PermissonSet vs IAM policy - different behavior - amazon-web-services

If I apply below policy to IAM role, it works fine and lets user create ec2 instances as long as they provide Project tag. But if I apply it as PermissionSet, it prevents users from creating ec2 instance even though they specified Project tag.
Here is the how the policy looks like:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "DenyEC2CreationWithoutProjectTag",
"Effect": "Deny",
"Action": "ec2:RunInstances",
"Resource": [
"arn:aws:ec2:*:*:instance/*"
],
"Condition": {
"StringNotEquals": {
"aws:RequestTag/Project": "*"
}
}
}
]
}
What am I missing here?

Related

restrict aws iam user to a specific region (eu-west-1)

I'm trying to create a policy in which the user exam can access only to the region eu-west-1.
I tried to find a solution but didn't found the right one.
the policy looks something like this:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "*",
"Resource": "user_arn",
"Condition": {
"StringEquals": {
"aws:RequestedRegion": "eu-west-1"
}
}
}
]
}
but it does not seem to work no matter what I do.
what is the best way to do so that the user can do whatever he wants but only in this region?
found a solution
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "ec2:*",
"Resource": "*",
"Condition": {
"StringEquals": {
"aws:RequestedRegion": "eu-west-1"
}
}
}
]
}
This should work as well, however you are granting full access to EC2 limited to one region. In the example below you "deny" any ec2 action outside the region or regions defined below, however you are not granting any privileges (they should be assigned in a separate policy or use an Allow statement. Normally this is used as an SCP in AWS organizations,a and you jusy deny action "*", to force all users to create resources only in the designated regions, and deny any API action in regions not authorized.
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Deny",
"Action": "ec2:*",
"Resource": "*",
"Condition": {
"StringNotEquals": {
"aws:RequestedRegion": "eu-west-1"
}
}
}
]

AWS SCP for EC2 type

I want to allow users only to create t2.micro/small/medium for development and allow them to use only spot instances. Have created IAM policy to restrict type/size of instances. In addition I want to put restriction on "on-demand" instances (team MUST opt for spot instances only). What is the cleaner way of achieving it?
allow full access with the account
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "limitedSize",
"Effect": "Deny",
"Action": [
"ec2:RunInstances",
"cloudwatch:DescribeAlarms"
],
"Resource": [
"arn:aws:ec2:*:*:instance/*"
],
"Condition": {
"ForAnyValue:StringNotLike": {
"ec2:InstanceType": [
"t3.*",
"t2.*"
]
}
}
}
]
}
Try AWS Service Catalog.. that is the exact service which can help u here.
Use the ec2:InstanceMarketType condition key in your IAM policy.
Example (untested):
{
"Version": "2012-10-17",
"Statement": {
"Effect": "Allow",
"Action": "*",
"Resource": "*",
"Condition": {
"StringEquals": {
"ec2:InstanceMarketType": "spot"
}
}
}
}
References:
Condition Keys for EC2
EC2 Condition Key Example
Another SO Question

AWS IAM EC2 policy limited to originating instance

I'm working on a setup where I need to terminate AWS instances because of inactivity (i.e. nothing new in web-server access logs since a period of time). Those instances are testing instances and are created automatically by CI/CD software.
I would like those instances to identify themselves that they become abandoned and terminate themselves. I want to assign a generic iam-role to each of them that will only allow the instance the termination of itself and not the peer instances.
So far I've been here:
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ExamplePolicies_EC2.html
https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_variables.html
https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_variables.html#policy-vars-wheretouse
https://www.reddit.com/r/aws/comments/4gglxk/iam_policy_to_allow_ec2_instance_to_only_query/
https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_examples_iam_mfa-selfmanage.html
And figured out that there are 2 variables available in policies:
ec2-instance-id
ec2:SourceInstanceARN
I came up with few variations of my role policy but none of them work:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": "ec2:TerminateInstances",
"Resource": "*",
"Condition": {
"ArnEquals": {
"ec2:SourceInstanceARN": "arn:aws:ec2:*:*:instance/${ec2-instance-id}"
}
}
}
]
}
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": "ec2:TerminateInstances",
"Resource": "arn:aws:ec2:*:*:instance/${ec2-instance-id}"
}
]
}
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": "ec2:TerminateInstances",
"Resource": "${ec2:SourceInstanceARN}"
}
]
}
Is it actually possible to achieve the desired behavior, i.e. to only allow instance to perform specific operation on itself (e.g. Termination)?
UPDATE:
I do know that I can work with tags, that is what I'm doing meanwhile, but that means that all tagged instances can terminate their peers. That is a bit too loose restriction, I'd like to really limit it to the instance it
AWS IAM: Allow EC2 instance to stop itself
IAM policy to allow EC2 instance API access only to modify itself
You were close with your condition. The trick is to compare instance ARN with ec2:sourceInstanceARN:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": [
"ec2:DeleteTags",
"ec2:DescribeTags",
"ec2:CreateTags",
"ec2:TerminateInstances",
"ec2:StopInstances"
],
"Resource": "*",
"Condition": {
"StringEquals": {
"aws:ARN": "${ec2:SourceInstanceARN}"
}
}
}
]
}
Clearly for testing purposes I allowed my instances with this policy to tag and stop themselves.
Since the "aws:ARN" condition no longer works, I have found the following approach to work for instances launched with an IAM role:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Allow instance to modify itself",
"Effect": "Allow",
"Action": [
"ec2:DeleteTags",
"ec2:CreateTags"
],
"Resource": "*",
"Condition": {
"StringLike": {
"aws:userid": "*:${ec2:InstanceID}"
}
}
}
]
}

AWS IAM Policy to Grant All service permission to specific instances

I have setup separate IAM users from the root account with various privilege levels and I need provide all EC2 services access for 2 specific instances to a particular IAM user
I used AWS policy generator and got the below policy but it doesn't work
{
"Version": "2012-10-17",
"Statement": [
{
"Action": "ec2:*",
"Effect": "Allow",
"Resource": [
"arn:aws:ec2:us-east-1:ACCOUNT_ID:instance/INSTANCE_ID",
"arn:aws:ec2:us-east-1:ACCOUNT_ID:instance/INSTANCE_ID"
]
}
]
}
How can I grant permission to the specific instances so the IAM user can only manage those specific instances without accessing any other instances or services.
You can achieve this via Tags. As stated by the AWS Docs, you can try the below policy.
{
"Version": "2012-10-17",
"Statement": [
{
"Action": [
"ec2:StartInstances",
"ec2:StopInstances",
"ec2:RebootInstances"
],
"Condition": {
"StringEquals": {
"ec2:ResourceTag/Owner": "Bob"
}
},
"Resource": [
"arn:aws:ec2:us-east-1:111122223333:instance/*"
],
"Effect": "Allow"
},
{
"Effect": "Allow",
"Action": "ec2:Describe*",
"Resource": "*"
}
]
}

AWS S3 bucket policy notprincipal deny

My goal is to create exclusive access to a bucket for one IAM user, and to maintain that exclusivity easily as new iam users and groups are added. The user is outside of my control and has a managed policy attached to it:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "FullTestBucketS3Access",
"Action": "s3:*",
"Effect": "Allow",
"Resource": [
"arn:aws:s3:::test",
"arn:aws:s3:::test/*"
]
}
]
}
I have applied a bucket policy to the bucket that needs to exclude all users except one:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Deny",
"NotPrincipal": {
"AWS": [
"arn:aws:iam::111111111111:root",
"arn:aws:iam::111111111111:user/myuser"
]
},
"Action": [
"s3:DeleteObject"
],
"Resource": [
"arn:aws:s3:::test",
"arn:aws:s3:::test/*"
]
}
]
}
I am finding that the mask provided by the NotPrincipal part of the deny statement is not working. All users are denied the ability to take the action specified in the deny policy. What should I be looking at to work this out?