The web overflows with applications, each having a different function and a completely different feature set than the previous one. Each of these applications can work with different developmental environments, but rather than installing the application separately each time; we can use a container.
A container is a package containing software and all the essentials, such as libraries, binaries, and additional software required to run it in a completely new environment with completely different hardware components. Containers make our operating system portable and more efficient.
With containers, the scalability of the Internet as a system becomes infinite. Containers allow devices to share memory, network resources, and storage and offer a logical mechanism for extracting software from their home environment. This concept is the groundwork on which cloud computing is based.
What is Docker?💁
Docker is a containerization platform concerned with packaging applications with all their required dependencies in a container.
It provides an isolated and consistent environment to all the containers so that each of the software packed in these containers gets to interact independently with its environment without the intervention of some other software.
It deploys containers very fast and has a flexible and intuitive interface. It has an inbuilt control system that allows users to edit the images and version control them immediately.
This Linux-based open-source containerization platform is one of the most impressive feature sets and largely used platforms. But this immensely coveted containerization application is not the only one of its type in the market.
So in case of technical difficulty or if you need a platform with a different feature set, here is a list of some Docker Alternatives.
Best Docker Alternatives – Our Top Pick👌👌
Docker, with its impressive functionality set and immensely flexible and intuitive interface, may appear to be the ultimate choice when selecting a containerization platform which is true to some extent.
But it should also be noted that there are various container orchestration tools in the web development scenario with a similar or maybe even a slightly better feature set than Docker.
Here is our list of some of our favorite platforms to make your work of searching for an alternative platform a little bit easier.
1. Podman – Docker alternatives open source
Podman is one of the best Docker Alternatives and an open-source, all-in-one container engine that can develop, monitor, and run containers. The engine is compatible only with Linux machines. It has a simple interface makes dealing with system security rules very easy.
It has a CLI interface. Podman supports multiple container image formats and even fully manages these images. Because it is an all-in-one container engine, it can manage the entire container life cycle from packaging to running, restoring, and removal.
It has a standard command prompt for each step of the containerization process (skopeo, runc, buildah, etc).
These tools can work on any OCI-compatible engine. Podman even manages container networking using slirp4netns and Netavark. It even facilitates sharing of resources between groups of containers and pods and also supports running containers without root or other elevated privileges.
A feature of Podman that makes it stand out greatly from Docker is that it is Daemon-less. A daemon background program ensures the requests and services are delivered without a user interface.
Rather, Podman launches its containers as a subprogram. At the same time, Docker uses a demon to run requests and services called Dockerd. Daemon not being pre-installed in Podman enhances the flexibility of the platform.
It is a powerful and multi-faceted platform with an interface designed keeping in mind the user’s convenience and can be used solo as well as in conjunction with Docker.
Want a container orchestration tool that makes the management of containers simple without sacrificing functionality? Then Kubernetes may be the software for you.
Kubernetes is an open-source containerization platform that facilitates containers’ deployment, management, and creation.
Kubernetes has an array of automatic services which, for other platforms, are done by the user. Along with managing and maintaining containers, it also offers services that ensure the safety and security of the container.
Kubernetes is also equipped with handling greater clusters of containers and allows sharing of resources between groups of containers.
This being one of the best Docker alternatives, monitors its nodes’ activity and regularly updates them on the nodes’ status. You can even add the storage system of your choice to Kubernetes.
There are also some lesser-known features of Kubernetes. Its custom scheduling feature allows you to add a custom schedule for assigning your pods to nodes. You use the custom controller feature to customize almost every package aspect. The controller even lets you manage deployments.
If you want to add a container to run as a proxy, even that is possible in Kubernetes. You can use this container to expose data to other containers or direct the data to be mounted.
Want to restrict the number of pods in a container? You can do that by using the PodDisruptionBudget(PDB). This feature is used when you want to ensure that a minimum number of pods stays active during upgrading or maintenance.
However, when using Kubernetes, some things should be kept in mind. Suppose you are a newcomer not familiar with the infrastructure of container orchestration tools. In that case, Kubernetes can be an overwhelming experience and hard to get used to, reducing its users’ productivity. Kubernetes is a powerful tool mostly aimed at container management on a massive scale.
But if you are not developing anything for a large-scale project, then Kubernetes can be completely overkilled for you, with complex tools that will barely be useful.
However, if you are looking for a container orchestration tool that is custom created for large-scale enterprises, this is the package for you.
Based on the Chromium Native Client of Google, ZeroVM is an open-source lightweight virtual environment. Instead of creating an entirely virtual environment, ZeroVM isolates individual processes that make up the environment and then implements those separately without the support of an operating system or kernel.
ZeroVM is also amongst the best Docker alternatives and very fast in starting up owing to the separate processes working a lot better individually. It also provides a high level of security, making it very suitable for running potentially corrupted code in a multi-tenant environment.
ZeroVM decomposes the code in micro-processes which helps you avoid cache problems and memory leaks. It is immensely secure and reliable owing to its two-step security, where the two steps are static binary validation and limited system call API.
Static validation protects from potential harm that may be caused by corrupted code. ZeroVM can even run C, C++, Luca, and python codes. It works well when embedded in systems because of its reliable and lightweight nature.
It aims mostly at virtualizing individual components of a system and implementing them individually rather than as a cohesive unit—all the while keeping it lightweight.
It does so by removing most of the excessive features that are not needed immediately and focusing on the features needed to make the app work.
4. Containerd – docker alternatives for Kubernetes
Containerd is an OCI-compliant independent container runtime application focusing more on embedding than a full-time container management system. It is mostly an entry-level platform that provides an interface between Operating Systems and container engines.
Containerd makes it easier for alternative platforms like Kubernetes to access ‘low-level’ Docker tools. A derivative of some kernel features in Linux; Syscalls are used to set up the containerized environment.
It acts mostly as an interface between container engines and Operating systems because of which it is mostly used by other software programs to run containers and manage container images.
It also manages a container’s complete life cycle from creation to execution. Other prominent features include OCI runtime Spec support, Image push and pull support, and OCI Image Spec Support.
It also allows CAS storage for global images in a multi-tenant system and the creation, deletion, and modification of interfaces using network primitives.
Containerd is by no means heavy-duty container management and handling, but it can provide reliable entry-level platforms for managing your containers.
When you embed Containerd into a system that provides supervision, image distribution, local storage, and network management interface can be used to its full potential.
OpenVZ is an open-source containerization software. It is compatible only with Linux machines. This is software that maximizes resources; instances are deployed in a machine in the form of containers.
OpenVZ is an operating system server technology based on the Linux kernel. It containerizes the components of the kernel into individual containers, which are used by all the guests on the device, each of the containers using the same OS, thus creating a link between the kernel and the OS.
This allows the speed of the software to go up greatly as there are no overhead losses. It has a very low memory footprint because the OS is linked to the kernel and is perfect for VSes with low memory storage.
Root access is given to every container. As a result, you can create as many containers as you want with the software. OpenVZ also proves to be amongst the best Docker alternatives that provide facilities such as management tools, cloud storage, and dedicated support, making it a perfect platform to develop and access apps.
However, when using OpenVZ, you cannot install your OS; only templates can be used, and all kernel modules may not be available. As with all the virtualization, the network port and CPU are shared with all the VPSes.
There is also a lack of versatility in OpenVZ; integrating the OS is impossible, and functionality is limited to Linux. But if you feel these problems don’t bother you or can work around them, you can use them as your virtualization tool.
LXD is an open-source container management tool. It is only compatible with Linux machines. LXD boasts of one of the software with the best functionality in the container management scenario, which facilitates building and managing Linux containers. It works on a CLI(Command Line Interface).
A highly scalable tool, LXD can support cloud platforms. It is a highly secure and reliable tool that improves its security through end-to-end encryption and resource restrictions.
This tool also updates the user regularly on the functioning of the containers and is capable of solving any minor error that occurs during the running of containers. It facilitates the migration of containers among hosts and even allows sharing of resources between groups of containers.
Among the many essentials packed with the main software in containers in LXD, are some additional elements like the file management system roots, device references such as disks and network interfaces, and some other properties. LXD improves on the features of LXC to obtain a highly functional tool that can rival the best in the market.
LXD can be a worthy alternative to Docker, but it must be noted that LXD does not include an application delivery network as found in Docker. So these two cannot be considered one-to-one replacements.
Where it creates instances comparable to ones created with Virtual Machine(VMs), each working on its own full-fledged Linux OS; on the other hand, Docker creates containers that are stateless and have minimal resources. It depends on what kind of feature set you want from your container management tool.
Rancher is a container management system that makes creating and deploying containers in any infrastructure very easy. It is a free and open-source platform, but there is a fee for support; for this, you need to pay an annual subscription fee.
Rancher allows you to manage the Kubernetes cluster right from the console. You can back up, add replacing nodes, and download the latest versions of such Docker alternatives all right from the console.
Rancher also provides solid security across the containers; it uses external security methods such as LDAP and has a solid RBAC system, allowing it to integrate users’ permission with such systems.
When managing and handling containers, you can use all the easy-to-use console features of Kubernetes and Mesos available with Rancher.
Some other additional interesting features of Rancher would be that it can be installed on any machine that runs on Docker. It provides containers with multiple environments right on the premises of the platform, thus allowing users to control multiple platforms with one tool.
A rancher is a great tool for managing Kubernetes clusters and DevOps teams. Though using the software when there is a single cluster may not be useful. Owing to its diverse functionality, Rancher may also not be the simplest tool to understand, especially for a beginner.
But if you are a seasoned professional who needs a highly functional containerization platform that can also manage Kubernetes clusters, then Rancher may be the platform for you.
BuildKit is a second-generation in-image building engine. It has lately been provided as a feature in new versions of Docker. It also uses a daemon like Docker but, unlike BuildKit, offers a parallel build processing as opposed to each layer at a time approach of Docker.
BuildKit can be best used to boost your development environment, with the easy enabling feature being a huge advantage.
Some of BuildKit’s most prominent features are; efficient instruction caching, where all the previous instructions are stored in the tool’s cache memory, and when that same instruction is given, instead of repeating the steps, you can simply search through the memory and access the instruction.
The output of execution can be obtained in multiple formats. BuildKit also enables storing and using of cache using container repositories like DockerHub, to use cache data to rebuild every feature of an image.
A command-line interface tool used for creating and running containers according to OCI specifications. The package can run on a machine with a Linux OS. A lightweight open-source package that was formerly a part of the Docker architecture.
RunC improves container portability. It is used in container engines to improve container runtime. The now-independent tool can be used as an interoperable, standardized container runtime for DevOps teams.
RunC is one of our favorites in this list of the best Docker alternatives that can scan and fully support Linux namespaces and provide support for all security features of Linux. It is a reliable and sturdy tool, especially regarding development in isolated environments and quick testing.
With most of the Docker plumbing code, RunC, even when used with Docker, has no dependency on the platform; it always functions as an independent unit.
RunC was designed with the ambition of making standard containers available everywhere. And the portability and large-scale production capability of RunC confirm that for itself.
✅FAQ on docker alternatives
What are the alternatives for Docker?
Some of the alternatives for Docker are:-
Buildah- it is open and free software. It is available on GitHub for Linux distribution.
BuildKit- BuildKit provides build processing, which improves performance and results in faster build-ups
Containerd- It’s also available on Linux, and dockers also use this. It enables Kubernetes and provides an accessible interface to runtime.
Is Kubernetes a docker alternative?
Open-source orchestration tool Kubernetes offers an API to regulate where and how those containers will run.
It enables you to execute your Docker workloads and containers while also assisting you in overcoming some of the operational challenges that arise when scaling many containers distributed across several servers.
Is Docker becoming obsolete?
The K8 contributors announced the deprecation of the Docker runtime as of version 1.20 on December 2, 2020. The Container Runtime Interface (CRI), which expands compatibility for a wider range of container runtimes rather than relying on one, is replacing the concentration on Docker as the runtime for containers.
Is Docker the future?
Docker has been predicted as the virtualization industry’s future. With businesses like Netflix, Spotify, PayPal, and Uber embracing the containerization system, its popularity is undoubtedly rising. Docker works on containerization Engines.
What is Docker used for?
Docker may dramatically speed up your app development process, but not always the app itself. The single instance of your program will often be slightly slower than without Docker, even though it aids in making it scalable so that more users can use it.
Does Kubernetes use Docker?
The Kubernetes server is a single-node cluster that runs locally within your Docker container and has no configuration options. It only performs local testing and runs on your local machine within a Docker container.
Why is Docker removed from Kubernetes?
While Containerd and CRI-O are popular choices for that runtime, Docker was not intended to be integrated with Kubernetes, creating issues.
The Container Runtime Interface, or CRI, is not supported by Docker. If it were, we would not require the shim, and this situation would not exist.
What is the difference between Docker and Kubernetes?
Docker is a utility designed for packaging and running containers. It helps you build standard containers that include all essential components required to function in isolation, such as code, dependencies, and libraries.
On the other hand, Kubernetes is an open-source toolset designed to automate application life cycle duties. It can be used to deploy, manage, and scale containerized applications.
Kubernetes can orchestrate and manage all your container resources from a single control panel. It also helps network, security, and load-balancing across your Kubernetes nodes.
Since both these products serve different purposes, they are often used together.
Can Kubernetes run without Docker?
The answer is yes and no. Kubernetes is used to manage containers, and Docker helps you build containers. So, if you won’t use Docker, you need to use any other tool to create containers, such as Podman, OpenVZ, or anyone else.
Kubernetes is a kind of management utility tool that allows you to manage containers, and if you don’t have containers in the first place, Kubernetes will have nothing to manage. So yeah, even though you can use Kubernetes without Docker, you have to use any service or tool to help you package and run containers.
What is the difference between Docker and AWS?
Docker and AWS are both similar kinds of tools that are used to deploy software applications on a server.
AWS is a cloud-computing platform that offers a wide range of on-demand services and functionalities such as storage, databases, data warehouses, analytics, servers, disaster recovery, etc.
On the flip side, Docker is an open-source virtual computing environment that lets Windows and Linux systems run in isolated containers. It is mainly used to automate the deployment of applications in containers on servers.
While both are similar tools, they are designed to serve different purposes and are not competitors. AWS can be considered a service provider, while Docker is more like an application developer toolkit.
How is Docker different from VM?
Docker is a container-based technology that creates containers on the host OS kernel. Containers are nothing but a set of processes entirely isolated from the rest of the system. It is mainly designed to run applications.
Conversely, a Virtual Machine is not based on container technology. Instead, Virtual Machines are made of user space along with the Kernel space of the operating system. Virtual Machines virtualize the server hardware, and each VM has its operating system and apps.
Virtual Machines are comparatively slower, take more boot time, and use more CPU resources than containers.
Conclusion on docker alternatives
Every package or tool mentioned in this list has unique features. Docker is a containerization tool gifted with functionality and flexibility. But that doesn’t stop its alternatives in the market from having any less of a less competent feature set.
Finding the container orchestration tool that works best for you is majorly subjective, dependent on what task you need the tool for and which web development framework you are aiming for.
Whether you value utility over functionality or vice versa, or are you looking for something more lightweight and hassle-free? I hope this list of ours helped you see your options better.