To deploy applications or make other changes through the {microshift-short} API with tools other than kustomize manifests, you must wait until the Greenboot health checks have finished. This ensures that your changes are not lost if Greenboot rolls your rpm-ostree system back to an earlier state.
The greenboot-healthcheck service runs one time and then exits. After Greenboot has exited and the system is in a healthy state, you can proceed with configuration changes and deployments.