A pod is a group of containers and is the smallest unit in Kubernetes, it can have one or more containers, usually if there’s multiple containers in a pod is because they are strictly tied.
[!IMPORTANT] Containers in a pod share the same ip address and can communicate trough
127.0.0.1without extra configuration.
A Deployment is basket that holds multiple pods, it orchestrates how they scale and how they update/create basically it defines the life cycle of our pods
[!NOTE] Deployments are a subset of replica sets
A service exposes our deployments to other resources inside our kubernetes cluster, a service is required because a deployment by itself cannot communicate with other resources without a service.
A node can either be a physical or virtual machine that runs kubernetes resources
A cluster is a group of nodes, fundamentally its composed by at least a master node and one ore more worker nodes.
Selector keywordA Cluster IP is a kubernetes resource that provides internal IP addresses to make services across our cluster accessible to each other.
A node port helps us expose a service on a static port from the range of 30000 to 32767, users can access the service trough [NodeIP]:[NodePORT], as far as i know this is only useful for Dev/QA purposes.
A load balancer is a kubernetes resource that provisions public IP addresses to expose our services, to the outside world.
It requires a cloud provider load balancer like:
[!NOTE] If we are running a managed kubernetes cluster in our own servers, we require a custom load balancer like MetalLB otherwise we cannot expose our services to the public.
An Ingress Controller is a component in Kubernetes that manages external access to services within a cluster. It is responsible for routing HTTP and HTTPS traffic based on the rules defined in Ingress resources.