side the code.
There are two types of IAM roles associated with ECS.
task execution role
gives permission to pull/push container images from the register and publish logs to cloudwatch.
task role
gives permission to access aws services. you should set up assign s3 permissions to this particular role.
https://docs.aws.amazon.com/AmazonECS/latest/developerguide/create-task-definition.html
Hope this helps.

How to connect IAM login name with an EC2 instance?

I am using the boto3 Python3 module provided by AWS. I'm able to extract the security key name and the various tags associated with an EC2 instance. Unfortunately, none of that information tells me who created the instance.
Is there a way to use AWS IAM to see what active instances were created by a user?

Running EMR Spark With Multiple S3 Accounts

I have an EMR Spark Job that needs to read data from S3 on one account and write to another.
I split my job into two steps.
read data from the S3 (no credentials required because my EMR cluster is in the same account).
read data in the local HDFS created by step 1 and write it to an S3 bucket in another account.
I've attempted setting the hadoopConfiguration:
sc.hadoopConfiguration.set("fs.s3n.awsAccessKeyId", "<your access key>")
sc.hadoopConfiguration.set("fs.s3n.awsSecretAccessKey","<your secretkey>")
And exporting the keys on the cluster:
$ export AWS_SECRET_ACCESS_KEY=
$ export AWS_ACCESS_KEY_ID=
I've tried both cluster and client mode as well as spark-shell with no luck.
Each of them returns an error:
ERROR ApplicationMaster: User class threw exception: com.amazon.ws.emr.hadoop.fs.shaded.com.amazonaws.services.s3.model.AmazonS3Exception:
Access Denied
The solution is actually quite simple.
Firstly, EMR clusters have two roles:
A service role (EMR_DefaultRole) that grants permissions to the EMR service (eg for launching Amazon EC2 instances)
An EC2 role (EMR_EC2_DefaultRole) that is attached to EC2 instances launched in the cluster, giving them access to AWS credentials (see Using an IAM Role to Grant Permissions to Applications Running on Amazon EC2 Instances)
These roles are explained in: Default IAM Roles for Amazon EMR
Therefore, each EC2 instance launched in the cluster is assigned the EMR_EC2_DefaultRole role, which makes temporary credentials available via the Instance Metadata service. (For an explanation of how this works, see: IAM Roles for Amazon EC2.) Amazon EMR nodes use these credentials to access AWS services such as S3, SNS, SQS, CloudWatch and DynamoDB.
Secondly, you will need to add permissions to the Amazon S3 bucket in the other account to permit access via the EMR_EC2_DefaultRole role. This can be done by adding a bucket policy to the S3 bucket (here named other-account-bucket) like this:
{
"Id": "Policy1",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Stmt1",
"Action": "s3:*",
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::other-account-bucket",
"arn:aws:s3:::other-account-bucket/*"
],
"Principal": {
"AWS": [
"arn:aws:iam::ACCOUNT-NUMBER:role/EMR_EC2_DefaultRole"
]
}
}
]
}
This policy grants all S3 permissions (s3:*) to the EMR_EC2_DefaultRole role that belongs to the account matching the ACCOUNT-NUMBER in the policy, which should be the account in which the EMR cluster was launched. Be careful when granting such permissions -- you might want to grant permissions only to GetObject rather than granting all S3 permissions.
That's all! The bucket in the other account will now accept requests from the EMR nodes because they are using the EMR_EC2_DefaultRole role.
Disclaimer: I tested the above by creating a bucket in Account-A and assigning permissions (as shown above) to a role in Account-B. An EC2 instance was launched in Account-B with that role. I was able to access the bucket from the EC2 instance via the AWS Command-Line Interface (CLI). I did not test it within EMR, however it should work the same way.
Using spark you can also use assume role to access an s3 bucket in another account but using an IAM Role in the other account. This makes it easier for the other account owner to manage the permissions provided to the spark job. Managing access via s3 bucket policies can be a pain as access rights are distributed to multiple locations rather than all contained within a single IAM role.
Here is the hadoopConfiguration:
"fs.s3a.credentialsType" -> "AssumeRole",
"fs.s3a.stsAssumeRole.arn" -> "arn:aws:iam::<<AWSAccount>>:role/<<crossaccount-role>>",
"fs.s3a.impl" -> "com.databricks.s3a.S3AFileSystem",
"spark.hadoop.fs.s3a.server-side-encryption-algorithm" -> "aws:kms",
"spark.hadoop.fs.s3a.server-side-encryption-kms-master-key-id" -> "arn:aws:kms:ap-southeast-2:<<AWSAccount>>:key/<<KMS Key ID>>"
External IDs can also be used as a passphrase:
"spark.hadoop.fs.s3a.stsAssumeRole.externalId" -> "GUID created by other account owner"
We were using databricks for the above have not tried using EMR yet.
I believe you need to assign an IAM role to your compute nodes (you probably already have done this), then grant cross-account access to that role via IAM on the "Remote" account. See http://docs.aws.amazon.com/IAM/latest/UserGuide/tutorial_cross-account-with-roles.html for the details.
For controlling access of the resources, generally IAM roles are managed as a standard practice. Assume roles are used when you want to access resources in a different account. If you or your organisation follow the same then you should follow https://aws.amazon.com/blogs/big-data/securely-analyze-data-from-another-aws-account-with-emrfs/.
The basic idea here is to use a credentials provider with which the access is obtained by EMRFS to access objects in S3 buckets.
You can go one step further and make the ARN for STS and buckets parameterized for the JAR created in this blog.

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