Heroku

Installation

• Windows 10 Laptop

Concepts

• all Heroku applications run in a collection of lightweight Linux containers called Dynos. To find out the dynos:

heroku ps

• Procfiles can contain additional process types. For example, you can declare a background worker that processes items off a queue.
• The set of dynos declared in your Procfile and managed by the dyno manager via heroku ps:scale are known as the dyno formation. These dynos do the app’s regular business (such as handling web requests and processing background jobs) as it runs. When you wish to do one-off administrative or maintenance tasks for the app, or execute some task periodically using Heroku Scheduler, you can spin up a one-off dyno.

Interface

• Dashboard login with user, password and Salesforce App on mobile

Config and Environment Variables

• config variables are static and available via heroku config or via the Heroku Dashboard
• environment variables are dynamic and are available via heroku run env

Add Ons

Databases

• documentation
• connection information see config var DATABASE_URL [database type]://[username]:[password]@[host]:[port]/[database name]

Postgres

• DB info dashboard -> <APPLICATION> -> Resources

Operation

Delete Application

heroku apps:destroy uweheuer-capstone

List all Applications

heroku apps

List all Domains (for Applications)

heroku domains

Logging

• via dasboard

• or via command line

heroku logs --tail

Example

Official Tutorial

• from official python tutorial

PS C:\Temp\python-getting-started> heroku login

• clone example
• create app and push code
• start the app

PS C:\Temp\python-getting-started> heroku ps:scale web=1
Scaling dynos... done, now running web at 1:Free
PS C:\Temp\python-getting-started> heroku open
// opens https://arcane-peak-78109.herokuapp.com/

• open the dashboard
• stop it or scale it down to 0

heroku ps:scale web=0

• prepare for running locally

PS C:\Temp\python-getting-started> python -m venv venv
PS C:\Temp\python-getting-started> .\venv\Scripts\activate
(venv) PS C:\Temp\python-getting-started> pip install -r .\requirements.txt

• run it locally

(venv) PS C:\Temp\python-getting-started> python manage.py collectstatic
(venv) PS C:\Temp\python-getting-started> heroku local -f .\Procfile.windows

• open it http://localhost:5000/

Spring Boot Demo

Configuration for Heroku

• steps from offical Spring Boot tutorial
• create demo1 application in C:\Uwes\Programme\eclipse\workspace\demo1 and git it
• see SpringBoot.docx
• When deploying an app, Heroku reads pom.xml file and installs the dependencies by running mvn clean install.
• check DB connection by

C:\Uwes\Programme\PostgreSQL\12\bin> .\psql -h ec2-3-230-122-20.compute-1.amazonaws.com -U cepxizounlueue defpfuas3qslld

• set specific configurations for Heroku by adding profile heroku to pom.xml and set config var MAVEN_CUSTOM_OPTS to -P !local_dev,heroku

Run on Heroku

git push heroku master
heroku open // opens the application https://intense-caverns-96515.herokuapp.com/ in a browser

Prepare Locally Heroku

• create Procfile Procfile.windows for running locally with command to start the Spring application java -jar target/demo1-0.0.1-SNAPSHOT.jar
• compile and build a JAR, with dependencies, placing it into your application’s target directory. The spring-boot-maven-plugin in the pom.xml provides this process

mvn install

• create local DB

C:\Uwes\Programme\xampp7.2.27\mysql\bin\mysql --user=root --password=mHalloo0@1m
  create database demo1;

• create C:\Uwes\eclipse\workspace_2020-12\SpringBoot\demo1\set_local_dev.bat
• add profile local_dev to pom.xml

Run Heroku Locally

• run the application

set_local_dev.bat
// start eclipse by start_eclipse.bat from shell and run it or
heroku local -f Procfile.windows

Run Eclipse Locally

• see src\main\resources\application.properties which is not in Git repository
• start eclipse

Resources

• Tutorial
• Heroku dashboard