Kubernetes is the leading technology for the deployment and orchestration of containerized workloads in cloud-native environments.
Seqera Platform streamlines the deployment of Nextflow pipelines into Kubernetes, both for cloud-based and on-prem clusters.
To prepare your Kubernetes cluster for the deployment of Nextflow pipelines using Seqera, this guide assumes that you've already created the cluster and that you have administrative privileges.
Prepare your Kubernetes cluster for Seqera Platform
Verify the connection to your Kubernetes cluster:
Create the Seqera launcher:
kubectl apply -f https://docs.seqera.io/platform/v23-2-0/_templates/k8s/tower-launcher.yml
This command creates a service account called
tower-launcher-saand the associated role bindings, all contained in a namespace called
tower-nf. Seqera uses the service account to launch Nextflow pipelines. Use this service account name when setting up the compute environment for this Kubernetes cluster in Seqera.
Create persistent storage. Seqera requires a
ReadWriteManypersistent volume claim (PVC) mounted to all nodes where workflow pods will be dispatched.
You can use any storage solution that supports the
ReadWriteManyaccess mode. The setup of this storage is beyond the scope of these instructions — the right solution for you will depend on what is available for your infrastructure or cloud vendor (NFS, GlusterFS, CephFS, Amazon FSx). Ask your cluster administrator for more information.
Apply the appropriate PVC configuration to your cluster:
kubectl apply -f <PVC_YAML_FILE>.
Seqera compute environment#
After you've prepared your Kubernetes cluster for Seqera integration, create a compute environment:
Create a Seqera Kubernetes compute environment
In a workspace, select Compute environments > New environment.
Enter a descriptive name for this environment, e.g., K8s cluster.
Select Kubernetes as the target platform.
From the Credentials drop-down, select existing Kubernetes credentials, or select + to add new credentials. If you choose to use existing credentials, skip to step 7.
You can create multiple credentials in your Seqera workspace. See Credentials.
Enter a name, e.g., K8s Credentials.
Enter the Service account token.
Obtain the token with the following command:
SECRET=$(kubectl get secrets | grep <SERVICE-ACCOUNT-NAME> | cut -f1 -d ' ') kubectl describe secret $SECRET | grep -E '^token' | cut -f2 -d':' | tr -d '\t'
<SERVICE-ACCOUNT-NAME>with the name of the service account created in the cluster preparation instructions (default:
Enter the Control plane URL.
Obtain the control plane URL with the following command:
It can also be found in your
~/.kube/configfile under the
serverfield corresponding to your cluster.
Specify the SSL certificate to authenticate your connection.
Find the certificate data in your
~/.kube/configfile. It is the
certificate-authority-datafield corresponding to your cluster.
Specify the Namespace created in the cluster preparation instructions, which is tower-nf by default.
Specify the Head service account created in the cluster preparation instructions, which is tower-launcher-sa by default.
Specify the Storage claim created in the cluster preparation instructions, which serves as a scratch filesystem for Nextflow pipelines. The storage claim is called tower-scratch in each of the provided examples.
Apply Resource labels to the cloud resources consumed by this compute environment. Workspace default resource labels are prefilled.
Expand Staging options to include optional pre- or post-run Bash scripts that execute before or after the Nextflow pipeline execution in your environment.
You can use the Environment variables option to specify custom environment variables for the Head job and/or Compute jobs.
Configure any advanced options described below, as needed.
Select Create to finalize the compute environment setup.
See Launch pipelines to start executing workflows in your Kubernetes compute environment.
Seqera Platform compute environments for Kubernetes include advanced options for storage and work directory paths, resource allocation, and pod customization.
Seqera Kubernetes advanced options
The Storage mount path is the file system path where the Storage claim is mounted (default:
The Work directory is the file system path used as a working directory by Nextflow pipelines. It must be the storage mount path (default) or a subdirectory of it.
The Compute service account is the service account used by Nextflow to submit tasks (default: the
defaultaccount in the given namespace).
The Pod cleanup policy determines when to delete terminated pods.
Use Custom head pod specs to provide custom options for the Nextflow workflow pod (
affinity, etc). For example:
1 2 3
spec: nodeSelector: disktype: ssd
Use Custom service pod specs to provide custom options for the compute environment pod. See above for an example.
Use Head Job CPUs and Head Job memory to specify the hardware resources allocated to the Nextflow workflow pod.