Container management is a process for automating the creation, deployment and scaling of containers. Container management facilitates the addition, replacement and organization of containers on a large scale.
A container is a lightweight package that bundles together a single app and its dependencies to make applications easier to develop, deploy and manage across complex IT environments. In contrast to virtual machines which package multiple apps and each have their own operating systems, containers run on one shared operating system. This allows them to load quickly, run across multiple clouds and platforms and move easily to different environments.
A container platform is software that creates, manages and secures containerized applications. Container management software allows for easier, faster networking and container orchestration. These platforms handle a number of containerized application processes, such as:
- Layered security
- Enterprise support
The most widely used container orchestration platform is Kubernetes, an extensible, open-source solution for managing containerized applications. Kubernetes provides a number of management tools, including:
- Service discovery and load balancing
- Rollout and rollback automation
- Storage orchestration
- Configuration management
Docker is another popular container software that can be used in conjunction with Kubernetes. One difference is that Docker runs on a single node, whereas Kubernetes is meant to manage clusters of nodes at scale.
Docker container lifecycle management involves the different phases of a container’s workflow: whether the container is running, paused, exited or retired. For a Docker container that is currently running, there are three options on the next stage in its lifecycle:
- Exit. Exiting a container is ideal for certain periods of company downtime, such as holidays.
- Pause. Pausing a container makes sense when you want to temporarily allocate your random-access memory (RAM) to one specific application.
- Kill. Killing a container is necessary during transitional stages, such as changing server requirements or migrating to a different server altogether.
For container management, Docker and Kubernetes are both widely used, accessible solutions.
Although a container platform is crucial to container management, picking one is only the first step. An organization must also choose an overall management system and strategy for adding additional management tools, taking into consideration its cloud architecture (Does the organization use public, private or hybrid cloud? Does it use multiple cloud providers? Which ones?) as well as other factors such as staff technical expertise and budget.
Simple container hosting (such as Docker) is sufficient for very basic private setups based in a single data center. However, the cloud architecture of most organizations demands an orchestrated approach, such as that provided by Kubernetes. Organizations can choose to use managed Kubernetes services from their cloud provider, or they can opt to tackle the implementation of Ku ontent/vmw bernetes themselves.
Containers need management so that systems can work more efficiently. Containers especially need a management system when the number of containers becomes too large for a single IT team to handle. With effective and integrated container management, IT admins can easily keep their environments more secure, while developers enjoy the flexibility and ease of containers to develop and deploy new apps and services.
There are a number of benefits to effective container management, including:
- Ease of setup. Container management includes storage, security tools, schedulers, monitoring systems and more, significantly reducing hosting setup complexities.
- Simplified administration. Good container management makes it easier for IT teams to administer and keep up with their containerized environments, as well as decreasing the time and resources needed for DevOps processes.
- Automation. Container management automates a number of processes, from load balancing to orchestration.
- Continuous health checks. Container management platforms like Kubernetes provide automatic health checks on apps, monitoring your environment for containers that have failed or stalled.
While container management provides a variety of benefits, it also comes with a number of challenges.
One of the top challenges of traditional container management is security. Container management and security are potentially at odds, since the container’s lightweight package makes it more vulnerable to hacking. Virtual machines inherently provide high security levels between machines, whereas container security is not as naturally strong since containers run on one shared operating system. In addition, dependencies such as API servers and monitoring tools make containers more vulnerable to attack. New technologies, however, are integrating containers within other IT systems to improve the security potential of containers.
In addition to security, other potential container management challenges include:
- Integration. Existing legacy infrastructures could need to be updated to provide the connectivity or API integration needed to support a container ecosystem.
- Learning curve. Containers are a relatively new technology, and IT teams need to be fully trained in container management in order to grasp how host server clusters impact containerized applications. Another option is to engage a service provider to deploy containers-as-a-service (CaaS).
- Storage. Since containers are designed to be operational only when they are needed, any information inside a container will be lost when that container shuts down. Retaining container-based information requires the adoption and use of container storage tools.
- Troubleshooting. Since containers are dynamically deployed to different hosts based on suitability at a given time, they often switch between hosts, which adds an additional step to troubleshooting. This means new container monitoring tools will be needed to be added to traditional server monitoring to track which container is allocated to which host.
In addition to container storage tools, there are a variety of tools an enterprise can leverage for container management.
While Kubernetes is the most widely-used container management software, there are many tools that collaborate with Kubernetes to streamline specific aspects of container management. A few examples of these include:
- D2iQ, which provides Mesos-based software for container management with hybrid cloud portability
- Docker’s swarm mode, a decentralized cluster management tool with load balancing and a declarative service model
Container monitoring tools are used to track which container is assigned to which host, along with useful metrics such as container performance and aspects of security. Container networking tools such as service mesh technology facilitate the relay of information between services within container clusters.