Kubernetes Namespaces are a cluster-wide resource that can be used to logically group related pods and services. Namespaces provide an isolated user space for Kubernetes services, users, and deployments. A namespace can be thought of as a separate user space within the larger Kubernetes cluster. The primary use case for namespaces is to isolate users and deployments from each other. This means even if two users both have privileged administrator access to the same Kubernetes cluster, they cannot see or access resources belonging to different users. This article will explain what a Namespace is in kubernetes and how it is used.
What is a Kubernetes Namespace? #
A Kubernetes namespace is a cluster-wide resource that can be used to logically group related pods and services. Namespaces provide an isolated user space for Kubernetes services, users, and deployments. The primary use case for namespaces is to isolate users and deployments from each other. This means even if two users both have privileged administrator access to the same Kubernetes cluster, they cannot see or access resources belonging to different users. This article will explain what a Namespace is in kubernetes and how it is used. Kubernetes namespaces have a similar role to directories or folders on a filesystem: they group related resources together.
For example, in a web application running across multiple containers, the containers and the static assets like CSS and JavaScript would go into one namespace, the database that talks to a remote database server would go into another namespace, and the running application server would go into a third namespace.
Creating a Namespace in Kubernetes #
To create a namespace, you have to first choose a name for it. Namespaces must start with a lowercase letter or a number, and can only consist of alphanumeric characters and underscores. After choosing a name, create an empty namespace using the following command – kubectl create namespace my-namespace This will create an empty namespace called my-namespace in Kubernetes. You can also pass a flag -o yaml to create a yaml file with the namespace creation details. This is useful if you want to automate namespace creation.
Kubernetes Namespace Use Cases #
Kubernetes namespaces provide a way to logically group resources, users, and deployments. A namespace can be thought of as a separate user space within the larger Kubernetes cluster. The primary use case for namespaces is to isolate users and deployments from each other. This means even if two users both have privileged administrator access to the same Kubernetes cluster, they cannot see or access resources belonging to different users. Kubernetes namespaces have a similar role to directories or folders on a filesystem: they group related resources together.
For example, in a web application running across multiple containers, the containers and the static assets like CSS and JavaScript would go into one namespace, the database that talks to a remote database server would go into another namespace, and the running application server would go into a third namespace.
Confirming a Namespace exists in Kubernetes #
Confirming that a namespace exists in Kubernetes is easy, you can use the following command to see all the namespaces existing in your cluster – kubectl get namespaces You can also use the kubectl describe command to get more details about the namespace.
Important Note – You can only create a Namespace once per cluster. If you try to create a namespace again in the same cluster, you will get an error.
Limiting Pod Access with Kubernetes Namespaces #
Pods are the smallest deployable units in Kubernetes. Every Kubernetes deployment has to be created inside a Pod. Controlling access to Pods based on Namespaces can be useful in a variety of use cases.
For example, you may want to prevent one group of users from accessing the database hosted in your cluster. You can do this by creating a Namespace and assigning the database resources to the Namespace. This will prevent the users in that group from accessing the database. Additionally, you can also use Namespaces to create a shared database between two or more groups.
For example, if two teams work together on the same application, but store their data in different databases, you can use Namespaces to share the database between these two teams. Each team will be able to access their database, but will not be able to access the remote database.
Key takeaway #
Kubernetes namespaces provide a way to logically group resources, users, and deployments. A namespace can be thought of as a separate user space within the larger Kubernetes cluster. The primary use case for namespaces is to isolate users and deployments from each other. These namespaces can be useful for many use cases, such as creating a shared database between two or more groups and preventing one group of users from accessing the database.
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