AWS S3 cp Command

Understanding the AWS S3 cp Command

AWS S3 (Simple Storage Service) is widely known for its scalability, data availability, security, and performance. One of the essential tools when working with S3 is the AWS Command Line Interface (CLI). The aws s3 cp command is a powerful utility for copying files to and from S3 buckets.

Installing AWS CLI

Before using aws s3 cp, you need the AWS CLI installed on your machine. The process is straightforward. Visit the AWS CLI official website and download the installation package suitable for your operating system. Follow the installation instructions provided on the site.

Configuring AWS CLI

After installation, configure the AWS CLI with your credentials. Run:

aws configure

You’ll be prompted for your AWS Access Key ID, Secret Access Key, Default Region Name, and Default Output Format. Ensure you have these credentials ready.

Basic Syntax of aws s3 cp

The aws s3 cp command has a basic syntax:

aws s3 cp [source] [destination] [options]

The source is where you’re copying from, and the destination is where you’re copying to. Different options modify the behavior of the command.

Copying a Single File to S3

To copy a single file to an S3 bucket, use the following syntax:

aws s3 cp file.txt s3://my-bucket/

Here, file.txt is the file on your local system, and s3://my-bucket/ is the destination bucket in S3.

Copying a File from S3

Copying a file from an S3 bucket to your local system is just as easy:

aws s3 cp s3://my-bucket/file.txt ./file.txt

This command copies file.txt from the S3 bucket my-bucket to your current local directory.

Copying Files Recursively

Using the --recursive option, you can copy all files within a directory to an S3 bucket. For example:

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

This command copies the entire contents of my-directory to the my-bucket.

Preserving Metadata

Sometimes, you might want to preserve the metadata of the copied files. Use the --metadata flag to specify metadata in the form of key-value pairs:

aws s3 cp file.txt s3://my-bucket/ --metadata key1=value1,key2=value2

This command adds custom metadata to file.txt in the S3 bucket.

Setting ACLs

You can also set Access Control Lists (ACLs) during file copy operations. The --acl option allows you to specify different permissions. For instance:

aws s3 cp file.txt s3://my-bucket/ --acl public-read

This command sets the file accessibility to public-read.

Using Storage Classes

S3 offers various storage classes, and you can specify the desired storage class during the copy operation using the --storage-class option. For example:

aws s3 cp file.txt s3://my-bucket/ --storage-class STANDARD_IA

This command copies file.txt to the STANDARD_IA (Infrequent Access) storage class.

Dry Run Option

If unsure of the results of a command, use --dryrun to preview without actual execution:

aws s3 cp my-directory s3://my-bucket/ --recursive --dryrun

This command simulates copying files without making any changes.

Including and Excluding Files

To be more specific about the files you want to include or exclude, use the --include and --exclude options. For example:

aws s3 cp my-directory s3://my-bucket/ --recursive --exclude *.tmp --include *.txt

This command copies all text files to the bucket, excluding temporary files.

Multipart Upload for Large Files

For substantial file sizes, AWS S3 automatically handles multipart uploads. This feature is especially useful for large files:

aws s3 cp largefile.iso s3://my-bucket/ --storage-class ONEZONE_IA

This command uploads in multiple parts, ensuring efficient transfer.

Transferring Data Between Buckets

You can also copy files directly between buckets:

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

This is handy when migrating data between environments.

Managing Versioned Buckets

When working with versioned buckets, specify the version ID during copy operations:

aws s3 cp s3://my-bucket/file.txt s3://my-other-bucket/ --version-id MY_VERSION_ID

This command copies a specific version of the file.

Using Regular Expressions

Regex can refine include and exclude patterns:

aws s3 cp my-dir s3://my-bucket/ --recursive --exclude * --include log[0-9].txt

This command includes specific log files while excluding others.

Enabling Server-Side Encryption

Add server-side encryption using the --sse option:

aws s3 cp file.txt s3://my-bucket/ --sse AES256

This ensures the file is encrypted server-side with AES256.

Setting Cache Control Headers

Customize cache control headers with the --cache-control option:

aws s3 cp file.txt s3://my-bucket/ --cache-control max-age=3600

This command sets a 1-hour cache duration.

Using Custom User Agent

Set a custom user agent for the requests using the --user-agent flag:

aws s3 cp file.txt s3://my-bucket/ --user-agent my-app

Beneficial for uniquely identifying requests.

Cross-Region Copies

Copy data between different AWS regions using the --source-region and --region flags:

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

Ensures correct interaction across regions.

Advanced Progress and Debugging

For enhanced progress tracking, use the --progress flag:

aws s3 cp file.txt s3://my-bucket/ --progress

This provides detailed progress feedback during transfers. For debugging, use --debug:

aws s3 cp file.txt s3://my-bucket/ --debug

Displays detailed debugging information.

Overwriting and Preserving Files

Control overwriting of existing files using --no-clobber:

aws s3 cp file.txt s3://my-bucket/ --no-clobber

Prevents existing files from being overwritten.

Error Handling and Retries

Configure retry behavior with the --max-concurrent-requests and --max-bandwidth options:

aws s3 cp my-directory s3://my-bucket/ --max-concurrent-requests 10 --max-bandwidth 50MB

Optimizes performance and error recovery.

Conclusion

The aws s3 cp command is versatile and powerful, providing numerous options for handling file transfers to and from AWS S3. By mastering this command, you can streamline your workflow and effectively manage your cloud storage.