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Containers have gained serious attention as an attractive platform for next-generation application packaging and deployment. Containers promise numerous benefits, including resource efficiency, fast spin-up and high scalability. Containers also require an operating environment that is specifically tailored to support container technology, and this can pose concerns for existing hypervisors. VMware has embraced containers through its delivery of VMware container support in vSphere Integrated Containers.
VIC is a feature of VMware vSphere versions 6.0 and later that allows administrators to create containers and deploy container images alongside traditional VMs without the need to install additional software or framework to support container technology. VIC provides VMware container support through two general deployment models: virtual container hosts and Docker container hosts.
Virtual container hosts create containers as VMs
With virtual container hosts, VIC uses the existing vSphere mechanisms to create containers as individual -- albeit highly optimized -- VMs. Virtual container hosts provisioned by the VIC engine possess the principal characteristics expected of containers. For example, a virtual container host will boot from an ISO file using a Photon Linux guest as the common kernel, which requires OS image layers -- added to the containers -- in order to function. The containers are ephemeral with temporary storage or optional access to persistent storage volume. The containers can function across numerous different network topologies configured through software-defined data center technologies, including VMware NSX. A virtual container host appears in vSphere as a vApp entity.
Since virtual container hosts are essentially VMs, a VMware container can take advantage of all of the features and functionalities available to a traditional vSphere VM, including isolation, security, availability and performance capabilities, such as VMware High Availability, migration and Distributed Resource Scheduler. According to VMware, such container deployments work best for well-proven, production-ready workloads.
Docker container hosts build images
VIC provides VMware container support through Docker container hosts as an alternative option for deployment that allows organizations to provision and manage Docker containers using versions 1.25 or later of the Docker API under vSphere. Docker containers can act as a sandbox for software developers, can be deployed in a production environment as a build server or can be combined into a cluster with Docker Swarm. VIC continues to present the Docker API to developers and administrators. The Docker container host is available to create and build images that will function in virtual container hosts because the VIC engine can run, but not build, images.
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