A Look At Alternatives to Docker

Docker is a well-known, Linux-based, open-source platform for developing, testing, deploying, and managing stable applications. Many organizations already use Docker's containerization technology to share their product across a virtual production environment.

However, some developers are having difficulty using Docker containers during their app development processes. As a result, many Docker alternatives capitalized on these challenges.

Why Should You Choose a Docker Alternative?

Docker's software container is flexible, easy to deploy, and does not demand much from system resources. Docker works with significant programming communities across the world to ensure the constant development of its programs. Additionally, Docker is the leading software for visualized app development - so why should you choose an alternative software?

As mentioned earlier, developers are facing various challenges with the Docker platform. One of the biggest challenges is data storage. Once you shut down a container, all data held there is wiped. To prevent this, developers must save data to a different location. Docker has addressed this issue, but developers are still experiencing difficulties.

Additionally, the Docker daemon will refuse to run if you do not give it root privileges.

In this article, we will take a look at ten different alternatives to Docker.

Podman

The first Docker alternative is Podman.

Podman is an open-source virtualization platform developed by RedHat. Like Docker, you can use Podman's container software to develop, test, deploy, and manage OCI containers on a Linux-based platform. However, Podman is daemon-less and does not require root privileges to run. Containers can run in the background since it integrates directly with the system daemon.

Podman's lack of a daemon improves its flexibility as a container software because it removes the dependency on a single process that may be a point of failure that disseminates to child processes prompting them to fail. It also gives you a considerable security advantage since it relies on user privileges. Containers without daemons are less prone to attacks since the container is running under user privileges. Any attack would have to be done by the user.

Podman also has greater integration with developer tools than Docker, which is a huge plus.

For developers looking for higher security, better compatibility, and more developer tools, Podman is the better option.

LXC (Linux Containers)

LXC is an older containerization technology that allows users to create several isolated Linux environments on a single machine. Despite being an older model, it is making a solid comeback by taking advantage of Docker's shortcomings, including:

• reduced disk performance
• poor volume management
• sharing host resources (like IP addresses and system files)

LXC is lighter than Docker and uses fewer system resources while also providing more security options.

LXD

LXD is another open-source container engine. It is designed explicitly for LXC Linux containers. LXC allows users to run apps in isolated containers without managing individual kernels. LXD provides an interface to connect to the LXC software library, which creates a daemon that handles:

• networking
• data storage
• managing several LXC containers

LXC can run as a standalone tool, but it has limited features. LXD provides additional features. They operate together in a subsection of container technology and have a limited number of users. LXC/LXD is more suitable for projects that require long-term virtual application runs rather than those that use short-term containers.

LXC/LXD is a great alternative to Docker because it can run multiple processes. However, unlike Docker, LXD only supports Linux and cannot run on Windows or OS X.

Containerd

Containerd is a high-quality container platform that runs RunC to provide an interface between OS and container engines. RunC is a Windows daemon with Linux support that abstracts OS-specific functionality to make running, supervising, and managing containers easier. The abstraction Containerd provides eliminates the complexity that several low-level system calls involve.

However, Containerd does not handle image building or volume creation.

OpenVZ

OpenVZ is an open-source container-based virtualization tool for Linux. Virtuozzo developed it, and it is similar to Docker in terms of features and functionality but offers more than just application deployment.

OpenVZ lets users create several isolated containers on a Linux server. The containers are used to create remote environments for hosting Virtual servers. Each container acts as a single server with independent root access, memory, IP address, system libraries, apps, and files. This is good because it prevents applications from conflicting with each other and allows them to be launched independently.

Additionally, OpenVZ's Network File System (NFS) lets users access network disk files remotely. System and network administrators can use the NFS to move and share between virtual and physical servers.

VirtualBox

VirtualBox is another great alternative to Docker. It was released in 2017 and is similar to Docker in that they are both virtual platforms that developers can utilize to create and fun applications. Unlike Docker, VirtualBox enables users to create and run multiple virtual machines across different operating systems.

VirtualBox is a favorable choice for developers that want their apps to run on different operating systems.

While VirtualBox is not as portable as Docker and other alternatives on this list, the benefit of running any OS on a single machine makes it a valuable option.

Kubernetes (K8S)

Kubernetes (commonly called K8S) is a popular alternative to Docker. Developed by Google, Kubernetes is an open-source container automation system. It allows you to manage applications in physical, virtual, and cloud environments. K8S can control thousands of containers at a time.

If you are planning to run multiple containerized apps, you will need K8S. And no worries about group privileges, as it uses a built-in isolation mechanism similar to namespaces.

Microsoft Azure Container Registry

Microsoft Azure Container Registry is a private Docker registry that is responsible for storing and managing container images. It offers better security options than Docker, including vulnerability scans and runtime protection.

Developers looking to manage container clusters should choose Microsoft Azure. It allows developers to migrate from Monolithic architecture to containers efficiently. It also makes container management easy for non-experts.

Microsoft Azure also has powerful visual studio tools for debugging and deploying containerized apps, making sharing images and deploying container services much more effortless.

Rancher

Administrators may find it challenging to manage multiple large groups of clusters. Rancher is an orchestration software for managing container clusters using automation.

Also, unlike other Docker alternatives, Rancher helps manage groups of other orchestration engines like K.

Rancher is a powerful tool that helps developers manage and automate any cluster processes created by Kubernetes and similar engines. Corporates that utilize Ranger enjoy having a production-ready K8S platform, automated deployment, and decreased overhead management.

Vagrant

The final Docker alternative on this list is HashiCorp Vagrant.

Vagrant is a valuable tool for replicating multiple virtual environments across various virtual machines and operating systems. Users can set up virtual environments that are replicated across different networks and operating systems. With Vagrant, you can avoid the "but it works on my computer" situation in app development.

Vagrant runs on all notable virtualization platforms, like VirtualBox and cloud platforms. You can create images and share them across various platforms to create duplicate virtual environments. This is different from Docker, which resets to the old image after restarting.

What is the Best Alternative to Docker

Any of the listed Docker alternatives can serve as an excellent alternative. Each option features its own strengths and weaknesses and also addresses specific shortcomings associated with Docker.

It is not possible to declare any one alternative as the best. The absolute 'best' alternative depends on the users' individual needs.

However, if you are searching for a Docker alternative with similar features and functionality but without root privileges - Podman is a perfect choice. On the other hand, users who want to run different operating systems on the same system will use VirtualBox.

Regardless, these Docker alternatives are free to use, although there may be fees for premium services.