--- title: Charmhub | Deploy Multus using Charmhub - The Open Operator Collection description: Deploy the latest version of Multus on any cloud. Multus CNI for Kubernetes url: https://charmhub.io/multus --- # Multus [Canonical Kubernetes](https://charmhub.io/publisher/containers "View all packages from Canonical Kubernetes") * [Canonical Kubernetes](https://charmhub.io/publisher/containers "View all packages from Canonical Kubernetes") Platform: 22.04 20.04 stable e57c10b ``` juju deploy multus ``` [Learn to deploy on juju >](https://juju.is/docs/juju/manage-applications) --- #### Relevant links * [Contact](mailto:George Kraft ) --- #### Contacts ##### Maintainers + [George Kraft](mailto:george.kraft@canonical.com) + [Mateo Florido](mailto:mateo.florido@canonical.com) --- Share your thoughts on this charm with the community on discourse. [Join the discussion](https://discourse.charmhub.io/) [Multus][multus] is a CNI plugin for Kubernetes which enables attaching multiple network interfaces to pods. Multus support for **Charmed Kubernetes** is provided by the Multus charm, which must be deployed into a Kubernetes model in Juju. ## Requirements ### Juju 2.8.0 The Multus charm requires Juju 2.8.0 or newer. ### CNI providers Multus is not a replacement for other CNI providers. Your **Charmed Kubernetes** deployment must include at least one of the base CNI providers documented in the [CNI overview][cni-overview] page. ### Persistent volume support In order to deploy Multus, you will need a Kubernetes model in Juju, which requires persistent volume support to be enabled in your **Charmed Kubernetes** cluster. If your cluster includes any of the cloud integrator charms, then you should have persistent volume support already. Otherwise, you can read the [Storage][storage] documentation page to learn how to enable persistent volume support by adding Ceph to your cluster. ### Creating a Kubernetes model in Juju To deploy the Multus charm, you will first need a Kubernetes model in Juju. Make sure your local kubeconfig is pointing to the correct Kubernetes cluster: ``` juju scp kubernetes-control-plane/0:config ~/.kube/config ``` Next, add your Kubernetes as a cloud to your Juju controller: ``` juju add-k8s my-k8s-cloud --controller $(juju switch | cut -d: -f1) ``` And create a new Kubernetes model: ``` juju add-model my-k8s-model my-k8s-cloud ``` ## Deploying Multus Once all of the requirements have been met, you can deploy Multus into a Kubernetes model by running: ``` juju deploy multus ``` ## Configuring the Default CNI Multus delegates to a single CNI network by default. If you have multiple CNI subordinates in your cluster then you can use the default-cni config on kubernetes-control-plane to set the default: ``` juju config kubernetes-control-plane default-cni=flannel ``` Multus will use this as the default network as well. ## Example: Pod with multiple Flannel interfaces If you have Flannel in your cluster, then you can use it to attach additional network interfaces to your pods. In this example, we’ll create an Ubuntu pod with 2 extra Flannel interfaces, in addition to the default one. Create a NetworkAttachmentDefinition for Flannel: ``` apiVersion: "k8s.cni.cncf.io/v1" kind: NetworkAttachmentDefinition metadata: name: flannel spec: config: | { "cniVersion": "0.3.1", "plugins": [ { "type": "flannel", "delegate": { "hairpinMode": true, "isDefaultGateway": true } }, { "type": "portmap", "capabilities": {"portMappings": true}, "snat": true } ] } ``` Create a Pod with the `k8s.v1.cni.cncf.io/networks` annotation: ``` apiVersion: v1 kind: Pod metadata: name: ubuntu annotations: k8s.v1.cni.cncf.io/networks: flannel, flannel spec: containers: - name: ubuntu image: ubuntu command: ['sleep', '3600'] ``` That’s it. After the pod comes up, you can exec into the pod and confirm that it has multiple network interfaces with IP addresses belonging to the Flannel network: ``` $ kubectl exec -it ubuntu bash root@ubuntu:/# apt update && apt install -y net-tools ... root@ubuntu:/# ifconfig eth0: flags=4163 mtu 8951 inet 10.1.34.6 netmask 255.255.255.0 broadcast 0.0.0.0 inet6 fe80::c001:5aff:feb8:fefd prefixlen 64 scopeid 0x20 ether c2:01:5a:b8:fe:fd txqueuelen 0 (Ethernet) RX packets 5447 bytes 18185162 (18.1 MB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 4666 bytes 356784 (356.7 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1000 (Local Loopback) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 net1: flags=4163 mtu 8951 inet 10.1.34.3 netmask 255.255.255.0 broadcast 0.0.0.0 inet6 fe80::78fe:9ff:fe80:ec57 prefixlen 64 scopeid 0x20 ether 7a:fe:09:80:ec:57 txqueuelen 0 (Ethernet) RX packets 42 bytes 3220 (3.2 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 11 bytes 838 (838.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 net2: flags=4163 mtu 8951 inet 10.1.34.4 netmask 255.255.255.0 broadcast 0.0.0.0 inet6 fe80::acad:f6ff:feaa:416f prefixlen 64 scopeid 0x20 ether ae:ad:f6:aa:41:6f txqueuelen 0 (Ethernet) RX packets 40 bytes 3088 (3.0 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 11 bytes 838 (838.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ``` In this case, `eth0` is the default interface that gets attached to all pods, while `net1` and `net2` are the additional interfaces that Multus attached to the pod based on the pod’s `k8s.v1.cni.cncf.io/networks` annotation. For additional examples of how you can use Multus, please refer to the official Multus documentation here: [Create network attachment definition][multus-examples]. ## Troubleshooting If there is an issue with Multus, it can be useful to inspect the Juju logs. To see a complete set of logs for Multus: ``` juju debug-log --replay --include=multus ``` For additional troubleshooting pointers, please see the [dedicated troubleshooting page][troubleshooting]. --- [Help improve this document in the forum](https://discourse.charmhub.io/t/multus-docs-index/6319) ([guidelines](https://discourse.charmhub.io/t/how-to-write-docs-our-documentation-guidelines-for-contributors/1245)). Last updated 3 years ago.