Kubernetes resources are the building blocks of Kubernetes objects. They're essential for all the basic pieces you need to build a container or pod things as CPU, memory, and disk space. Managing Kubernetes resources is essential because it allows you to control how much of each resource your application needs at any given time. You can also use this information to set quotas on how much each application can consume. For example, if you have an app that makes a lot of HTTP requests, you might want to limit its available memory, so it doesn't eat up all your RAM and crash your entire cluster!
What are Kubernetes Resources?
Kubernetes resources are the building blocks of Kubernetes and are what you use to build complex applications. A Kubernetes resource is a lightweight object that represents a single entity in the cluster. A Kubernetes resource includes information about how to interact with that entity and metadata such as its name and labels.
You can think of resources as analogous to tables in a database, where each row represents an individual piece of data. Each row has a column for each entity's attribute (or property). In this case, each attribute corresponds to one or more fields within the Kubernetes object. K8s resources include things like Pods, ReplicaSets, Services, etc. These resources define how your applications are deployed and managed within the cluster.
- A pod represents one or more containers as part of a single application. Pods share the same network namespace and can access each other's ports without proxying or port mapping. Pods also have IP addresses and can expose ports to outside connections without proxying.
- ReplicaSets ensure that a specified number of instances of the pod(s) are running at any given time. They are used to maintain performance guarantees for pods by ensuring an adequate number of pods are running at any given time to handle traffic load demands.
- Service offers a single point of access to pods in an application regardless of where they are running in the cluster.
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List of Resources in Kubernetes Namespace
The Kubernetes namespace is an essential part of the Kubernetes platform. It provides information on multiple tools and services that can help you build your custom cluster, deploy applications, manage resources, and more.
In this section, we'll explain with a kubectl list of resources what namespaces are, why they're essential, and how to use them.
1. Using kubectl, get all
This is the command for you when you want to see all of the resources in a namespace. While it may seem like a simple command, it's quite powerful. It gives you an overview of all of the resources in Kubernetes and provides information about each. The" kubectl get all "command allows you to view the status of all of your Kubernetes objects, including pods, Kubernetes deployment resources, services, and replica sets. This command is handy when troubleshooting, letting you see which objects are not running or have failed.
2. Using kubectl API-resources
This command lets you get information about specific API objects for example, pods or services within a particular namespace. For example, if you wanted to see all of the pods in your staging namespace with their names and status, this would allow you to do so quickly! The information returned by this command is similar to that returned by kubectl get but includes much more detail about each object in question (such as its IP address).
This command is useful if you're trying to understand what's already in your cluster or if you're troubleshooting an issue and need more information about what's happening inside it.
3. Using kubectl get
The Kubernetes "kubectl get" command is one of the essential commands of a Kubernetes resources list and is a tool that can be used to view all the objects in a given namespace. It's helpful if you want to know what kinds of objects are in your namespace, as well as their names and descriptions.
You can use kubectl to see details about your cluster's nodes, pods, services, and more. You can also use it to retrieve logs from a running pod or to view information about the deployment configuration of a particular application.
The kubectl get command is one of the essential tools in a Kubernetes user's toolkit because it allows them to see what's happening in their cluster at any given time.
The Kubernetes command can also be used with other parameters—for example, when you want to see only certain kinds of objects or only particular objects. For example, if you're looking for all your pods (like containers), you could use this command: "kubectl get pods."
How to Manage Kubernetes Resources?
When Kubernetes runs, you have many options for managing your cluster's resources. In this section, we'll take a look at seven ways that you can manage Kubernetes resources:
1. Organizing resource configurations
Kubernetes can be configured with a large number of resources. Keeping track of all the resources and their configurations is difficult. To make managing it easier, you can organize your configuration into multiple files and store them under a single directory in the cluster. You can then use kubectl to apply these configurations to your cluster. This practice will help you avoid confusion when working on multiple projects with different resource requirements.
2. Bulk operations in kubectl
One of the most important things you can do when managing Kubernetes resources is to use bulk operations. Bulk operations allow you to perform actions on multiple objects simultaneously, saving time and ensuring that all objects are correct. You can use them to update many different things about your infrastructure at once, like changing metadata or configuring services and deployments.
3. Using Labels Effectively
Kubernetes allows you to add metadata to your resources called labels. You can use labels to tag resources with information like what tier they belong in or region they're hosted in. This makes it easier to organize and search for resources in your cluster.
Labels are also useful for selecting specific sets of objects when you want to act on them (such as updating their configurations). For example, suppose you have an application that can be deployed only in the production environment. In that case, you can use labels to identify which objects should be updated when updating just the production pods.
4. Canary Deployments
Canary deployments are a valuable strategy for managing Kubernetes resources. They allow you to test changes in a controlled environment before rolling them out to production. This helps you ensure that there will be no unexpected side effects when you deploy the new version of your application.
Canary deployments are also helpful for testing upgrades to your cluster itself. With this approach, you can ensure that the new version of your cluster software works correctly before updating the entire cluster.
5. Updating Annotations
Annotations are a way to add metadata to Kubernetes resources. They can be used to store information about the resource, like its name and location, or they can be used to control how it behaves. One example is the default storage class, which controls how the resource is stored in persistent storage. If you change your annotation value to "standard" or "expedited", the default storage class will be updated accordingly.
6. Updating Labels
Labels are used to organize and control your application's resources. You can use them to change how resources are scaled or even change how new instances of containers are created. Labels can also be used for other purposes, like tracking costs or engineering teams.
Having suitable labels will make it easier to manage your resources, so make sure you have a plan before deploying your application!
7. Scaling Your Application
Once you've deployed your application with the right labels, it's time to scale! This is one of the most important steps in managing Kubernetes. Scaling means adding more instances of containers based on specific criteria (like CPU usage). If you don't know what scaling strategy works best for your application, consult an expert to help determine what scaling strategy will work best for your application's needs.
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Types of Kubernetes Resources
Kubernetes is an excellent tool for managing Kubernetes container resources and applications, but it can be challenging to understand how to use its various Kubernetes resource types. Here are some of the most common resources you'll encounter when working with Kubernetes:
1. CPU
The CPU resource controls the amount of processing power available to your application. It is expressed in terms of the number of vCPUs and the amount of Kubernetes resources memory per vCPU.
2. Memory
Memory is used by applications to store runtime data, such as variables and temporary objects, while they are running. Kubernetes allocates memory based on the memory request, calculated by adding up all the requests for both pods and containers and then dividing by how many Kubernetes CPUs it has.
3. Disk I/O
Disk I/O refers to the amount of data that can be read from or written to a disk. Disk I/O is essential for your Kubernetes cluster because it helps to ensure that your system can handle the amount of data you are storing on the cluster.
Disk I/O is one of the kubectl list resource types that allows you to limit the amount of disk space used by each container in your cluster.
If you set a limit on disk space, any container over that K8's resources request limit will be killed off. This will prevent your cluster from running out of disk space, harming its ability to function correctly.
4. Network Bandwidth
Network bandwidth is one of the most important aspects of Kubernetes. It allows you to allocate a certain amount of network bandwidth to various containers and Kubernetes pod resources. This can be an absolute value (e.g., 10Gbps) or a percentage of overall bandwidth.
In addition, you can set up QoS policies for different types of traffic (e.g., traffic from your database servers should be prioritized over traffic from your web servers). If you're running multiple clusters in different regions, this can help prevent issues caused by the unevenly distributed load between them.
Kubernetes Resource Constraints vs Requests
| Kubernetes Resource Limits | Requests |
|---|
| Kubernetes resource limits are the maximum value of the resource that can be requested by the user. | Kubernetes resource requests, on the other hand, are the actual values that a user requests and gets from an API. |
| Limits are generally used to protect clusters from running out of memory or CPU | Kubernetes resource requests are typically used to make sure that nodes can receive traffic even if they're underutilized. |
| Kubernetes resource limits best practices are set by the Kubernetes cluster administrator | Requests are set by your application developer. |
| Limits can be applied to node pools and replicasets. | Kubernetes resource requests can only be applied to pods and replication controllers |
| Limits can be set per pod. | Kubernetes resource requests can be set per pod or per container instance within a pod. |
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Conclusion
Kubernetes is a powerful tool that allows you to manage your container-based applications, regardless of size. It's not just for large companies with massive data sets, either. At KnowledgeHut, we have seen how tech startups and small businesses can use Kubernetes to scale their operations and improve efficiency. If you want to learn more about Kubernetes and how it can help your business grow and thrive, choose KnowledgeHut's Kubernetes Certification courses today!
