Red Hat build of MicroShift

MicroShift networking components and services

Understand networking components and services and their operation in MicroShift.

The microshift-networking RPM is a package that automatically pulls in any networking-related dependencies and systemd services to initialize networking, for example, the microshift-ovs-init systemd service.

NetworkManager

NetworkManager is required to set up the initial gateway bridge on the MicroShift node. The NetworkManager and NetworkManager-ovs RPM packages are installed as dependencies to the microshift-networking RPM package, which contains the necessary configuration files. NetworkManager in MicroShift uses the keyfile plugin and is restarted after installation of the microshift-networking RPM package.

microshift-ovs-init

The microshift-ovs-init.service is installed by the microshift-networking RPM package as a dependent systemd service to microshift.service. It is responsible for setting up the OVS gateway bridge.

OVN containers

Two OVN-Kubernetes daemon sets are rendered and applied by MicroShift.

ovnkube-master Includes the northd, nbdb, sbdb and ovnkube-master containers.
ovnkube-node The ovnkube-node includes the OVN-Controller container.

After MicroShift starts, the OVN-Kubernetes daemon sets are deployed in the openshift-ovn-kubernetes namespace.

Packaging

OVN-Kubernetes manifests and startup logic are built into MicroShift. The systemd services and configurations included in the microshift-networking RPM are:

/etc/NetworkManager/conf.d/microshift-nm.conf for NetworkManager.service
/etc/systemd/system/ovs-vswitchd.service.d/microshift-cpuaffinity.conf for ovs-vswitchd.service
/etc/systemd/system/ovsdb-server.service.d/microshift-cpuaffinity.conf for ovs-server.service
/usr/bin/configure-ovs-microshift.sh for microshift-ovs-init.service
/usr/bin/configure-ovs.sh for microshift-ovs-init.service
/etc/crio/crio.conf.d/microshift-ovn.conf for the CRI-O service