AWS - Custom AMI

CUSTOM AMI

Disaster recovery is not an option. It's a necessity.

Q : What is custom AMI ? and Why is it needed ?

To start with, let's define what an AMI is. AMI stands for Amazon Machine Image, which is essentially a pre-configured virtual machine image that you can use to quickly launch instances in the AWS cloud. AMIs are available for a variety of operating systems, including Linux, Windows, and Red Hat, as well as for other software products such as Palo Alto Networks firewalls (from Amazon Marketplace ). By using an AMI, you can easily launch instances with your desired configuration, without having to manually install and configure each component from scratch.

A custom AMI is a tailored version of an existing AMI that has been modified to include custom software, security configurations, and other desired settings. In other words, it's a snapshot of a specific instance that has been modified to meet a particular set of requirements.

So why is a custom AMI important? Well, let's say you have an Amazon Linux EC2 instance that has been configured with specific networking tools. If a new employee joins your team and needs access to the same instance, launching a new EC2 instance and manually configuring it with the same set of tools can be a time-consuming and error-prone process. By creating a custom AMI of the already-configured instance, you can quickly and easily launch new instances with the exact same software and configuration settings.

So, let's dive a bit deeper into custom AMIs. One of the key benefits of using a custom AMI is that it allows you to standardize your infrastructure across multiple instances. This can be especially useful in larger organizations where you may have multiple teams launching instances for different purposes. By using a custom AMI, you can ensure that each instance has the same software stack, security configuration, and other settings. This can help to reduce errors and ensure that all instances are consistent.

Another benefit of using a custom AMI is that it allows you to perform advanced customization of your instances. For example, you can use a custom AMI to modify the kernel or other low-level components of your instance. This can be useful in scenarios where you need to optimize the performance of your instances or add custom functionality.

It's also worth noting that custom AMIs can be shared across accounts, regions, and even with other AWS users. This can be useful in scenarios where you need to collaborate with other teams or share infrastructure across different parts of your organization.

In terms of technical jargon, there are a few key concepts that are worth mentioning. For example, when you create a custom AMI, you are essentially creating a new Amazon EBS-backed AMI from an existing instance. This involves creating a new Amazon EBS snapshot of the instance's root volume and then registering the snapshot as a new AMI. You can then use this custom AMI to launch new instances with the same software stack and configuration.

Q: How to launch Custom AMI ?

• Launch an EC2 instance to use as the basis for the AMI.
• Customize the instance by installing software and making configuration changes.
• Stop the instance to ensure data consistency when creating a snapshot.
• Create a snapshot of the instance's root volume. **
• Create an AMI based on the snapshot, specifying the name and description.
• Launch instances from the AMI with the same configuration as the original instance.

** When creating an AMI, you can create a snapshot of either an EBS volume or an instance store volume ( ephemeral volume ), depending on your use case. However, it's important to note that when creating an AMI, you typically only need to create a snapshot of the root volume, which is where the operating system and other critical components are stored.

EBS volumes are network-attached volumes that can be created and attached to EC2 instances in a specific Availability Zone. They persist independently of the life of an instance, and can be backed up using snapshots. However , ephemeral volumes that are physically attached to the host computer, These volumes can provide higher I/O performance, but data on these volumes will be lost if the instance is stopped or terminated.

Q: How can we ensure reliability or DR Situation using AMI ?

AMI can help improve reliability and disaster recovery (DR) situations in several ways:

1. Quick Recovery: By creating an AMI of a fully configured and tested EC2 instance, you can easily and quickly launch identical instances in case of an instance failure or other DR event, which can significantly reduce recovery time.
2. Consistency: An AMI provides consistency in the configuration of the launched instances, which ensures that the instances are always built using the same software and configuration as the original instance.
3. Replication: AMIs can be replicated across different regions, ensuring that they are available in multiple locations. This helps to improve availability and reduce the impact of outages in a specific region.
4. Versioning: AMIs can be versioned, allowing you to track and manage different versions of your instances. This helps to ensure that you can roll back to a known good state if a new version causes problems.
5. Testing: You can use AMIs to test your applications in an environment that is identical to the production environment, which can help to catch issues early and improve the overall reliability of your applications.

** It's important to note that when creating an AMI, the root volume data will be included in the snapshot, but data from the ephemeral disk will not be included in the snapshot. This means that any data stored on the ephemeral disk will be lost when creating an AMI, so it's important to ensure that any critical data is stored on an EBS volume or backed up separately.

Q : How can we ensure security in custom AMI ?

1. Patch Management: It's important to ensure that the operating system and any software installed on the AMI are regularly patched and updated to address any security vulnerabilities.
2. Minimize Access: You should minimize the access to the AMI, limiting access to only those who require it. Use AWS Identity and Access Management (IAM) to control access to the AMI.
3. Hardening: Hardening the AMI involves securing the operating system and application settings, disabling unnecessary services and ports , and ensuring that the system is configured to meet security best practices.
4. Encryption: Encrypting sensitive data at rest can add an extra layer of security to your AMI. Use AWS Key Management Service (KMS) or third-party encryption tools to encrypt data stored in the AMI.
5. Regular Auditing: It's important to regularly audit the AMI to ensure that it meets the organization's security requirements. This can include performing vulnerability scans and penetration testing. and AWS Security Hub to ensure that your custom AMI is secure and meets your organization's security requirements.

Q: In what scenarios can using AMI be the best choice for a well-architected framework?

Using AMI can be an excellent choice for well-architected frameworks in several scenarios. One common scenario is when deploying identical or similar application stacks across different environments, such as development, staging, and production environments. By creating a custom AMI, you can ensure that each environment has the same application stack and configuration, making it easier to manage and reducing the risk of errors caused by differences between environments.

AMI can also be a best choice in disaster recovery scenarios, where you need to quickly launch identical instances in a separate availability zone or region. By creating a custom AMI of your production environment, you can minimize downtime and ensure business continuity in case of a disaster or failure.

Moreover, if you're working with auto-scaling groups or frequently launching instances, using a custom AMI can ensure that all instances have the same configuration and are built on a known-good configuration, minimizing risk and ensuring consistency.

Overall, using AMI can be an excellent choice for a well-architected framework in various scenarios, providing consistent and reliable deployments and minimizing risk in the event of a failure or disaster.

Q : What? are Alternate solutions for AMI ?

1. Bootstrapping: Instead of creating a custom AMI, you can use bootstrapping to automate the installation and configuration of software and dependencies on instances at launch time. You can use tools like AWS CloudFormation, AWS OpsWorks, or user data scripts to automate the bootstrapping process and ensure consistency across instances.
2. Docker: Another alternative is to use containerization with Docker to package and deploy applications. Docker images can be created with the necessary software and dependencies, and then deployed to instances using Amazon Elastic Container Service (ECS) or Elastic Kubernetes Service (EKS).
3. Lambda Functions: For serverless applications or functions, AWS Lambda provides a platform for running code without provisioning or managing servers. Lambda functions can be used to execute application logic in response to events or triggers, without the need for a dedicated instance or custom AMI.
4. Configuration Files: Finally, you can use configuration files to manage the software and dependencies on instances. Configuration management tools like Chef, Puppet, or Ansible can be used to automate the installation and configuration of software and dependencies, and ensure consistency across instances.

5. Infrastructure as code: Infrastructure as code (IaC) allows you to define and manage your infrastructure using code. Tools like AWS CloudFormation, Terraform, or Pulumi can be used to create, update, and delete your resources in a declarative and repeatable way.

Q: What automated methods can be used to create snapshots of a custom AMI when changes are made to the image, given that the previous snapshot will become outdated and unusable?

As a best practice, AWS recommends using Amazon EBS-backed AMIs, which provide the ability to create snapshots of the EBS volumes. To ensure that your custom AMI is up-to-date and secure, you can automate the process of creating snapshots by using Amazon Data Lifecycle Manager (DLM) or AWS Backup. These services allow you to schedule automatic snapshots of your EBS volumes on a regular basis, ensuring that your AMI is always up-to-date and can be easily restored in the event of an unexpected failure.

Or? to automate the process of creating new snapshots through tools like AWS Lambda, AWS CloudFormation, or third-party solutions like HashiCorp Packer. These tools can help to automatically create and update snapshots or perform incremental backups, allowing for efficient and reliable AMI management.

Q: What are the cost aspects related to Snapshot and AMI ?

When it comes to the cost aspects related to snapshots and AMIs, there are several factors to consider. First, both snapshots and AMIs incur charges for storage, based on the size and duration of the data being stored. In addition, there may be costs associated with data transfer, if you need to move the snapshot or AMI across regions or to other AWS services.

To help manage these costs, AWS provides various options for lifecycle management of snapshots and AMIs. For example, you can use Amazon S3 Lifecycle policies to automatically transition snapshots to lower-cost storage classes as they age, or to expire them after a certain period of time. Similarly, you can use AWS Backup to schedule and manage backups of your EC2 instances and EBS volumes, with options for retention periods, deletion rules, and cross-region replication. It is recommended to use AWS Cost Explorer to monitor and analyze costs associated with these services.

Q : What are best practices for AMI ?

Best practices for AMI include:

1. Use automation tools such as AWS Systems Manager, AWS CloudFormation, or AWS OpsWorks to streamline the AMI creation process.
2. Implement a tagging strategy for your AMIs to help with organization and tracking.
3. Regularly update your AMIs to ensure that they contain the latest software patches and security updates.
4. Delete unused AMIs to free up storage space and reduce costs.
5. Use AWS services that support snapshots to create and manage your AMIs, such as Amazon EBS (Elastic Block Store) and Amazon S3 (Simple Storage Service).
6. Use AWS CloudTrail to monitor and audit AMI creation and deletion activities.
7. Implement security best practices for your AMIs, such as encrypting sensitive data and using AWS Identity and Access Management (IAM) to control access to your AMIs.
8. Create AMIs in multiple regions to ensure availability and reduce latency.

AWS services that support snapshot and AMI management include:

1. Amazon Elastic Block Store (EBS) - used to create and manage block storage volumes for EC2 instances. EBS volumes can be used to store data and also to create snapshots of the volume, which can be used to create AMIs.
2. Amazon S3 (Simple Storage Service) - used to store and retrieve data. S3 can also be used to store AMIs, which can be copied across regions or shared with other AWS accounts.
3. AWS Backup - a fully-managed backup service that automates backup and recovery processes for AWS services, including EC2 instances, EBS volumes, and AMIs.
4. AWS Systems Manager - a unified interface used to manage resources across AWS services. Systems Manager can be used to create, manage, and share AMIs across AWS accounts.
5. AWS Marketplace - an online store for third-party software that runs on AWS. AWS Marketplace offers a wide selection of AMIs from various vendors, including pre-configured software stacks and operating systems.

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