script.clj

(defn- hadoop-service
  "Run a Hadoop service"
  [request hadoop-daemon description]
  (let [hadoop-home (parameter/get-for-target request [:hadoop :home])
        hadoop-user (parameter/get-for-target request [:hadoop :owner])]
    (->
     request
     (exec-script/exec-checked-script
      (str "Start Hadoop " description)
      (as-user
       ~hadoop-user
       ~(script/with-template [:ubuntu]
          (stevedore/script
           (if-not (pipe (jps)
                         (grep "-i" ~hadoop-daemon))
             (str ~hadoop-home
                  "/bin/hadoop-daemon.sh"
                  " start "
                  ~hadoop-daemon)))))))))


;; Start Hadoop Name Node...
;; 2445 NameNode
;; ...done
;; hadoop dfsadmin -safemode wait...
;; Safe mode is OFF
;; ...done
;; hadoop fs -mkdir /tmp/node-name/data...
;; mkdir: cannot create directory /tmp/node-name/data: File exists
;; hadoop fs -mkdir /tmp/node-name/data failed
;; logout

(pallet.script/with-template
                   [:ubuntu]
                   (pallet.stevedore/script
                    (if (pipe
                     (jps)
                     (grep "-i" "namenode"))
                        (println (quoted "it worked")))))