AWS EBS CSI

This pack deploys two jobs that run the AWS EBS CSI plugin. The node plugin tasks will be run as a system job, and the controller tasks will be run as a service job.

Client Requirements

This pack can only be run on Nomad clients that have enabled volumes and privileged mode for the Docker task driver. In addition, clients will need to be deployed in every availability zone where you intend to create volumes.

Variables

• job_name (string "democratic_csi") - The prefix to use as the job name for the plugins. For exmaple, if job_name = "democratic_csi", the plugin job will be named democratic_csi_controller.
• datacenters (list(string) ["dc1"]) - A list of datacenters in the region which are eligible for task placement.
• region (string "global") - The region where the job should be placed.
• plugin_id (string "org.democratic-csi.nfs") - The ID to register in Nomad for the plugin.
• plugin_namespace (string "default") - The namespace for the plugin job.
• plugin_image (string "public.ecr.aws/ebs-csi-driver/aws-ebs-csi-driver:v1.5.1") - The container image for the plugin.
• plugin_csi_spec_version (string "1.5.0") - The CSI spec version that democratic-csi will comply with.
• plugin_log_level (string "debug") - The log level for the plugin.
• availability_zones (list(string) ["us-east-1b"]) - AWS availability zones for the node plugins and example volume output.
• controller_count (number 2) - The number of controller instances to be deployed (at least 2 recommended).
• volume_id (string "myvolume") - ID for the example volume spec to output.
• volume_namespace (string "default") - Namespace for the example volume spec to output.
• volume_min_capacity (string "10GiB") - Minimum capacity for the example volume spec to output.
• volume_max_capacity (string "30GiB") - Maximum capacity for the example volume spec to output.
• volume_type (string "gp2") - AWS EBS volume type.

constraints List of Objects

Nomad job specification constraints allow restricting the set of eligible nodes on which the tasks will run. This pack automatically configures the following required constraints:

• Plugin tasks will run on Linux hosts only
• The node plugin tasks will run on hosts with the Docker driver's volumes enabled and allow_privileged set to true.
• The controller plugin tasks will be deployed on distinct hosts.

You can set additional constraints with the constraints variable, which takes a list of objects with the following fields:

• attribute (string) - Specifies the name or reference of the attribute to examine for the constraint.
• operator (string) - Specifies the comparison operator. The ordering is compared lexically.
• value (string) - Specifies the value to compare the attribute against using the specified operation.

Below is also an example of how to pass constraints to the CLI with with the -var argument.

nomad-pack run -var 'constraints=[{"attribute":"$${meta.my_custom_value}","operator":">","value":"3"}]' packs/aws_ebs_csi

resources Object

• cpu (number 500) - Specifies the CPU required to run this task in MHz.
• memory (number 256) - Specifies the memory required in MB.

Volume creation

This pack outputs an example volume specification based on the plugin variables.

volume.hcl

type         = "csi"
id           = "myvolume"
namespace    = "default"
plugin_id    = "ebs.csi.aws.com"

# this is used as the AWS EBS volume's CSIVolumeName tag, and
# must be unique per region
name         = "eecede36-6de0-4de1-9a06-6d201c29e2a2"

capacity_min = "10GiB"
capacity_max = "30GiB"

capability {
  access_mode     = "single-node-writer"
  attachment_mode = "file-system"
}

capability {
  access_mode     = "single-node-writer"
  attachment_mode = "block-device"
}

parameters {
  type = "gp2"
}

topology_request {
  required {
    topology {
      segments {

        "topology.ebs.csi.aws.com/zone" = "us-east-1a"
        "topology.ebs.csi.aws.com/zone" = "us-east-1b"
      }
    }
  }
}

Create this volume with the following command:

nomad volume create volume.hcl