# The Kubernetes dashboard - Kubernetes resources can also be viewed with a web dashboard - Dashboard users need to authenticate (typically with a token) - The dashboard should be exposed over HTTPS (to prevent interception of the aforementioned token) - Ideally, this requires obtaining a proper TLS certificate (for instance, with Let's Encrypt) --- ## Three ways to install the dashboard - Our `k8s` directory has no less than three manifests! - `dashboard-recommended.yaml` (purely internal dashboard; user must be created manually) - `dashboard-with-token.yaml` (dashboard exposed with NodePort; creates an admin user for us) - `dashboard-insecure.yaml` aka *YOLO* (dashboard exposed over HTTP; gives root access to anonymous users) --- ## `dashboard-insecure.yaml` - This will allow anyone to deploy anything on your cluster (without any authentication whatsoever) - **Do not** use this, except maybe on a local cluster (or a cluster that you will destroy a few minutes later) - On "normal" clusters, use `dashboard-with-token.yaml` instead! --- ## What's in the manifest? - The dashboard itself - An HTTP/HTTPS unwrapper (using `socat`) - The guest/admin account .lab[ - Create all the dashboard resources, with the following command: ```bash kubectl apply -f ~/container.training/k8s/dashboard-insecure.yaml ``` ] --- ## Connecting to the dashboard .lab[ - Check which port the dashboard is on: ```bash kubectl get svc dashboard ``` ] You'll want the `3xxxx` port. .lab[ - Connect to http://oneofournodes:3xxxx/ ] The dashboard will then ask you which authentication you want to use. --- ## Dashboard authentication - We have three authentication options at this point: - token (associated with a role that has appropriate permissions) - kubeconfig (e.g. using the `~/.kube/config` file from `node1`) - "skip" (use the dashboard "service account") - Let's use "skip": we're logged in! -- .warning[Remember, we just added a backdoor to our Kubernetes cluster!] --- ## Closing the backdoor - Seriously, don't leave that thing running! .lab[ - Remove what we just created: ```bash kubectl delete -f ~/container.training/k8s/dashboard-insecure.yaml ``` ] --- ## The risks - The steps that we just showed you are *for educational purposes only!* - If you do that on your production cluster, people [can and will abuse it](https://redlock.io/blog/cryptojacking-tesla) - For an in-depth discussion about securing the dashboard,
check [this excellent post on Heptio's blog](https://blog.heptio.com/on-securing-the-kubernetes-dashboard-16b09b1b7aca) --- ## `dashboard-with-token.yaml` - This is a less risky way to deploy the dashboard - It's not completely secure, either: - we're using a self-signed certificate - this is subject to eavesdropping attacks - Using `kubectl port-forward` or `kubectl proxy` is even better --- ## What's in the manifest? - The dashboard itself (but exposed with a `NodePort`) - A ServiceAccount with `cluster-admin` privileges (named `kubernetes-dashboard:cluster-admin`) .lab[ - Create all the dashboard resources, with the following command: ```bash kubectl apply -f ~/container.training/k8s/dashboard-with-token.yaml ``` ] --- ## Obtaining the token - The manifest creates a ServiceAccount - Kubernetes will automatically generate a token for that ServiceAccount .lab[ - Display the token: ```bash kubectl --namespace=kubernetes-dashboard \ describe secret cluster-admin-token ``` ] The token should start with `eyJ...` (it's a JSON Web Token). Note that the secret name will actually be `cluster-admin-token-xxxxx`.
(But `kubectl` prefix matches are great!) --- ## Connecting to the dashboard .lab[ - Check which port the dashboard is on: ```bash kubectl get svc --namespace=kubernetes-dashboard ``` ] You'll want the `3xxxx` port. .lab[ - Connect to http://oneofournodes:3xxxx/ ] The dashboard will then ask you which authentication you want to use. --- ## Dashboard authentication - Select "token" authentication - Copy paste the token (starting with `eyJ...`) obtained earlier - We're logged in! --- ## Other dashboards - [Kube Web View](https://codeberg.org/hjacobs/kube-web-view) - read-only dashboard - optimized for "troubleshooting and incident response" - see [vision and goals](https://kube-web-view.readthedocs.io/en/latest/vision.html#vision) for details - [Kube Ops View](https://codeberg.org/hjacobs/kube-ops-view) - "provides a common operational picture for multiple Kubernetes clusters" --- # Security implications of `kubectl apply` - When we do `kubectl apply -f `, we create arbitrary resources - Resources can be evil; imagine a `deployment` that ... -- - starts bitcoin miners on the whole cluster -- - hides in a non-default namespace -- - bind-mounts our nodes' filesystem -- - inserts SSH keys in the root account (on the node) -- - encrypts our data and ransoms it -- - ☠️☠️☠️ --- ## `kubectl apply` is the new `curl | sh` - `curl | sh` is convenient - It's safe if you use HTTPS URLs from trusted sources -- - `kubectl apply -f` is convenient - It's safe if you use HTTPS URLs from trusted sources - Example: the official setup instructions for most pod networks -- - It introduces new failure modes (for instance, if you try to apply YAML from a link that's no longer valid) ??? :EN:- The Kubernetes dashboard :FR:- Le *dashboard* Kubernetes