Uly.me

cloud engineer

aws

AWS Certificate List

Here’s how to get a list of certificates in AWS Certificate Manager.

aws acm list-certificates \
--profile default \
--region us-east-1 \
--output text \
--query 'CertificateSummaryList[*].{ARN:CertificateArn,Domain:DomainName}'

EC2 Password Authentication

When you stand up an AWS instance, it’s only accessible via SSH key using the default user, typically ec2-user.

Add password to ec2-user, then enable password authentication to ‘yes’ in SSH.

# Add password to ec2-user
sudo passwd ec2-user
# edit ssh config
vim /etc/ssh/sshd_config
# enable password authentication
PasswordAuthentication yes
# save file and exit

Restart SSH service.

systemctl restart sshd.service

AWS EC2 Describe Snapshots

Here’s how to describe snapshots using query with tags.

aws ec2 describe-snapshots \
--owner-ids xxxxxxxxxxx \
--profile default \
--region us-east-2 \
--output text \
--query "Snapshots[*].[SnapshotId,Tags[?Key=='Name'].Value[] | [0]]"

Result.

snap-xxxxxxxxxxxxxxxxx	Server1
snap-xxxxxxxxxxxxxxxxx	Server2

AWS S3 Sync Between Accounts

Here’s how to sync S3 buckets between 2 different AWS accounts. Assuming buckets are already created.

  1. Setup bucket permissions in Account A
  2. Setup IAM user with permissions in Account B
  3. Setup bucket permissions in Account B
  4. Run S3 sync from Account B.

Account A bucket permissions. Account and user are from Account B.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "DelegateS3Access",
            "Effect": "Allow",
            "Principal": {"AWS": "arn:aws:iam::222222222222:user/Jane"},
            "Action": ["s3:ListBucket","s3:GetObject"],
            "Resource": [
                "arn:aws:s3:::awsexamplesourcebucket/*",
                "arn:aws:s3:::awsexamplesourcebucket"
            ]
        }
    ]
}

Create IAM user (Jane) in Account B

aws iam create-user --user-name Jane

Give IAM user (Jane) access to both buckets.

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket",
                "s3:GetObject"
            ],
            "Resource": [
                "arn:aws:s3:::awsexamplesourcebucket",
                "arn:aws:s3:::awsexamplesourcebucket/*"
            ]
        },
        {
            "Effect": "Allow",
            "Action": [
                "s3:ListBucket",
                "s3:PutObject",
                "s3:PutObjectAcl"
            ],
            "Resource": [
                "arn:aws:s3:::awsexampledestinationbucket",
                "arn:aws:s3:::awsexampledestinationbucket/*"
            ]
        }
    ]
}

Sync the buckets

aws s3 sync s3://awsexamplesourcebucket s3://awsexampledestinationbucket

AWS CLI AutoScaler Update

Here’s the AWS CLI command to set the Auto Scaling Group to a certain number for the minimum, maximum, and desired number of instances.

#!/bin/bash
# Format:  
# ./autoscaling.sh 3
# ./autoscaling.sh 0
int=$1
aws autoscaling update-auto-scaling-group \
--auto-scaling-group-name your-auto-scaling-group \
--min-size $int \
--max-size $int \
--desired-capacity $int \
--region us-east-2

Format:

./autoscaling.sh 0
./autoscaling.sh 3

WAF CloudFormation Template

Here’s the CloudFormation template for creating a WAF.

Here are some options that you’ll be asked during creation.

  • Activate SQL Injection Protection ( yes | no )
  • Activate Cross-site Scripting Protection ( yes | no )
  • Activate HTTP Flood Protection ( WAF rate | Lambda log parser | Athena log parser | no )
  • Activate Scanner & Probe Protection ( Lambda log parser | Athena log parser | no )
  • Activate Reputation List Protection ( yes | no )
  • Activate Bad Bot Protection ( yes | no )
  • Endpoint Type (CloudFront or ALB)
  • Application Access Log Bucket Name ( Leave blank if no S3 bucket)

The template creates 2 CloudFormation stacks.