Fix single dyno mode on heroku

Author: Vidas P

CHANGELOG.md

@@ -8,7 +8,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [current]
 ### Fixed
-- Don't use `foreman` to manage multiple processes when running with `SINGLE_DYNO=1`.
+
+- Don't use `foreman` to manage multiple processes when running with
+  `SINGLE_DYNO=1`. Single-dyno mode was demoted to being used purely for trying
+  out ActiveWorkflow on Heroku (including Free plan). Functionality
+  previously provided by foreman reimplemented as a simple shell script using
+  job control functionality of bash. Fixes #9.
 
 
 ## [0.9.9.2] - 2020-09-09

README.md

@@ -27,7 +27,9 @@ A quick and easy way to check out ActiveWorkflow is by deploying it to
 All you need to do is click the button bellow and fill in the environment variables for your seed user (admin):
 `SEED_USERNAME`, `SEED_PASSWORD` (must be at least 8 characters long) and `SEED_EMAIL`.
 
-[![Deploy](https://www.herokucdn.com/deploy/button.svg)](https://heroku.com/deploy?template=https://github.com/automaticmode/active_workflow)
+[![Deploy](https://www.herokucdn.com/deploy/button.svg)](https://heroku.com/deploy?template=https://github.com/automaticmode/active_workflow&env[SINGLE_DYNO]=1)
+
+!Note!: The button above deploys ActiveWorkflow on a single dyno so it could be run using Free Heroku plan. This configuration is not recommended for production. See [Getting Started](https://github.com/automaticmode/active_workflow/wiki/Getting-Started#Running-On-Heroku) for more details.
 
 ## Usage
 

app.json

@@ -4,24 +4,18 @@
     "website": "https://github.com/automaticmode/active_workflow",
     "repository": "https://github.com/automaticmode/active_workflow",
     "stack": "container",
-    "formation": {
-      "web": {
-        "quantity": 1,
-        "size": "free"
-      }
-    },
     "env": {
         "SINGLE_DYNO": {
-          "description": "Set to '1' if you want to run all the processes in a single dyno, leave empty otherwise. Usable only for demonstration purposes. Do not run scheduler and worker dynos if running in SINGLE_DYNO mode.",
-          "value": "1"
+          "description": "Set to '1' if you want to run all the processes in a single dyno, leave '0' otherwise. Single dyno mode is only for demonstration purposes. Do not run scheduler and worker dynos if running in SINGLE_DYNO mode.",
+          "value": "0",
+          "required": false
         },
         "SEED_USERNAME": "admin",
         "SEED_PASSWORD": "password",
         "SEED_EMAIL": "admin@example.com",
         "SECRET_KEY_BASE": {
             "generator": "secret"
         },
-        "RAILS_ENV": "production",
         "RAILS_LOG_TO_STDOUT": "enabled",
         "RAILS_MAX_THREADS": "2",
         "RAILS_SERVE_STATIC_FILES": "enabled"

docker/scripts/init

@@ -46,14 +46,14 @@ fi
 # added specifically to support running ActiveWorkflow on Heroku free plan.
 # Please use multiple container configuration in production.
 
-if [ -z "${SINGLE_DYNO}" ]; then
-  # Web only
-  exec bundle exec puma
-else
+if [ "${SINGLE_DYNO}" -eq "1" ]; then
   # Simple "homegrown" process management with somewhat graceful shutdown.
   (until bundle exec puma; do sleep 1; done) &
   web_id=$!
   (until bundle exec rails runner bin/scheduler.rb; do sleep 1; done) &
   (until bundle exec script/delayed_job -n 2 run; do sleep 1; done) &
   wait $web_id
+else
+  # Web only
+  exec bundle exec puma
 fi