Kubernetes for Oban Auto Scaling

kubernetes.ex

defmodule Oban.Pro.Clouds.Kubernetes do
  @moduledoc false

  @behaviour Oban.Pro.Cloud

  @enforce_keys [:api_server, :bearer_token, :deployment, :namespace]
  defstruct @enforce_keys

  @impl Oban.Pro.Cloud
  def init(opts) do
    struct!(__MODULE__, opts)
  end

  @impl Oban.Pro.Cloud
  def scale(quantity, %__MODULE__{} = conf) do
    %{
      api_server: api_server,
      namespace: namespace,
      deployment: deployment,
      bearer_token: bearer_token
    } = conf

    url = "#{api_server}/apis/apps/v1/namespaces/#{namespace}/deployments/#{deployment}/scale"

    headers = [
      {"Content-Type", "application/strategic-merge-patch+json"},
      {"Accept", "application/json"},
      {"Authorization", "Bearer #{bearer_token}"}
    ]

    Req.patch!(url, json: %{"spec" => %{"replicas" => quantity}}, headers: headers)
  end
end