Nowadays, container orchestration is extremely important. If you only have one host, it allows you to focus on your development and production environments; however, there is so much more that you can do if you have more than one host.
Previously, starting applications needed a routine and, to be quite honest, it was a mess. There were too many ifstatements, as well as corner cases and workarounds. The entire process was a pain that everyone assumed couldn’t be avoided.
That’s when Chef, Puppet, and Ansible came out, which introduced a continuous integration and deployment. As a result of this, developers and employees don’t need to worry about the useless and tedious details of deploying an application; instead, it just deploys.
A container, similarly, normalizes the environment and aids us to abstract away of the base operating system and hardware. A container orchestration does the same thing, meaning it provides freedom to not think about which server will host a container or how that container will be handled, started, monitored, and killed.
Although every container orchestration does the same thing, there are different solutions and approaches to problems.
In a swarm, there are managers, workers, services, tasks, and key-value stores. The role of managers is to distribute various tasks across the cluster. That one manager will orchestrate the worker nodes that make up the swarm. You can think of workers like those of a department store; they work on what the managers assign them to. The services are the set of Docker containers running across the swarm of an interface. The tasks are performed by an individual Docker container which is running a given image, as well as commands needed by a service. The key-valued store stores the swarm’s state and provides service discoverability.
Kubernetes containers are based on Google’s fifteen years of running workloads at large scale productions. It’s not an open sourcing or a copying of Bourg; however, it does utilize lessons which were learned from running Borg. Kubernetes architectureuses masters, minions, pods, services, replication controllers, and labels. The master is, by default, handles API calls and assigns workloads. Minions are the ones which run workloads that the master does not handle. Pods are units of computer power and are made up of containers. Services are load balancers for pods and they provide a floating IP.