AWS Command Line Interface Interview Questions and Answers

The AWS Command Line Interface (CLI) is a powerful tool that allows you to control AWS services from the command line.

1. What is the AWS CLI?

The AWS Command Line Interface (CLI) is a unified tool to manage your AWS services. With the AWS CLI, you can control multiple AWS services from the command line and automate them through scripts. The AWS CLI is available for Windows, macOS, and Linux.

To use the AWS CLI, you need to install it on your local machine and then configure it with your AWS access keys, which you can obtain from the AWS Management Console. Once you have the AWS CLI installed and configured, you can use it to perform various operations on AWS services, such as creating and managing Amazon Elastic Compute Cloud (Amazon EC2) instances, storing and retrieving data in Amazon Simple Storage Service (Amazon S3), and managing Amazon Virtual Private Cloud (Amazon VPC) resources.

The AWS CLI includes a large number of command-line options and subcommands that allow you to control nearly every aspect of your AWS resources. For example, you can use the AWS CLI to create and delete Amazon S3 buckets, upload and download objects to and from Amazon S3, and list the objects in a bucket. You can also use the AWS CLI to create and manage Amazon EC2 instances, view and modify Amazon VPC resources, and view and modify the security groups associated with your Amazon EC2 instances.

Overall, the AWS CLI is a powerful tool that can help you automate your AWS workloads and manage your AWS resources more efficiently.

2. Can you explain what a command line interface (CLI) tool is?

The AWS Command Line Interface (CLI) is a unified tool that allows you to control multiple AWS services from the command line. It is a powerful tool that can help you automate your AWS workloads and manage your AWS resources more efficiently.

To use the AWS CLI, you need to install it on your local machine and then configure it with your AWS access keys, which you can obtain from the AWS Management Console. Once you have the AWS CLI installed and configured, you can use it to perform various operations on AWS services, such as creating and managing Amazon Elastic Compute Cloud (Amazon EC2) instances, storing and retrieving data in Amazon Simple Storage Service (Amazon S3), and managing Amazon Virtual Private Cloud (Amazon VPC) resources.

The AWS CLI includes a large number of command-line options and subcommands that allow you to control nearly every aspect of your AWS resources. For example, you can use the AWS CLI to create and delete Amazon S3 buckets, upload and download objects to and from Amazon S3, and list the objects in a bucket. You can also use the AWS CLI to create and manage Amazon EC2 instances, view and modify Amazon VPC resources, and view and modify the security groups associated with your Amazon EC2 instances.

Overall, the AWS CLI is a useful tool for managing your AWS resources and automating your AWS workloads. It is available for Windows, macOS, and Linux, and can be used in scripts and on the command line.

3. How do you install and configure AWS CLI on Linux, Windows, macOS, or Unix-based operating systems?

To install and configure the AWS Command Line Interface (CLI) on Linux, Windows, macOS, or Unix-based operating systems, you can follow these steps:

1. Install the AWS CLI:

On Linux:

• Download the AWS CLI MSI installer for Windows from this link: https://awscli.amazonaws.com/AWSCLIV2.msi
• Run the MSI installer and follow the prompts to install the AWS CLI.

On Windows:

• Download the AWS CLI MSI installer for Windows from this link: https://awscli.amazonaws.com/AWSCLIV2.msi
• Run the MSI installer and follow the prompts to install the AWS CLI.

On macOS

pip install awscli --upgrade --user

On Unix-based systems:

• Download the AWS CLI tar file from this link: https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip
• Extract the tar file and run the following command to install the AWS CLI:

./aws/install

2. Configure the AWS CLI:

Once you have the AWS CLI installed, you need to configure it with your AWS access keys. To do this, run the following command:

aws configure

This will prompt you to enter your AWS access key and secret access key, as well as your default region and output format. You can obtain your AWS access keys from the AWS Management Console.

Once you have entered your AWS access keys and chosen your default region and output format, the AWS CLI will be configured and ready to use.

You can also specify the access keys and default region as command-line options when running the aws configure command, as shown in the following example:

aws configure --access-key-id YOUR_ACCESS_KEY_ID --secret-access-key YOUR_SECRET_ACCESS_KEY --region YOUR_DEFAULT_REGION

You can use the AWS CLI to perform various operations on AWS services, such as creating and managing Amazon EC2 instances, storing and retrieving data in Amazon S3, and managing Amazon VPC resources.

4. Can you provide examples of some common uses for the AWS Command Line Interface?

Yes, here are some examples of common uses for the AWS Command Line Interface (CLI):

1. Managing Amazon Elastic Compute Cloud (Amazon EC2) instances:

• List all of your Amazon EC2 instances:

aws ec2 describe-instances

• Start an Amazon EC2 instance:

aws ec2 start-instances --instance-ids i-12345678

• Stop an Amazon EC2 instance:

aws ec2 stop-instances --instance-ids i-12345678

• Terminate an Amazon EC2 instance:

aws ec2 terminate-instances --instance-ids i-12345678

2. Storing and retrieving data in Amazon Simple Storage Service (Amazon S3):

• Create an Amazon S3 bucket:

aws s3 mb s3://my-bucket

• List the objects in an Amazon S3 bucket:

aws s3 ls s3://my-bucket

• Upload an object to an Amazon S3 bucket:

aws s3 cp /path/to/local/file s3://my-bucket/path/to/remote/file

• Download an object from an Amazon S3 bucket:

aws s3 cp s3://my-bucket/path/to/remote/file /path/to/local/file

3. Managing Amazon Virtual Private Cloud (Amazon VPC) resources:

• Create a new Amazon VPC:

aws ec2 create-vpc --cidr-block 10.0.0.0/16

• List your Amazon VPCs:

aws ec2 describe-vpcs

• Create a new Amazon VPC security group:

aws ec2 create-security-group --group-name my-security-group --description "My security group" --vpc-id vpc-12345678

• List your Amazon VPC security groups:

aws ec2 describe-security-groups

These are just a few examples of the many operations that you can perform using the AWS CLI. You can use the AWS CLI to manage nearly every aspect of your AWS resources, including Amazon EC2 instances, Amazon S3, Amazon VPC, and many other services.

5. How would you use the AWS CLI to create an Amazon S3 bucket?

To create an Amazon S3 bucket using the AWS Command Line Interface (CLI), you can use the aws s3 mb command, followed by the name of the bucket that you want to create.

Here is an example of how to create an Amazon S3 bucket using the AWS CLI:

aws s3 mb s3://my-new-bucket

This command will create an Amazon S3 bucket with the name “my-new-bucket” in the default region.

If you want to specify a different region for the bucket, you can use the --region option, as shown in the following example:

aws s3 mb s3://my-new-bucket --region us-west-2

This command will create an Amazon S3 bucket with the name “my-new-bucket” in the US West (Oregon) region.

You can also specify additional options when creating an Amazon S3 bucket, such as the bucket’s access control list (ACL) and the storage class. For example:

aws s3 mb s3://my-new-bucket --acl public-read --storage-class REDUCED_REDUNDANCY

This command will create an Amazon S3 bucket with the name “my-new-bucket” in the default region, with a public-read ACL and the REDUCED_REDUNDANCY storage class.

Overall, the AWS CLI provides a convenient way to create and manage Amazon S3 buckets and objects from the command line. You can use the AWS CLI to perform a wide range of operations on Amazon S3, including uploading and downloading objects, listing objects in a bucket, and deleting buckets and objects.

6. How can you use the AWS CLI to list all instances in your account with their instance ID, instance type, and private IP address?

To list all instances in your AWS account with their instance ID, instance type, and private IP address using the AWS Command Line Interface (CLI), you can use the aws ec2 describe-instances command with the --query option to specify the information that you want to retrieve.

Here is an example of how to list all instances in your AWS account with their instance ID, instance type, and private IP address:

aws ec2 describe-instances --query 'Reservations[*].Instances[*].[InstanceId,InstanceType,PrivateIpAddress]'

This command will retrieve the instance ID, instance type, and private IP address for all instances in your AWS account and display them in a list.

You can also use the --output option to specify the format in which the output is displayed. For example, to display the output in a table format, you can use the following command:

aws ec2 describe-instances --query 'Reservations[*].Instances[*].[InstanceId,InstanceType,PrivateIpAddress]' --output table

Overall, the AWS CLI provides a convenient way to list and manage your Amazon Elastic Compute Cloud (Amazon EC2) instances from the command line. You can use the AWS CLI to perform a wide range of operations on Amazon EC2, including creating and deleting instances, starting and stopping instances, and modifying instance settings.

7. How can you use the AWS CLI to get information about a specific EBS volume?

To get information about a specific Amazon Elastic Block Store (Amazon EBS) volume using the AWS Command Line Interface (CLI), you can use the aws ec2 describe-volumes command with the --volume-ids option to specify the ID of the volume that you want to retrieve information about.

Here is an example of how to get information about an Amazon EBS volume using the AWS CLI:

aws ec2 describe-volumes --volume-ids vol-12345678

This command will retrieve information about the Amazon EBS volume with the ID “vol-12345678”, including the volume ID, size, type, and availability zone.

You can also use the --query option to specify the specific information that you want to retrieve. For example, to retrieve only the volume ID and size, you can use the following command:

aws ec2 describe-volumes --volume-ids vol-12345678 --query 'Volumes[*].[VolumeId,Size]'

You can also use the --output option to specify the format in which the output is displayed. For example, to display the output in a table format, you can use the following command:

aws ec2 describe-volumes --volume-ids vol-12345678 --query 'Volumes[*].[VolumeId,Size]' --output table

Overall, the AWS CLI provides a convenient way to get information about Amazon EBS volumes and perform various operations on them from the command line. You can use the AWS CLI to create and delete Amazon EBS volumes, attach and detach volumes from instances, and modify volume settings.

8. Using the AWS CLI, how would you download the most recent backup file from an Amazon S3 Bucket?

To download the most recent backup file from an Amazon Simple Storage Service (Amazon S3) bucket using the AWS Command Line Interface (CLI), you can use the aws s3 cp command with the --recursive option to download all objects in the bucket, and then use the ls command to list the objects and find the most recent ones.

Here is an example of how to download the most recent backup file from an Amazon S3 bucket using the AWS CLI:

1. Navigate to the local directory where you want to download the backup file:

cd /path/to/local/directory

2. Download all objects in the Amazon S3 bucket to the local directory:

aws s3 cp s3://my-bucket . --recursive

3. List the objects in the local directory and find the most recent one:

ls -ltr

This command will list the objects in the local directory in order of their modification time, with the most recent ones at the end of the list. You can then identify the most recent backup file and use it as needed.

You can also use the --exclude and --include options to specify the objects that you want to download. For example, to download only objects with the “.bak” extension, you can use the following command:

aws s3 cp s3://my-bucket . --recursive --include "*.bak"

Overall, the AWS CLI provides a convenient way to download and manage objects in Amazon S3 from the command line. You can use the AWS CLI to perform a wide range of operations on Amazon S3, including uploading and downloading objects, listing objects in a bucket, and deleting buckets and objects.

9. How can you use the AWS CLI to send HTTP GET requests to an Elastic Load Balancer?

To send HTTP GET requests to an Amazon Elastic Load Balancer (Amazon ELB) using the AWS Command Line Interface (CLI), you can use the aws elbv2 describe-target-health command with the --target-group-arn option to specify the Amazon Resource Name (ARN) of the target group to that you want to send the request.

Here is an example of how to send an HTTP GET request to an Amazon ELB using the AWS CLI:

aws elbv2 describe-target-health --target-group-arn arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/my-target-group/1234567890abcdef

This command will send an HTTP GET request to the Amazon ELB and retrieve information about the health of the targets in the specified target group. The output will include the target ID, the health status of the target, and the reason for any unhealthy status.

You can also use the --output option to specify the format in which the output is displayed. For example, to display the output in a table format, you can use the following command:

aws elbv2 describe-target-health --target-group-arn arn:aws:elasticloadbalancing:us-east-1:123456789012:targetgroup/my-target-group/1234567890abcdef --output table

Overall, the AWS CLI provides a convenient way to send HTTP requests to an Amazon ELB and retrieve information about the health of the targets in the target group. You can use the AWS CLI to perform a wide range of operations on Amazon ELB, including creating and deleting load balancers, registering and deregistering targets, and modifying load balancer settings.

10. How can you use the AWS CLI to generate pre-signed URLs for objects stored in S3 buckets?

To generate pre-signed URLs for objects stored in Amazon Simple Storage Service (Amazon S3) buckets using the AWS Command Line Interface (CLI), you can use the aws s3 presign command with the --expires-in option to specify the number of seconds that the URL should be valid for.

Here is an example of how to generate a pre-signed URL for an object stored in an Amazon S3 bucket using the AWS CLI:

aws s3 presign s3://my-bucket/path/to/object --expires-in 3600

This command will generate a pre-signed URL for the object stored at “s3://my-bucket/path/to/object” that is valid for 3600 seconds (1 hour). You can then use this URL to access the object directly, without the need for AWS credentials.

You can also use the --method option to specify the HTTP method that the pre-signed URL should allow, such as GET, PUT, or DELETE. For example, to generate a pre-signed URL that allows GET and HEAD requests, you can use the following command:

aws s3

11. How would you set up AWS Multiple Profiles with different Credentials on your Workstation?

To set up multiple AWS profiles with different credentials on your workstation, you will need to edit the ~/.aws/credentials file in your home directory. This file stores the credentials for your AWS profiles, and you can use it to specify different profiles for different tasks or environments.

Here’s the general process for setting up multiple profiles:

1. Open the ~/.aws/credentials file in a text editor.
2. Add a new section to the file for each profile you want to create. The section should be in the following format:

[profile_name]
aws_access_key_id = YOUR_ACCESS_KEY_ID
aws_secret_access_key = YOUR_SECRET_ACCESS_KEY

Replace profile_name with the name, you want to use for the profile, and replace YOUR_ACCESS_KEY_ID and YOUR_SECRET_ACCESS_KEY with the access key ID and secret access key for the profile.

3. Save the file and exit the text editor.

Once you have set up your profiles in the ~/.aws/credentials file, you can use the AWS_PROFILE environment variable to specify which profile to use when running AWS CLI commands. For example, you could use the following command to run an AWS CLI command using the profile_name profile:

AWS_PROFILE=profile_name aws s3 ls

Alternatively, you can specify the profile using the --profile option when running AWS CLI commands:

aws s3 ls --profile profile_name

You can also set the AWS_DEFAULT_PROFILE environment variable to specify the default profile to use if no profile is specified.

I hope this helps! Let me know if you have any questions or need further assistance.

12. Is it possible to copy files between two S3 buckets using the AWS CLI? If yes, then how?

Yes, it is possible to copy files between two S3 buckets using the AWS CLI. You can use the aws s3 cp command to copy files from one bucket to another. The aws s3 cp the command has the following syntax:

aws s3 cp SOURCE_PATH DESTINATION_PATH

SOURCE_PATH is the path to the file or directory you want to copy, and DESTINATION_PATH is the path to the destination location.

Here’s an example of how you can use the aws s3 cp command to copy a file from one S3 bucket to another:

aws s3 cp s3://source-bucket/path/to/file.txt s3://destination-bucket/path/to/file.txt

This command will copy the file file.txt from the source-bucket bucket to the destination-bucket bucket.

You can also use the --recursive option to copy all the files in a directory and its subdirectories:

aws s3 cp s3://source-bucket/path/to/directory s3://destination-bucket/path/to/directory --recursive

This command will copy all the files and directories in the directory directory from the source-bucket bucket to the destination-bucket bucket.

13. What are some best practices when working with the AWS CLI?

Here are some best practices to follow when working with the AWS CLI:

1. Use profiles to store multiple sets of AWS credentials: You can use the ~/.aws/credentials file to store multiple sets of AWS credentials, which can be useful if you need to switch between different AWS accounts or access keys.
2. Use the --profile option to specify which profile to use: When running AWS CLI commands, you can use the --profile option to specify which profile to use. This is especially useful if you have multiple profiles set up in your ~/.aws/credentials file.
3. Use the --output option to specify the output format: The --output option allows you to specify the format of the command output. For example, you can use --output json it to output the command results in JSON format.
4. Use the --debug option to troubleshoot issues: The --debug the option can be useful for troubleshooting issues with AWS CLI commands. It will print additional debugging information to the console, which can help you identify the cause of any problems.
5. Use the --dry-run option to test commands before running them: The --dry-run option allows you to test an AWS CLI command without actually running it. This can be useful for testing the command syntax or for previewing the effects of the command.
6. Use the --region option to specify the region: If you are working with resources in a specific AWS region, you can use the --region option to specify the region. This can be helpful if you have multiple profiles set up, as it ensures that the command is run in the correct region.
7. Use the --query option to filter the output: The --query option allows you to filter the output of an AWS CLI command using JMESPath queries. This can be useful for extracting specific data from the command output.

14. How can you use the AWS CLI to get details about security groups associated with an EC2 Instance?

You can use the aws ec2 describe-security-groups command to get details about security groups associated with an EC2 instance. This command returns a list of security groups and their descriptions.

To get details about security groups associated with an EC2 instance, you will need to pass the --filters option to the aws ec2 describe-security-groups command. You can use the --filters option to specify a filter that selects the security groups associated with the EC2 instance.

Here’s an example of how you can use the aws ec2 describe-security-groups command to get details about security groups associated with an EC2 instance:

aws ec2 describe-security-groups --filters Name=vpc-id,Values=VPC_ID Name=instance-id,Values=INSTANCE_ID

Replace VPC_ID with the ID of the VPC that the EC2 instance belongs to, and replace INSTANCE_ID with the ID of the EC2 instance.

The command output will include a list of security groups and their descriptions, as well as other details such as the security group name, ID, and rules.

15. How can you use the AWS CLI to find out the status of any running instances?

You can use the aws ec2 describe-instances command to find out the status of running instances. This command returns a list of EC2 instances and their details, including the instance state.

To find out the status of running instances, you will need to pass the --filters option to the aws ec2 describe-instances command. You can use the --filters option to specify a filter that selects the running instances.

Here’s an example of how you can use the aws ec2 describe-instances command to find out the status of running instances:

aws ec2 describe-instances --filters "Name=instance-state-name,Values=running"

This command will return a list of EC2 instances that are currently running. The output will include the instance ID, state, and other details such as the instance type and availability zone.

You can also use the --query option to filter the output and extract specific information about the running instances. For example, the following command will return a list of the instance IDs of all the running instances:

aws ec2 describe-instances --filters "Name=instance-state-name,Values=running" --query "Reservations[*].Instances[*].InstanceId"

16. How would you use the AWS CLI to determine if there are any changes pending on your RDS database?

You can use the aws rds describe-pending-maintenance-actions command to determine if there are any changes pending on your RDS database. This command returns a list of pending maintenance actions and their details, including the type of action and the scheduled start time.

To use the aws rds describe-pending-maintenance-actions command, you will need to specify the identifier of the RDS instance or cluster that you want to check for pending maintenance actions. You can use the --filters option to specify a filter that selects the RDS instance or cluster.

Here’s an example of how you can use the aws rds describe-pending-maintenance-actions command to determine if there are any changes pending on an RDS database:

aws rds describe-pending-maintenance-actions --filters "Name=db-instance-id,Values=DB_INSTANCE_ID"

Replace DB_INSTANCE_ID with the identifier of the RDS instance that you want to check for pending maintenance actions.

If there are no pending maintenance actions, the command output will be empty. If there are pending maintenance actions, the output will include a list of the pending actions and their details.

You can also use the --query option to filter the output and extract specific information about the pending maintenance actions. For example, the following command will return a list of the types of pending maintenance actions:

aws rds describe-pending-maintenance-actions --filters "Name=db-instance-id,Values=DB_INSTANCE_ID" --query "PendingMaintenanceActions[*].Action"

17. How would you use the AWS CLI to monitor various metrics such as CPU utilization, network traffic, etc. for your EC2 server?

You can use the aws cloudwatch get-metric-statistics command to retrieve various metrics for your EC2 server. This command allows you to retrieve metric data for a specified time period and display it in the desired format.

To retrieve metrics for your EC2 server, you will need to specify the namespace, metric name, dimensions, and period for the metric data you want to retrieve. You can also use the --start-time and --end-time options to specify the time period for the metric data.

Here’s an example of how you can use the aws cloudwatch get-metric-statistics command to retrieve the CPU utilization for an EC2 instance:

aws cloudwatch get-metric-statistics --namespace AWS/EC2 --metric-name CPUUtilization --dimensions Name=InstanceId,Value=INSTANCE_ID --start-time START_TIME --end-time END_TIME --period 60 --statistics Average

Replace INSTANCE_ID the ID of the EC2 instance, START_TIME with the start time for the metric data (in ISO 8601 format), and END_TIME with the end time for the metric data (in ISO 8601 format). The --period option specifies the time interval, in seconds, for the returned data points. The --statistics option specifies the statistical function to apply to the data points.

You can also use the --output option to specify the output format for the command. For example, you can use --output json it to output the command results in JSON format.

18. Using the AWS CLI, how would you delete a specific object from an Amazon S3 Bucket?

You can use the aws s3 rm command to delete a specific object from an Amazon S3 bucket. The aws s3 rm command has the following syntax:

aws s3 rm S3_URL

S3_URL is the URL of the object you want to delete.

Here’s an example of how you can use the aws s3 rm command to delete an object from an S3 bucket:

aws s3 rm s3://bucket-name/path/to/object.txt

This command will delete the object object.txt from the bucket-name bucket.

You can also use the --recursive option to delete all the objects in a directory and its subdirectories:

aws s3 rm s3://bucket-name/path/to/directory --recursive

This command will delete all the objects and directories in the directory directory from the bucket-name bucket.