Running on Kubernetes#

Note

Kubernetes support is under active development. Please share your feedback or directly reach out to the development team for feature requests and more.

SkyPilot tasks can be run on your private on-prem or cloud Kubernetes clusters. The Kubernetes cluster gets added to the list of “clouds” in SkyPilot and SkyPilot tasks can be submitted to your Kubernetes cluster just like any other cloud provider.

Benefits of using SkyPilot to run jobs on your Kubernetes cluster:

Get SkyPilot features (setup management, job execution, queuing, logging, SSH access) on your Kubernetes resources
Replace complex Kubernetes manifests with simple SkyPilot tasks
Seamlessly “burst” jobs to the cloud if your Kubernetes cluster is congested
Retain observability and control over your cluster with your existing Kubernetes tools

Supported Kubernetes deployments:

Hosted Kubernetes services (EKS, GKE)
On-prem clusters (Kubeadm, Rancher)
Local development clusters (KinD, minikube)

Kubernetes Cluster Requirements#

To connect and use a Kubernetes cluster, SkyPilot needs:

An existing Kubernetes cluster running Kubernetes v1.20 or later.
A Kubeconfig file containing access credentials and namespace to be used.

In a typical workflow:

A cluster administrator sets up a Kubernetes cluster. Detailed admin guides for different deployment environments (Amazon EKS, Google GKE, On-Prem and local debugging) are included in the Kubernetes cluster setup guide.
Users who want to run SkyPilot tasks on this cluster are issued Kubeconfig files containing their credentials (kube-context). SkyPilot reads this Kubeconfig file to communicate with the cluster.

Submitting SkyPilot tasks to Kubernetes Clusters#

Once your cluster administrator has setup a Kubernetes cluster and provided you with a kubeconfig file:

Make sure kubectl, socat and nc (netcat) are installed on your local machine.

$ # MacOS
$ brew install kubectl socat netcat

$ # Linux (may have socat already installed)
$ sudo apt-get install kubectl socat netcat

Place your kubeconfig file at ~/.kube/config.
```
$ mkdir -p ~/.kube
$ cp /path/to/kubeconfig ~/.kube/config
```
You can verify your credentials are setup correctly by running kubectl get pods.
Run sky check and verify that Kubernetes is enabled in SkyPilot.
```
$ sky check

Checking credentials to enable clouds for SkyPilot.
...
Kubernetes: enabled
...
```
Note

sky check will also check if GPU support is available on your cluster. If GPU support is not available, it will show the reason. To setup GPU support on the cluster, refer to the Kubernetes cluster setup guide.

You can now run any SkyPilot task on your Kubernetes cluster.

$ sky launch --cpus 2+ task.yaml
== Optimizer ==
Target: minimizing cost
Estimated cost: $0.0 / hour

Considered resources (1 node):
---------------------------------------------------------------------------------------------------
 CLOUD        INSTANCE          vCPUs   Mem(GB)   ACCELERATORS   REGION/ZONE   COST ($)   CHOSEN
---------------------------------------------------------------------------------------------------
 Kubernetes   2CPU--2GB         2       2         -              kubernetes    0.00          ✔
 AWS          m6i.large         2       8         -              us-east-1     0.10
 Azure        Standard_D2s_v5   2       8         -              eastus        0.10
 GCP          n2-standard-2     2       8         -              us-central1   0.10
 IBM          bx2-8x32          8       32        -              us-east       0.38
 Lambda       gpu_1x_a10        30      200       A10:1          us-east-1     0.60
---------------------------------------------------------------------------------------------------.

Note

SkyPilot will use the cluster and namespace set in the current-context in the kubeconfig file. To manage your current-context:

$ # See current context
$ kubectl config current-context

$ # Switch current-context
$ kubectl config use-context mycontext

$ # Set a specific namespace to be used in the current-context
$ kubectl config set-context --current --namespace=mynamespace

Using Custom Images#

By default, we use and maintain a SkyPilot container image that has conda and a few other basic tools installed.

To use your own image, add image_id: docker:<your image tag> to the resources section of your task YAML.

resources:
  image_id: docker:myrepo/myimage:latest
...

Your image must satisfy the following requirements:

Image must be debian-based and must have the apt package manager installed.
The default user in the image must have root privileges or passwordless sudo access.

Note

If your cluster runs on non-x86_64 architecture (e.g., Apple Silicon), your image must be built natively for that architecture. Otherwise, your job may get stuck at Start streaming logs .... See GitHub issue for more.

Using Images from Private Repositories#

To use images from private repositories (e.g., Private DockerHub, Amazon ECR, Google Container Registry), create a secret in your Kubernetes cluster and edit your ~/.sky/config.yaml to specify the secret like so:

kubernetes:
  pod_config:
    spec:
      imagePullSecrets:
        - name: your-secret-here

Tip

If you use Amazon ECR, your secret credentials may expire every 12 hours. Consider using k8s-ecr-login-renew to automatically refresh your secrets.

Opening Ports#

Opening ports on SkyPilot clusters running on Kubernetes is supported through two modes:

LoadBalancer services (default)
Nginx IngressController

One of these modes must be supported and configured on your cluster. Refer to the setting up ports on Kubernetes guide on how to do this.

Tip

On Google GKE, Amazon EKS or other cloud-hosted Kubernetes services, the default LoadBalancer services mode is supported out of the box and no additional configuration is needed.

Once your cluster is configured, launch a task which exposes services on a port by adding ports to the resources section of your task YAML.

# task.yaml
resources:
  ports: 8888

run: |
  python -m http.server 8888

After launching the cluster with sky launch -c myclus task.yaml, you can get the URL to access the port using sky status --endpoints myclus.

# List all ports exposed by the cluster
$ sky status --endpoints myclus
8888: 34.173.13.241:8888

# curl a specific port's endpoint
$ curl $(sky status --endpoint 8888 myclus)
...

Tip

To learn more about opening ports in SkyPilot tasks, see Opening Ports.

FAQs#

Are autoscaling Kubernetes clusters supported?

To run on an autoscaling cluster, you may need to adjust the resource provisioning timeout (Kubernetes.TIMEOUT in clouds/kubernetes.py) to a large value to give enough time for the cluster to autoscale. We are working on a better interface to adjust this timeout - stay tuned!
Can SkyPilot provision a Kubernetes cluster for me? Will SkyPilot add more nodes to my Kubernetes clusters?

The goal of Kubernetes support is to run SkyPilot tasks on an existing Kubernetes cluster. It does not provision any new Kubernetes clusters or add new nodes to an existing Kubernetes cluster.
I have multiple users in my organization who share the same Kubernetes cluster. How do I provide isolation for their SkyPilot workloads?

For isolation, you can create separate Kubernetes namespaces and set them in the kubeconfig distributed to users. SkyPilot will use the namespace set in the kubeconfig for running all tasks.

How can I specify custom configuration for the pods created by SkyPilot?

You can override the pod configuration used by SkyPilot by setting the pod_config key in ~/.sky/config.yaml. The value of pod_config should be a dictionary that follows the Kubernetes Pod API.

For example, to set custom environment variables and attach a volume on your pods, you can add the following to your ~/.sky/config.yaml file:

kubernetes:
  pod_config:
    spec:
      containers:
        - env:
          - name: MY_ENV_VAR
            value: MY_ENV_VALUE
          volumeMounts:       # Custom volume mounts for the pod
            - mountPath: /foo
              name: example-volume
      volumes:
        - name: example-volume
          hostPath:
            path: /tmp
            type: Directory

For more details refer to Advanced Configurations.

Features and Roadmap#

Kubernetes support is under active development. Some features are in progress and will be released soon:

CPU and GPU Tasks - ✅ Available
Auto-down - ✅ Available
Storage mounting - ✅ Available on x86_64 clusters
Multi-node tasks - ✅ Available
Custom images - ✅ Available
Opening ports and exposing services - ✅ Available
Multiple Kubernetes Clusters - 🚧 In progress