openshift/microshift

MicroShift

MicroShift is a project that optimizes OpenShift Kubernetes for small form factor and edge computing.

Edge devices deployed out in the field pose very different operational, environmental, and business challenges from those of cloud computing. These motivate different engineering trade-offs for Kubernetes at the far edge than for cloud or near-edge scenarios.

MicroShift design goals cater to this:

• make frugal use of system resources (CPU, memory, network, storage, etc.)
• tolerate severe networking constraints
• update securely, safely, speedily, and seamlessly (without disrupting workloads)
• build on and integrate cleanly with edge-optimized operating systems like RHEL for Edge
• provide a consistent development and management experience with standard OpenShift

These properties should also make MicroShift a great tool for other use cases such as Kubernetes applications development on resource-constrained systems, scale testing, and provisioning of lightweight Kubernetes control planes.

Architecture

MicroShift runs as a single systemd service that embeds a minimal OpenShift control plane and worker node. A single binary packages kube-apiserver, kube-controller-manager, kube-scheduler, kubelet, and OpenShift controllers as goroutines. Etcd runs as a separate process managed by the main binary.

Infrastructure services (DNS, ingress router, service CA, OVN-Kubernetes CNI, LVMS storage) are deployed onto the cluster after the control plane starts. Optional components (OLM, Gateway API, cert-manager, SR-IOV) are delivered as separate RPM packages and auto-discovered via the manifest path system.

MicroShift vendors OpenShift source code without modification. A given MicroShift release is built from the same content as the corresponding OpenShift release, following the same versioning scheme.

For technical details, see architecture. For design goals and principles, see design.

System Requirements

To run MicroShift, the minimum system requirements are:

• x86_64 or aarch64 CPU architecture
• Red Hat Enterprise Linux with Extended Update Support
• 2 CPU cores
• 2GB of RAM
• 2GB of free system root storage for MicroShift and its container images

The system requirements also include resources for the operating system unless explicitly mentioned otherwise.

Depending on user workload requirements, it may be necessary to add more resources i.e. CPU and RAM for better performance, disk space in a root partition for container images, an LVM group for container storage, etc.

Deploying MicroShift on Edge Devices

For production deployments, MicroShift can be run on bare metal hardware or hypervisors supported and certified for the Red Hat Enterprise Linux 9 operating system.

• Edge systems certified for Red Hat Enterprise Linux
• Hypervisors certified for Red Hat Enterprise Linux

User Documentation

To install, configure and run MicroShift, refer to the documentation in the user folder.

Contributing

See CONTRIBUTING.md for how to build, test, and submit changes to MicroShift.

For detailed contributor documentation including development environment setup, CI, and rebase procedures, see the contributor folder.

Community

Community build and CI sources managed at https://github.com/microshift-io/microshift and documentation sources are managed at https://github.com/redhat-et/microshift-documentation and published on https://microshift.io.

To get started with MicroShift, please refer to the Getting Started section of the MicroShift User Documentation.

For information about getting in touch with the MicroShift community, check our community page.