Container software provides an environment for containerized applications to run with a variety of features including storage, automation, and management. By isolating applications from the surrounding environment, containers and container software provide greater flexibility for workloads in data centers: they can run on more servers.
Containerization, which has grown in popularity in the past few years, is another step to creating agility in data centers. The faster workloads can move to environments that best support them, the more efficient the data center and the enterprise can operate.
The Open Container Initiative (OCI) is a project intended to create container specifications, so that organizations are able to use containers without lock-in or fluctuation. Such a standard makes containers more universal and flexible. Many large tech companies, including some who offer container services, have sponsored the OCI.
- Differences Between Container Solutions
- Containers vs. Virtual Machines
- How to Choose Container Software
- Best Container Software Solutions
Differences Between Container Solutions
Container software solutions differ slightly in intent. A container engine is software that holds and runs containers. Docker offers container engines. A container orchestration platform or system provides automation, health checks, and additional management capabilities; Kubernetes is one of the best examples. It handles multiple deployments and clusters and automates container behavior based on application needs in data centers.
Managed container platforms include as-a-service solutions that typically run in cloud environments. Google Kubernetes Engine (GKE), one of Google Cloud’s solutions, is an example of a container management environment.
Containers vs. Virtual Machines
Virtual machines started the application virtualization trend. Containers continue it and, in some situations, improve upon it. Virtual machines require a hypervisor to run on a server; each virtual machine has its own operating system. Containers instead share the server’s one operating system or kernel.
For businesses that need to isolate applications and run them on a greater variety of machines, containers are the better choice. Container solutions also differ in how many tasks they manage, so that enterprises can choose which software is most appropriate for their application management needs.
How to Choose Container Software
To select a fitting container solution, consider the following questions:
- How much management do you need for your containers? Do you have a small business and want to do much of the management on your own, or do you need almost everything automated?
- Which integrations are most important to you? Once you learn the other features you want alongside your container solution, such as security or storage, see which solutions offer them.
- Does the container software comply with the OCI’s standards? This may not be a must-have, but it’s good to look ahead so that the containers you use will be widely usable in the future.
Best Container Software Solutions
The following software selections include container engine, container orchestration, and container management solutions.
Designed to help developers and set containerization standards, Docker is a container engine software solution released under Apache License 2.0. Docker Desktop allows Mac, Windows, and Linux users to run containers on desktop computers. Desktop users have access to Snyk, a container security program that runs vulnerability scans on containers.
Docker Hub is a repository for container image searching and sharing. Users can push and pull, or upload and download, images and participate in both public and private repositories. Docker Hub is a useful resource for open source and community application development.
Swarm is a Docker feature for managing clusters of Docker engines. Swarm offers replicated or global services: in replicated services, the swarm manager gives tasks (known as replicas) to nodes; in global services, only one task is given per node that can handle it.
Docker also offers images, software that helps users build containers through code and details for running the container.
Originally designed by Google teams, Kubernetes is an open-source container orchestration platform released in 2013. Kubernetes integrates with other container management systems. It automatically rolls out updates to applications and configuration, but if that automatic rollout causes issues, it can also roll back the change. Kubernetes balances loads between pods (which hold multiple containers) and automatically places containers depending on resource requirements.
Kubernetes shows users node capacity and reliability — what the nodes are currently capable of running and their health status. It reveals whether a node is healthy enough to accept pods. Nodes have IP addresses, and pods can receive individual IP addresses as well. Kubernetes features self-healing capabilities: containers that don’t meet a user’s predetermined health standards die, containers that fail are restarted, and Kubernetes reschedules or replaces containers if a node carrying them dies.
Kubernetes is capable of mounting storage volumes, such as AWS, Portworx, Gluster, and fibre channel storage, onto its pods.
Amazon Elastic Container Service is a managed container orchestration service that integrates with other AWS programs. Built into ECS is Amazon Fargate, which scales and manages the infrastructure that users need for containers, servers, and their security. ECS Anywhere provides an Amazon control plane for users to manage their containers on premises; AWS Systems Manager integrates with Anywhere to secure those connections.
ECS uses Task Definitions to specify details about container needs, such as memory and CPU capability, through certain parameters like launch type and logging configuration. Users can update containers through uploading a new version of a task definition.
ECS supports Docker containers; customers can also use Docker Hub and third-party hosted Docker image repositories. ECS is also compatible with Windows containers.
Google Kubernetes Engine
Google Kubernetes Engine (GKE) is a container environment managed by Google, one of its cloud products. GKE has two modes: Standard, in which the user manages the nodes and can run custom workloads, and Autopilot, which is a managed infrastructure for users’ clusters.
GKE can be used alongside other Google services to build, test, and deploy new applications, as well as managing those applications. Users can bring workloads into GKE container environments using Migrate for Anthos, a solution for carrying applications from virtual machines to containers so that users don’t have to manually modernize them.
Users only pay for currently running pods in GKE, so that they aren’t charged extra for inactivity. GKE autoscales pods, working with available CPU and memory automatically, and can also autoscale clusters based on node pools.
Linux Containers focuses on system containers, which are similar to virtual machines but require less computing power and hardware simulation. It’s a set of solutions intended to create vendor neutrality for Linux containerization. Linux Containers backs the three following projects:
- LXC is an interface for Linux kernel containment features; it has an API for users to manage their containers. LXC is intended to be similar to standard Linux installations but without the extra kernel (which is what VMs require).
- LXD is a container manager for system containers. It offers pre-made images based on a REST API and uses security features like resource restrictions.
- LXCFS is a userspace file system that increases flexibility for running systemd-based containers. It’s free and released under the Apache 2.0 license.
Microsoft Azure offers a cloud-based managed Kubernetes container orchestration system for developing and deploying applications in containers. Azure has an arsenal of containerization options, but we’re focusing on Azure Kubernetes Service (AKS), for DevOps teams that need to build and scale applications. AKS gives users an Azure portal that shows them their Azure Kubernetes environment, including containers’ health status.
AKS provides DevOps teams with features like Visual Studio Code Kubernetes tools, a Microsoft extension for Kubernetes apps and clusters. AKS gives users access to Azure Active Directory, a security feature for authenticating user identities and building identity into app development.
AKS is a good choice for testing and upgrading Kubernetes applications. Users can perform continuous integration and continuous deployment for AKS clusters.