Automated heroku deploy from subfolder

Question

I know you can deploy automatically to heroku from github, but I haven't found a way to only push a subfolder from github to heroku.

From the command-line I know it is possible to do this with:

git subtree push --prefix <subfolder> heroku master 

However, I would like to know if there is a way to use the github integration with heroku to make it pull a specific subfolder automatically when a commit is added to a branch.

Answer 1

2018 Update! To enable automated deployments with heroku, you need to have admin access for the github repo you want to deploy.

In the Heroku dashboard:

Step 1) - Connect github repository to Heroku

Inside the Deploy tab, scroll to Deployment method and connect your Github account. find the repo and hit connect. heroku should be authorized as an Oauth app in your github now.

If you cannot find the repo: Either your github has not authorized Heroku or you did not create this repo and need to make sure you have admin access to it. If this is not possible, invite an admin of the repo to your heroku app by going to Access tab in Heroku Dashboard and adding the admin as a collaborator. The admin then logs into heroku and completes Step 1 here. Afterwards you can finish the following steps.

Step 2) - Set Heroku Config Var PROJECT_PATH to your server folder

Inside the Settings tab, set a config var to tell Heroku the path to find the server code you want deployed.

Example: lets say your repo name is MyRepo and it has 2 sub-folders. back-end contains a Node.js server and front-end contains a React app. Your github directory looks like this:

MyRepo/front-end/package.json MyRepo/back-end/package.json

Then you should set your config var to PROJECT_PATH in the left box and back-end in the right box.

Step 3) - Set a Heroku Buildpack that will deploy the PROJECT_PATH folder

Again inside the Settings tab, you need to add a Buildpack that will tell heroku to look for your folder instead of deploying the repo root. There should already be 1 buildpack there to tell heroku what type of server it is (javascript/node.js, python/django, etc...).

Enter this url to add buildpack https://github.com/timanovsky/subdir-heroku-buildpack.git and make sure this is at the top of the buildpack chain (drag the lines on the left to make it above any other buildpacks you have added.

Step 4) - Enable auto deploy

Inside the Deploy tab, scroll to Automatic Deploys and click the black button to enable automatic deploys

Auto Deploy complete! Now check the build logs and make sure you don't have any errors