Trying to work through the Jepsen tutorial but in dummy mode

dumbo.clj

(ns jepsen.dumbo
  (:require [clojure.tools.logging :refer :all]
            [clojure.string :as str]
            [jepsen
             [cli :as cli]
             [control :as c]
             [db :as db]
             [tests :as tests]]
            [jepsen.control.util :as cu]
            [jepsen.os :as os]))

(def dir "/opt/etcd")


(defn dumbo-db
  "Dumbo DB for a particular version."
  [version]
  (reify db/DB
    (setup! [_ test node]
      (info node "installing dumbo" version)
      (c/su
       (let [url (str "https://storage.googleapis.com/etcd/" version
                      "/etcd-" version "-linux-amd64.tar.gz")]
         (cu/install-archive! url dir))))

    (teardown! [_ test node]
      (info node "tearing down dumbo"))))

(defn with-ssh-dummy
  "Jam the dummy bit into the :ssh options.

  Our environment does not allow us to actually SSH around, so all of our
  testing will be done locally. Whee!"
  [opts]
  (assoc opts :ssh (assoc (:ssh opts) :dummy? true)))

(defn dumbo-test
  "Given an options map from the command line runner (e.g. :nodes, :ssh,
    :concurrency, ...), constructs a test map."
  [opts]
  (merge tests/noop-test
         (with-ssh-dummy opts)
         {:name "dumbo"
          :os os/noop
          :db (dumbo-db "v3.1.5")}))

(defn -main
  "Handles command line arguments. Can either run a test, or a web server for
  browsing results."
  [& args]
  (cli/run! (cli/single-test-cmd {:test-fn dumbo-test})
            args))