free5GC Helm Installation

Prerequirements

Microk8s Installation

Install packages

sudo snap install microk8s --classic --channel=1.29/stable

To work with local kubectl

sudo snap install kubectl --classic
sudo snap install helm --classic
microk8s config > ~/.kube/config
su - $USER

Verify the Installation
```
microk8s status --wait-ready
```
Create namespace for free5gc
```
kubectl create ns free5gc
```

Network configuration

Reference: Toward5Gs -- Network Configuration
This Helm chart requires two network interfaces: eth0 and eth1
- Both of them should have the ability to connect to the Internet
- By default, one of them (eth1) will be the N6 network interface
In Summary, the value.yaml in each configuration should be set up correctly
- Suppose we have two NW interfaces:
  1. eth0: 172.19.244.39/20
  2. eth1: 192.168.50.43/24
- We take eth1 as the interface connected to DN, the following values should be changed:
  1. global.n6network.subnetIP, global.n6network.gatewayIP
  2. free5gc-upf.n6if.ipAddress
  3. For changing the interface, these values should be modified: global.n2network.masterIf, global.n3network.masterIf, global.n4network.masterIf, global.n6network.masterIf
- free5gc-helm/charts/free5gc/value.yaml
```
global:
  n6network:
    enabled: true
    name: n6network
    type: ipvlan
    masterIf: eth1
    subnetIP: 192.168.50.0
    cidr: 24
    gatewayIP: 192.168.50.1
    excludeIP: 10.100.100.254
```
- free5gc-helm/charts/free5gc/charts/free5gc-upf/values.yaml
```
upf:    
    n6if:  # DN
        ipAddress: 192.168.50.66
```
  - When choosing "ULCL" architecture for the user plane, n6if configuration in upf1, upf2, upfb should also be changed to the DN interface
- These values could be setup by using helm install --set, see helm chart installation

CNI Plugin Configuration

Starting from version 1.19, MicroK8s clusters use the Calico CNI by default (ref).
- To enable IP forwarding on UPF, Calico CNI needs some necessary configurations.
- Some CNI plugin, like Flannel, kube-ovn, allow this funtionality by default

Setup Calico CNI for IP Forwarding

/var/snap/microk8s/current/args/cni-network/cni.yaml

kind: ConfigMap
data:
    cni_network_config: |-
        {
            # Append IP forwarding settings
            "container_settings": {
                "allow_ip_forwarding": true
            }
        }

Apply settings

kubectl apply -f /var/snap/microk8s/current/args/cni-network/cni.yaml

Otherwise, Use kube-ovn CNI plugin
```
sudo microk8s enable kube-ovn --force
```
- Official doc

multus-cni plugin

Enables attaching multiple network interfaces to pods
- Github link

MicroK8s multus addons

microk8s enable community
microk8s enable multus

Reference Multus Guide
1. Multus - Create Network Definitions
2. Multus - Tell pods to use those networks via annotations

Installation

Create Persistent Volumn

Use kubectl apply to declarative create persistent volume

kubectl apply -f persistent-vol-for-mongodb.yaml

persistent-vol-for-mongodb.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: example-local-pv9
  labels:
    project: free5gc
spec:
  capacity:
    storage: 8Gi
  accessModes:
  - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  local:
    path: </path/to/storage>
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - <work-node-name>

directory on /path/to/storage should be created previously

Check persistent volume
```
kubectl get persistentvolume
```

Helm Chart

Enter the directory: free5gc-helm/charts/

free5GC

microk8s helm install -n free5gc free5gc-helm ./free5gc/

Install with customized interface settings

helm install -n free5gc free5gc-helm ./free5gc/ \
--set global.n6network.subnetIP="192.168.50.0" \
--set global.n6network.gatewayIP="192.168.50.1" \
--set free5gc-upf.upf.n6if.ipAddress="192.168.50.66"

UERANSIM

microk8s helm install -n free5gc ueransim ./ueransim/

Verification
- List installed charts
```
helm ls -A
```
- Check services, pods, repicaets, and deployments
```
kubectl get all -n free5gc 
```

Check IP forwarding is avalible in upf

kubectl exec -it -n free5gc deployment/free5gc-helm-free5gc-upf-upf \
-- cat /proc/sys/net/ipv4/ip_forward

This output should be 1

Result

Test

Add subscribors via webui

Port forwarding

kubectl port-forward svc/webui-service 5000:5000  --address 0.0.0.0

access <externel_ip>:5000

Ping externel network with tunnel

kubectl exec -it -n free5gc deployment/ueransim-ue -- ping -I uesimtun0 8.8.8.8