Code to reproduce flosell/lambdacd#110

core.clj

(ns reproduce-hanging-lambdacd.core
  (:require
    [ring.server.standalone :as ring-server]
    [lambdacd.ui.ui-server :as ui]
    [lambdacd.runners :as runners]
    [lambdacd.util :as util]
    [lambdacd.core :as lambdacd]
    [clojure.tools.logging :as log]
    [compojure.core :as compojure]
    [lambdacd.event-bus :as event-bus]
    [clojure.core.async :as async]
    [lambdacd.steps.manualtrigger :as manualtrigger]
    [lambdacd.steps.control-flow :refer [either in-parallel]]
    [lambdacd.steps.shell :as shell])
  (:gen-class))

(defn printer [ctx]
  (let [ch (-> (event-bus/subscribe ctx :step-result-updated)
                  (event-bus/only-payload))]
    (async/go-loop []
      (println (str "[PIPELINE " (:nr (:config ctx)) "] " (async/<! ch)))
      (recur))
    ch))

(defn some-step-that-does-nothing [args ctx]
  {:status :success})

(defn some-step-that-echos-foo [args ctx]
  (shell/bash ctx "/" "echo foo"))

(defn some-step-that-echos-bar [args ctx]
  (shell/bash ctx "/" "echo bar"))

(defn some-failing-step [args ctx]
  (shell/bash ctx "/" "echo \"i am going to fail now...\"" "exit 1"))

(def pipeline-def
  `((either
      manualtrigger/wait-for-manual-trigger
      )
     some-step-that-does-nothing
     (in-parallel
       some-step-that-echos-foo
       some-step-that-echos-bar)
     manualtrigger/wait-for-manual-trigger
     some-failing-step))

(defn mk-pipeline [nr]
  (let [config   {:home-dir (util/create-temp-dir)
                  :name     (str "reproduce hanging lambdacd " nr)
                  :nr       nr}
        ;; initialize and wire everything together
        pipeline (lambdacd/assemble-pipeline pipeline-def config)
        app      (ui/ui-for pipeline)]
    (printer (:context pipeline))
    (runners/start-one-run-after-another pipeline)
    (log/info "started pipeline" nr)
    (compojure/context (str "/" nr) [] app)))

(defn -main [& args]
  (let [uis (map mk-pipeline (range 100))
        app (apply compojure/routes uis)]
    (ring-server/serve app {:open-browser? false
                            :port          8080})))

project.clj

(defproject reproduce-hanging-lambdacd "0.1.0-SNAPSHOT"
            :description "FIXME: write description"
            :url "http://example.com/FIXME"
            :dependencies [[lambdacd "0.9.0"]
                           [lambdacd-value-stream "0.1.0"]
                           [lambdacd-git "0.1.2"]
                           [lambdacd-cron "0.1.1"]
                           [ring-server "0.3.1"]
                           [org.clojure/clojure "1.7.0"]
                           [org.clojure/tools.logging "0.3.0"]
                           [org.slf4j/slf4j-api "1.7.5"]
                           [ch.qos.logback/logback-core "1.0.13"]
                           [ch.qos.logback/logback-classic "1.0.13"]]
            :profiles {:uberjar {:aot :all}}
            :main reproduce-hanging-lambdacd.core)