subdir-depend-heroku-buildpack

Configure Heroku project by file listing allowing use of subfolders etc

This is based on https://github.com/timanovsky/subdir-heroku-buildpack

What it does

This buildpack looks for two files inside a user specified folder:

1. MANIFEST_GLOBAL: This specifies which files and folders you would like to keep from the root directory
2. MANIFEST_MV_TO_ROOT: This specifies any files which need to be moved to the root directory such as a Procfile

Instructions

1. Add MANIFEST_GLOBAL and MANIFEST_MV_TO_ROOT files to the sub directory containing your project. This sub directory is the PROJECT_PATH.
2. Add this buildpack as the first buildpack in the chain
3. Set PROJECT_PATH environment variable in Heroku to point to the corresponding sub directory

How it works

The buildpack looks for the MANIFEST files in the subdirectory you configured, copies and moves the required files. Then normal Heroku slug compilation proceeds.

Example

Consider a repository containing multiple Python projects with shared data and library code:

- data/
    - data.csv
- project1/
    - Procfile
    - requirements.txt
    - app.py
- project2/
    - Procfile
    - requirements.txt
    - app.py
- shared_library/
    - utils.py

You wish to deploy only project1 to Heroku. However it is a requirement that the projects Procfile is located in the root directory, while at the same time you have a shared library and dataset.

To deploy project1 to Heroku one would only need to add MANIFEST_GLOBAL and MANIFEST_MV_TO_ROOT to the project1 sub directory where MANIFEST_GLOBAL contains

data/
project1/
shared_library/

and MANIFEST_MV_TO_ROOT contains

project1/Procfile
project1/requirements.txt

The directory structure should now look like

- data/
    - data.csv
- project1/
    - Procfile
    - requirements.txt
    - app.py
    - MANIFEST_GLOBAL
    - MANIFEST_MV_TO_ROOT
- project2/
    - Procfile
    - requirements.txt
    - app.py
- shared_library/
    - utils.py

Therefore the deployed build on Heroku will be simply

- Procfile
- requirements.txt
- data/
    - data.csv
- project1/
    - app.py
    - MANIFEST_GLOBAL
    - MANIFEST_MV_TO_ROOT
- shared_library/
    - utils.py

Using gunicorn from a different folder

A standard Procfile for gunicorn will look like:

web: gunicorn sankey_app:server

Since your app is being run from a sub directory you need to tell gunicorn to change to this sub directory first. Your procfile should look like

web: gunicorn --chdir ./project1 app:server