OpenAirInterface on Kubernetes

openair-k8s allows building high-quality OCI-compliant container images for the OpenAirInterface 4G/5G radio access (eNB/gNB) and core networks (EPC) and deploying these components on OpenShift or other enterprise-grade Kubernetes distributions.

Note: This is both experimental and work in progress.

Building OAI Container Images

Build Strategy

OpenAirInterface (OAI) components have many build-time dependencies, some of which need to be built from source. To ensure fast yet reproducible image builds, we create a common oai-build-base image that contains the build-time dependencies for all OAI components. Each component image is then built using the multistage build pattern: First build the OAI component using the oai-build-base image, then copy the component and its run-time dependencies into a fresh deployment image.

Images are built based on RHEL8 Universal Base Images (UBI) to yield small images with curated, high-quality content.

Prerequisites

As some of the required rpm packages for building OAI are not yet available via the UBI repos, images currently need to be built on a subscribed RHEL8 host, e.g. using the free RHEL8 developer subscriptions. On the RHEL8 build host:

sudo subscription-manager register
sudo subscription-manager attach
sudo yum install -y git podman nmap-ncat
git clone http://github.com/OPENAIRINTERFACE/openair-k8s
cd openair-k8s

Building

To build all OAI component images:

hack/build_images

To build selected OAI component images, e.g.:

hack/build_images oai-enb oai-ue

By default, OAI components are built using the stable git tag defined in the component's Dockerfile. To override this, specify an alternative git ref to build from, e.g.:

hack/build_images oai-enb:v1.0.0 oai-ue:master

Pushing to a Registry

To push the OAI images to an external registry, e.g. oai-hss to quay.io:

podman login quay.io
podman push oai-hss:1.0.1 quay.io/my_organisation/oai-hss:1.0.1

Cleaning

To delete all local OAI component images:

hack/clean_images

Add --help to these commands to see more options.

Checking Dockerfiles

To run a linter on all Dockerfiles:

hack/check_dockerfiles

Running OAI on Podman

Prerequisites

OAI containers will run with host networking (--net=host) and communicate via the loopback 127.0.1.1. To ensure the services' names can be properly resolved, add the following to /etc/hosts:

127.0.1.1	hss hss.openair4G.eur
127.0.1.1	mme mme.openair4G.eur
127.0.1.1	sgw sgw.openair4G.eur

Running

To test the OAI container images on your local machine, you can run them in podman like this:

hack/run_oai_on_podman

Cleaning

To delete the container instances created with above command, use:

hack/clean_oai_on_podman

Running OAI on Kubernetes

Prerequisites

Obviously, a running k8s cluster with kubectl set up correctly. This work is being developed and tested on OpenShift 4.2 (try it here). You also need kustomize installed:

curl -L https://github.com/kubernetes-sigs/kustomize/releases/download/v3.1.0/kustomize_3.1.0_linux_amd64 -o ~/bin/kustomize && chmod a+x ~/bin/kustomize

If necessary, generate new TLS certificates for the oai-hss and oai-mme services to match the namespace and cluster name you're deploying to, e.g.:

hack/generate_certs -p hss -d manifests/oai-hss/certs oai-hss.oai.svc.cluster.local
hack/generate_certs -p mme -d manifests/oai-mme/certs oai-mme.oai.svc.cluster.local

Running

If your user has permissions to create namespaces on the k8s cluster, you can simply run:

hack/run_oai_on_k8s

... which internally calls:

kustomize build manifests | kubectl apply -f -

If you need to use a namespace assigned to you, e.g. oai, modify manifests/kustomization.yaml to delete the 00_namespace.yaml resource and change the namespace field to your needs.

In order to run a single component, you have to point to the specific path where the manifests are located. For instnace, to run the MME on Kubernetes/OpenShift, please run:

kustomize build manifests/oai-mme | kubectl apply -f -

and to delete that component from running on the cluster, execute:

kustomize build manifests/oai-mme | kubectl delete -f -

Cleaning

To remove all resources from the 'oai' namespace plus delete the namespace itself, run:

hack/clean_oai_on_k8s