# Overview There are quite a few ways of running Tailscale inside a Kubernetes Cluster, some of the common ones are covered in this doc. ## Instructions ### Setup 1. (Optional) Create the following secret which will automate login.
You will need to get an [auth key](https://tailscale.com/kb/1085/auth-keys/) from [Tailscale Admin Console](https://login.tailscale.com/admin/authkeys).
If you don't provide the key, you can still authenticate using the url in the logs. ```yaml apiVersion: v1 kind: Secret metadata: name: tailscale-auth stringData: AUTH_KEY: tskey-... ``` 1. Build and push the container ```bash export IMAGE_TAG=tailscale-k8s:latest make push ``` 1. Tailscale (v1.16+) supports storing state inside a Kubernetes Secret. Configure RBAC to allow the Tailscale pod to read/write the `tailscale` secret. ```bash export SA_NAME=tailscale export KUBE_SECRET=tailscale-auth make rbac ``` ### Sample Sidecar Running as a sidecar allows you to directly expose a Kubernetes pod over Tailscale. This is particularly useful if you do not wish to expose a service on the public internet. This method allows bi-directional connectivity between the pod and other devices on the Tailnet. You can use [ACLs](https://tailscale.com/kb/1018/acls/) to control traffic flow. 1. Create and login to the sample nginx pod with a Tailscale sidecar ```bash make sidecar # If not using an auth key, authenticate by grabbing the Login URL here: kubectl logs nginx ts-sidecar ``` 1. Check if you can to connect to nginx over Tailscale: ```bash curl http://nginx ``` Or, if you have [MagicDNS](https://tailscale.com/kb/1081/magicdns/) disabled: ```bash curl "http://$(tailscale ip -4 nginx)" ``` #### Userspace Sidecar You can also run the sidecar in userspace mode. The obvious benefit is reducing the amount of permissions Tailscale needs to run, the downside is that for outbound connectivity from the pod to the Tailnet you would need to use either the [SOCKS proxy](https://tailscale.com/kb/1112/userspace-networking) or HTTP proxy. 1. Create and login to the sample nginx pod with a Tailscale sidecar ```bash make userspace-sidecar # If not using an auth key, authenticate by grabbing the Login URL here: kubectl logs nginx ts-sidecar ``` 1. Check if you can to connect to nginx over Tailscale: ```bash curl http://nginx ``` Or, if you have [MagicDNS](https://tailscale.com/kb/1081/magicdns/) disabled: ```bash curl "http://$(tailscale ip -4 nginx)" ``` ### Sample Proxy Running a Tailscale proxy allows you to provide inbound connectivity to a Kubernetes Service. 1. Provide the `ClusterIP` of the service you want to reach by either: **Creating a new deployment** ```bash kubectl create deployment nginx --image nginx kubectl expose deployment nginx --port 80 export DEST_IP="$(kubectl get svc nginx -o=jsonpath='{.spec.clusterIP}')" ``` **Using an existing service** ```bash export DEST_IP="$(kubectl get svc -o=jsonpath='{.spec.clusterIP}')" ``` 1. Deploy the proxy pod ```bash make proxy # If not using an auth key, authenticate by grabbing the Login URL here: kubectl logs proxy ``` 1. Check if you can to connect to nginx over Tailscale: ```bash curl http://proxy ``` Or, if you have [MagicDNS](https://tailscale.com/kb/1081/magicdns/) disabled: ```bash curl "http://$(tailscale ip -4 proxy)" ``` ### Subnet Router Running a Tailscale [subnet router](https://tailscale.com/kb/1019/subnets/) allows you to access the entire Kubernetes cluster network (assuming NetworkPolicies allow) over Tailscale. 1. Identify the Pod/Service CIDRs that cover your Kubernetes cluster. These will vary depending on [which CNI](https://kubernetes.io/docs/concepts/cluster-administration/networking/) you are using and on the Cloud Provider you are using. Add these to the `ROUTES` variable as comma-separated values. ```bash SERVICE_CIDR=10.20.0.0/16 POD_CIDR=10.42.0.0/15 export ROUTES=$SERVICE_CIDR,$POD_CIDR ``` 1. Deploy the subnet-router pod. ```bash make subnet-router # If not using an auth key, authenticate by grabbing the Login URL here: kubectl logs subnet-router ``` 1. In the [Tailscale admin console](https://login.tailscale.com/admin/machines), ensure that the routes for the subnet-router are enabled. 1. Make sure that any client you want to connect from has `--accept-routes` enabled. 1. Check if you can connect to a `ClusterIP` or a `PodIP` over Tailscale: ```bash # Get the Service IP INTERNAL_IP="$(kubectl get svc -o=jsonpath='{.spec.clusterIP}')" # or, the Pod IP # INTERNAL_IP="$(kubectl get po -o=jsonpath='{.status.podIP}')" INTERNAL_PORT=8080 curl http://$INTERNAL_IP:$INTERNAL_PORT ```