How to Copy Files from Pods to Local Machine using kubectl cp?

Have you ever been involved in copying files from Kubernetes Pods to a local machine? Do you want to learn to use kubectl cp to copy files seamlessly between Pods and your local machine?

In Kubernetes, it is important for both DevOps engineers and developers to manage containers and the resources they use. Working with Kubernetes often involves copying files between Pods.

This is where kubectl cp comes into play—a powerful tool that enables users to copy files between Kubernetes Pods and their local machines.

This article will explain the kubectl cp command in-depth, including its syntax and usage. We will also provide practical examples to demonstrate how to copy files between Kubernetes Pods and your local machine using it.

Let’s get started.

Key Takeaways

• kubectl cp is a command that copies files and directories between your local machine and Kubernetes Pods.
• kubectl cp is a command, and you can use it for various real-world scenarios, including debugging, backup and restore, data migration, and building and deploying applications. Using kubectl cp, you can simplify many everyday Kubernetes tasks and save time and effort.

What is kubectl cp?

kubectl cp is a command that is used to manage Kubernetes clusters. It is used for various everyday tasks such as creating and managing Pods, services, and deployments, scaling resources up or down, and deploying new applications.

When working with Kubernetes, developers and DevOps engineers often move files between their local machines and the Kubernetes Pods.

kubectl cp is a command that extends the functionality of the kubectl tool, allowing users to copy files to and from Kubernetes Pods using a simple command line interface. It provides a straightforward and efficient way of managing file transfers, eliminating the need for complex scripts or manual transfers.

Also Read: The Ultimate Guide to the Best Kubernetes Certifications in 2023

The Syntax of kubectl cp

kubectl cp is similar to the standard Linux cp command and is used to copy files between a local machine and a Kubernetes cluster or between containers in the same cluster.

You can use the following command to copy a file from the local machine to a Pod in the Kubernetes cluster:

kubectl cp /<path-to-your-file>/<file-name> <pod-name>:<fully-qualified-file-name> -c <container-name>

To copy a file from a Pod in the Kubernetes cluster to the local machine, you can use the following command:

kubectl cp <pod-name>:<fully-qualified-file-name> /<path-to-your-file>/<file-name> -c <container-name>

In both commands, <pod-name> refers to the name of the Pod that you want to copy the file to or from, <fully-qualified-file-name> refers to the full path of the file within the container, and <container-name> refers to the name of the container within the Pod.

Copy File From Local Machine to Pod

To copy a file from your local machine to a container, you can use the following command: :

kubectl cp /<path-to-your-file>/<file-name> <pod-name>:<folder>/<file-name> -c <container-name>

If a Pod contains multiple containers, you must specify the container you are copying files to/from when using the kubectl cp command.

A Pod’s containers can be listed using the following command:

➜ kubectl get pods <pod-name> -o jsonpath='{.spec.containers[*].name}'

Here are some examples to help you better understand.

➜ kubectl cp /Users/vishn/Desktop/index.html tomcatinfra-7f58bf9cb8-wvmhl:ROOT/index.html -c tomcat8 ➜ kubectl cp /Users/vishn/Desktop/gritfygif.gif tomcatinfra-7f58bf9cb8-wvmhl:ROOT/gritfygif.gif -c tomcat8

In this example, we chose the container where our web server is installed, added a GIF file to the index.html page, and made a new default landing page to replace the old one.

Copy File From a Pod to a Local Machine

You can use the following command to copy a file from your Pod to your local machine:

kubectl cp name-of-your-pod:/path/to/your_folder /path/on_your_host/to/your_folder

Here we will copy the error log file from my-lamp-server to the local machine:

kubectl cp my-lamp-server:/var/log/apache2/error.log /home/sammy/error.log

Example Use Cases

A kubectl cp command can be used for various real-world scenarios. Here are some examples of how kubectl cp can be used:

• Debugging: kubectl cp can download logs and configuration files from a Pod. Using this information can be helpful when troubleshooting production issues.
• Backup and restore: kubectl cp can create backups of important files and configurations stored in a Pod and restore them in case of data loss or system failures.
• Data migration:kubectl cp can transfer data between Pods in a Kubernetes cluster or between clusters.
• Building and deploying applications: kubectl cp can copy application binaries and configuration files from a local machine to a Pod, simplifying the process of building and deploying applications.

In addition to copying files, kubectl cp can copy directories and their contents. To copy a directory from your local machine to a Kubernetes Pod, you can follow these steps:

kubectl cp /path/to/local/directory <pod-name>:/path/to/destination

And here is an example of how to copy a directory from a Kubernetes Pod to your local machine:

kubectl cp <pod-name>:/path/to/directory /path/to/destination

Using kubectl cp to copy directories, you can easily transfer large amounts of data between your local machine and Kubernetes Pods without manually transferring each individual file.

FAQs

How do I copy files within the same Pod using kubectl cp from one container to another?

To copy files between containers within the same Pod, you can use the -c flag followed by the container name in the kubectl cp command.

For example,

kubectl cp <pod-name>:/path/to/file.txt /path/to/destination -c <container-name>

Can I use kubectl cp to copy files between Kubernetes clusters?

You can use kubectl cp to copy files between different Kubernetes clusters by specifying the appropriate context for the source and destination clusters.

For example,

kubectl --context=source-context cp <source> --context=destination-context:<destination> [flags]

How can I verify that a file has been successfully copied using kubectl cp?

You can verify that a file has been successfully copied using kubectl cp by checking the content of the destination file or directory. You can also use the diff command to compare the source and destination files to ensure they are identical.

For example,

diff /path/to/source/file.txt /path/to/destination/file.txt

Conclusion

kubectl cp is a command for developers and DevOps engineers who often move files between Kubernetes Pods and their local machines. The command allows for easy file transfers, eliminating the need for complex scripts or manual transfers. With its simple syntax and versatility, kubectl cp can be used for various real-world scenarios, including backup and restore, data migration, building and deploying applications, and debugging.

Following the examples in this article, readers can quickly learn how to use kubectl cp to make common Kubernetes tasks easier and save time and effort. With kubectl cp, losing valuable data due to file transfers is now a thing of the past.

I hope this article will help you to understand how to copy files from Pods to a local machine and vice-versa using the kubectl cp command-line utility. Share it with your peers if you feel worth sharing it.

Also Read: Kairos: Empowering On-Premises Environments with Cloud-Native Meta-Linux Distribution