Planning and coordinating all of your architecture’s components with both present and long-term plans in mind is necessary when delivering applications at scale. Across multiple clusters, the management of the microservices is automated with the help of container orchestration tools. Here below are the two most famous container orchestration tools.

Two names stand out as open-source leaders in container technologies:-

• Kubernetes
• Docker

Even though they are distinct tools that enable users to manage containers, they work best together and alone have significant capacity. Before knowing these two in detail, let’s learn about some basic things like containers. Both Kubernetes and docker Swarm are container orchestration frameworks.

What are Containers?

Containers are software packages with all the necessary tools to operate in any environment. Containers dematerialise the operating system in this manner, allowing them to execute on a developer’s computer, a public cloud, or a private data centre.

As we know, the number of containers in any enterprise application can increase or decrease per the organisation’s needs. Therefore, orchestrating containers having containerised applications is very important.

What is Kubernetes?

Kubernetes is an open-source tool that makes deploying, scaling, and managing containers easy. Google Kubernetes is a highly versatile tool that can help you deliver even the most complex applications reliably. It is a container orchestration tool.

Components of Kubernetes architecture

• Kubernetes Pods
• ReplicaSets
• Deployments
• Services
• Ingress
• Namespaces
• Clusters
• Secrets and ConfigMaps
• Data Volumes
• PetsSets
• Nodes – Control plane, also called a Master node, and Worker Plane called Slave node.

Pros of Kubernetes

• An active open-source community develops it. The development of the code base is monitored continuously and actively.
• Automated load balancing, service discovery, ingress, automated rollouts/rollbacks, horizontal scalability and storage orchestration are some of the key features offered by Kubernetes.
• Kubernetes offers self-healing of the entire cluster or Kubernetes cluster.
• smart scheduling
• Kubernetes is adopted widely in the market.
• Google and IBM have tested Kubernetes, and most operating systems support Kubernetes without any issues.
• Cloud tool vendors like LogDNA, Sysdig, Portworx, and many others largely support them.
• Kubernetes organises KubeCon conferences every year to provide its users with more insight.
• Kubernetes provides strong guarantees on the cluster state and a single set of APIs.
• Big cloud providers like Google Cloud Platform, Microsoft Azure, AWS, and IBM Cloud offer managed offerings. For on-premise use and public clouds, Kubernetes is available.

Cons of Kubernetes

• Managing a Kubernetes container image requires a good understanding and knowledge, and Kubernetes has a steep learning curve.
• Individual developers cannot set it up for simple apps and occasional deployments since it is too cumbersome.
• The teams often require continuous Integration/ Continuous Deployment(CI/CD) workflows, services and other tools like Kubectlare.
• DevOps practices for managing access, governance, identity and security are also requirements of the team while working with Kubernetes.

Installation

Even though Kubernetes has a variety of installation choices, it is recommended to have a fundamental knowledge of the platform and cloud computing before installing it.

Installing Kubernetes requires downloading and installing kubectl, the Kubernetes Command Line Interface (CLI):

• Kubectl can be installed on Linux systems via curl, native, or other package management techniques as a snap application.
• Curl, Homebrew, or Macports are all suitable methods to install kubectl on macOS.
• On Windows, kubectl can be installed in various ways, including via curl, the Powershell Gallery package manager, Scoop command-line installer or Chocolatey packet manager.

What is the Docker Swarm?

Like Kubernetes, Docker is also a container orchestration tool or a source container orchestration platform for docker containers. For docker’s native support, there is a swarm mode managing multiple containers of clusters.

Swarm management nodes deployed using Docker Engine serve as the cluster’s orchestrators and managers, and worker nodes make up a Swarm cluster (Manager nodes direct the swarm cluster to execute tasks).

In swarm mode, the docker engine is connected with other instances of the docker engine. The docker enterprise has developed it. We can manage the docker swarm, enable interfaces and initialise using the docker command line interface(Docker CLI).

We can also use the docker command line interface to join and leave the docker engine. Applications running on multiple nodes sharing the same container are only possible because of the docker swarm.

Components of a docker swarm, docker compose, docker containers, docker-engine

• Swarm nodes:- Manager node and Worker node
• Docker services
• Docker tasks

Pros of Docker swarm

There are various docker swarm benefits. Following are some of the advantages of using docker swarm:-

• Docker is basically a container orchestration platform where one can deploy applications in a containerised form. Swarm is built to be used with the docker engine, which is already a part of that platform.
• Installing and setting up the docker swarm is straightforward.
• Swarm API is the docker API of the docker swarm.
• Existing docker tools can be used with docker swarm.
• Docker CLI and docker-compose can be seamlessly integrated with the docker swarm because the same command line interface is used as the docker engine.
• Docker Swarm lets you choose the suitable cluster node to deploy your application. It is done through intelligent node selection using a scheduling and filtering system.

Cons of Docker swarm

The following are the disadvantages of using docker swarm:-

• Extensions are customisations offered by the docker swarm that is limited.
• The automation capabilities of the docker swarm are less in comparison with Kubernetes.
• Docker Swarm offers less functionality than Kubernetes.
• In a DevOps pipeline, the separation of Dev-Test-Prod workloads is complex.

Installation

Installation of the docker swarm is much easier and simpler than Kubernetes. First, install a docker engine on a machine. Now, one can deploy a docker swarm as easily as:-

• IP addresses are getting assigned to the hosts.
• Establishing the necessary protocols and ports.

Docker Swarm vs Kubernetes: Fundamental differences

Now, we will discuss some significant differences between the docker swarm and Kubernetes in each perspective, like GUI, networking, etc. Therefore, let us discuss them sequentially in detail for Kubernetes vs docker.

Both Docker Swarm and Kubernetes are productive solutions for:

• Implementation
• Deployment of applications at a large scale
• Management

Allowing automation of application authority effectively and scaling both models shatter applications into containers. Some basic summary of their dissimilarity are mentioned below:-

• Kubernetes also centres on open-source and modular orchestrations to pursue high-demand applications with intricate configurations by providing a structured container orchestration solution.
• In contrast, Docker Swarm creates the most acceptable basic applications, which are simple to manage and fast to deploy, emphasising ease of usage.

Now, we will be discussing the fundamental differences between Kubernetes and Docker sectionally.

Application Definition and Deployment

Kubernetes

Renovating ReplicaSets and Kubernetes Pods representing upgrades to application states is involved in the deployment of Kubernetes. By explaining a pod’s requirement state, the present state to the required states is modified by a controller at a balanced rate.

One can elucidate each side of an application’s life period with the help of Kubernetes deployment. These points involve:-

• Pod count
• How to use images
• Updating pods

Docker swarm

To configure a Docker Swarm application, one may use predefined Swarm files to define the application’s required state. The YAML file must be copied to the root grade for deployment or the Docker Compose File.

Organisations can run containers and services on Swarms that include various node machine features by utilising:-

• Machines of different types
• Networks of any size

GUI(Graphical User Interface)

Kubernetes

Kubernetes provide a simple solution to monitor all the container images and other resources, and that is a web dashboard. That web user interface provides various features and helps with the following:-

• They are managing containers and their resources.
• Deploying containerised applications on the Kubernetes cluster.
• For impactful troubleshooting, it shows the error log and provides detailed information about the state of the resources of a cluster. It includes DaemonSets, deployments, jobs, etc.

Docker Swarm

For deploying containers and orchestrating docker containers, docker swarm users do not have a web-based dashboard like Kubernetes. We can also use third-party tools or applications to have feature-loaded graphical user interfaces for the docker containers.

Following are some of those user interface tools for docker swarm:-

• Swarmpit
• Dockstation
• Portainer
• Shipyard

Availability

Kubernetes

By allowing two topologies by default, Kubernetes provides clusters to remove a single side of failures created by high availability.

• A cluster can be made available using Stacked Control Plane nodes that co-locate etcd objects during a failover with all available nodes.
• In addition, external etcd objects can be used as a load balancer while separate control plane nodes are controlled.

Both methods rely on kubeadm and a Multi-master approach to keep the etcd cluster up and running. This is accomplished by keeping the cluster nodes externally or internally within the control plane.

Docker Swarm

Docker maintains high availability by replicating services at the swarm nodes level. A swarm manager will deploy multiple copies of the same container. By default, an Internal Distributed State Store is configured as follows:

• The swarm manager nodes are to be controlled to control an overall cluster.
• Load-balanced container instances and highly available are formed by worker node resources, supervised by the internal distributed store.

Scalability

Kubernetes

Kubernetes carry autoscaling on both:

• The pod level, with Horizontal Pod Autoscaler
• At the cluster level, through Cluster Autoscaling

Kubernetes exploit an all-comprehensive network for divided nodes, as well as solid guarantees in the duration of unified API sets and cluster states are provided.

Essentially, Kubernetes includes designing new pods and programming them to nodes with available resources.

Docker Swarm

By deploying containers quickly, Docker Swarm provides the orchestration tool with quicker reaction duration, which allows scaling on demand. Reproducing the types of connections to the application involves scaling a Docker application to control high traffic loads.

Eventually, one can effortlessly scale your application up and down to further higher availability.

Networking

Kubernetes

In Kubernetes, networking is done efficiently in an inter-clustering networking manner. Kubernetes creates a peer-to-peer, flat connection for the communication between node agents and pods. The network policies regulate the communication between the pods at the time of assignment of the unique IP address to each of them.

The Kubernetes networking concept needs two Classless Inter-Domain Routers to construct a subnet.

The two CIDRs are required for the following:-

• One for addressing the IP of the node.
• Second, for other additional services.

Docker swarm

When a node joins a Swarm, Docker Swarm generates two different types of networks. Following are the two different sorts of networks created by the docker swarm:-

• The first kind of network depicts an overlay of all available services.
• A host-only bridge is created by the second network for all the running containers.

A multi-layered overlay network allows for peer-to-peer distribution among multiple host machines, enabling encrypted and secure communications.

Monitoring

Kubernetes

Kubernetes offers various native logging and controlling solutions for deployed performances inside a cluster. These settlements control performance by:-

• services, pods, and container inspection
• Observing a cluster’s behaviour as a whole

Furthermore, a third-party combination to help with event-based is also supported by Kubernetes controlling involves:-

• InfuxDB
• Sysdig
• ElasticSearch/Kibana
• Grafana

Docker Swarm

Unlike Kubernetes, Docker Swarm does not offer a controlling solution right away. Consequently, one has to depend on third-party applications to help control Docker Swarm. In conclusion, it appears to be a complicated scenario to monitor a Docker Swarm due to the sheer amount of cross-node things and services compared to a K8s cluster.

Several open-source monitoring tools which generally support attaining a scalable monitoring solution for Docker Swarm involve:-

• cAdvisor
• InfluxDB
• Grafana

Summary

The purposes of both Kubernetes and Docker imbricate each other. We have discussed some fundamental differences between these container orchestration platforms. Both of them are helpful and related to each other. I hope you have got a basic understanding of the differences between the Kubernetes and docker swarm.