What is a namespace in Kubernetes?
Namespaces are a way to organize clusters into virtual sub-clusters — they can be helpful when different teams or projects share a Kubernetes cluster. Any number of namespaces are supported within a cluster, each logically separated from others but with the ability to communicate with each other.
What is dnsPolicy ClusterFirst?
Pod’s DNS Policy These policies are specified in the dnsPolicy field of a Pod Spec. ” ClusterFirst “: Any DNS query that does not match the configured cluster domain suffix, such as ” www.kubernetes.io “, is forwarded to the upstream nameserver inherited from the node.
What does Kube proxy do?
kube-proxy is a network proxy that runs on each node in your cluster, implementing part of the Kubernetes Service concept. kube-proxy maintains network rules on nodes. These network rules allow network communication to your Pods from network sessions inside or outside of your cluster.
What is a headless service in Kubernetes?
A headless service is a service with a service IP but instead of load-balancing it will return the IPs of our associated Pods. This allows us to interact directly with the Pods instead of a proxy. It’s as simple as specifying None for .
What is difference between Kubernetes and OpenShift?
Both Kubernetes and OpenShift are popular container management systems, and each has its unique features and benefits. While Kubernetes helps automate application deployment, scaling, and operations, OpenShift is the container platform that works with Kubernetes to help applications run more efficiently.
When using deployments it is recommended to manage ReplicaSets by yourself?
However, a Deployment is a higher-level concept that manages ReplicaSets and provides declarative updates to Pods along with a lot of other useful features. Therefore, we recommend using Deployments instead of directly using ReplicaSets, unless you require custom update orchestration or don’t require updates at all.
How do I know if DNS is running Kube?
Check if the DNS pod is running Use the kubectl get pods command to verify that the DNS pod is running. NAME READY STATUS RESTARTS AGE coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h Note: The value for label k8s-app is kube-dns for both CoreDNS and kube-dns deployments.
Is Kube-proxy a Daemonset?
Since Kube-proxy runs as a daemonset, you have to ensure that the sum of up metrics is equal to the number of working nodes. Rule sync latency: The kube-proxy is synchronizing its network rules constantly between nodes.
What happens if Kubernetes master goes down?
Master in Kubernetes is a node that controls and manages a group of worker nodes. If you have a Single-Master architecture, then it becomes a problem, if the master node goes down, and then you cannot create more services and pods, etc. and the cluster fails.
When using Deployments it is recommended to manage ReplicaSets by yourself?
Why do we need headless service?
When there is no need of load balancing or single-service IP addresses. We create a headless service which is used for creating a service grouping. So then you use Headless Service since it does not have an IP. Kubernetes allows clients to discover pod IPs through DNS lookups.