Continuing the Kubernetes v/s Docker Swarm Debate
In a previous blog, “Kubernetes v/s Docker Swarm – Which is The Right One for You?”, we talked about how there is a pressing need for organizations to have high-quality software running reliably while moving from one computing environment to another – especially as supporting ecosystems, network topographies, security policies, and storage solutions change.
Both K8S and Docker Swarm have been popular technologies used to manage containerized workloads. And although both K8S and Docker Swarm allow teams to specify the desired state of a system using containerized workloads, employ multiple hosts to form a cluster for load distribution, and seamlessly orchestrate the needs of the system and keep it running in a balanced, fault-tolerant manner, they differ in several aspects.
Since we talked about how they are different in their performance, service discovery, and deployment capabilities, let’s continue the debate by talking about a few more aspects in which K8S and Docker Swarm differ.
Flexibility of implementing external plugins
When it comes to the flexibility of implementing external plugins, Kubernetes emerges as a highly configurable and extendable option. But since most cluster administrators use a hosted or distribution instance of Kubernetes, a very small percentage of users usually install extensions or author new ones.
Yet, Kubernetes supports several customization approaches including changing flags, local configuration files, or API resources as well as extending the solution to support new types and new kinds of hardware. For instance, CNI allocates AWS Elastic Networking Interfaces to accelerate startup times while enabling large clusters of up to 2000 nodes. At the same time, since storage capacity is usually limited and depends on the node in which a pod runs, using APIs, the storage capacity in Kubernetes can be extended.
It is also important to note that although Kubernetes is deprecating Docker as a container runtime, Docker-produced images will continue to work in the cluster with all runtimes, as they always have. However, if teams are using managed Kubernetes services like GKE, EKS, or AKS, they will need to make sure that worker nodes are using a supported container runtime before Docker support gets removed in future versions of Kubernetes. When Docker runtime support is removed in a future release, teams will need to switch to one of the other compliant container runtimes, like CRI-O.
Although Docker Swarm also allows for extending its capabilities by loading third-party plugins, currently, it only supports volume, authorization plugins, and so on. Support for different types of plugins will be provided in the future.
Securing workloads and services
When it comes to securing workload and services, both K8S and Docker Swarm fare extremely well. Since security is of paramount importance in enterprise deployments, Kubernetes delivers several security capabilities such as pod security standards and policies. These capabilities allow teams to enable authorization of pod creation while also aiding them in defining privilege and access control settings for a pod or container.
Similarly, Docker Swarm also offers several key security features that allow teams to securely deploy container orchestration systems. Using Docker’s built-in swarm mode Public Key Infrastructure Systems, teams can ensure the right encryptions are in place and ensure configuration information and data are shielded from attackers. Admins can choose to protect these keys by activating the autolock feature to help to prevent encryption keys from falling into the wrong hands.
When it comes to choosing between Kubernetes and Docker Swarm, options abound. Evaluating each aspect in detail is important to make the right decision. Although both tools offer a unique set of benefits, in our opinion, it may be advisable to choose Kubernetes for complex applications and use Docker Swarm for quick and easy deployments.