There are many web applications available online that generates static websites. Among these projects are two unique projects developed here at FOSSASIA. These are the Open Event WebApp Generator and Yaydoc (an automatic documentation generation and deployment project.). Since Yaydoc already supports the deployment of the generated documentations to Github pages, it was just a matter of time that the deployment to Heroku is also supported.
Heroku is an excellent cloud-based platform used as a web application deployment service. Heroku provides most of its services at free of cost to the users and is excellent to host static websites provided that a little bit of tweaking is done.
For this implementation, we use the `Platform API` provided by Heroku. Stating it’s description mentioned in the documentation,
The platform API empowers developers to automate, extend and combine Heroku with other services. You can use the platform API to programmatically create apps, provision add-ons and perform other tasks that could previously only be accomplished with Heroku toolbelt or dashboard.
In order to deploy the static websites to Heroku, we need to first prepare a bundle of source code that has been compiled and is ready for execution on the Heroku runtime. This bundle is known as a Slug.
cd temp/$EMAIL/${UNIQUE_ID}_preview
mkdir -p app
cd app
curl https://nodejs.org/dist/v6.11.0/node-v6.11.0-linux-x64.tar.gz | tar xzv > /dev/null
cp $BASE/web.js
rsync -av --progress ../ . --exclude app
cd ..
tar czfv slug.tgz ./app > /dev/null
We are using the files generated for preview to bundle them in a slug. Also, we download the NodeJS runtime files since we are deploying a static website to Heroku. Along with the static files, we require bundling a NodeJS server file (web.js) that will be used to reference the static files in the application.
After preparing the Slug, we publish the static web application to Heroku. For this, we start by creating a Heroku app using the command `heroku create <app-name>`. The app name is decided by the user when he or she fills the form in the Yaydoc Web App. Following that, we request Heroku to allocate a new slug for your app. After that, we upload the slug tar file to the platform.
# Create Heroku
heroku create $APP_NAME
# Allocating new Slug
Arr=($(curl -u “:$API_KEY” -X \
-H ‘Content-Type:application/json’ \
-H ‘Accept: application/vnd.heroku+json;version=3’ \
-d ‘{“process_types”:{“web”:”node-v6.11.0-linux-x64/bin/node web.js”}}’ \
-n https://api.heroku.com/apps/${APP_NAME}/slugs | \
python -c “import sys,json; obj=json.load(sys.stdin);
print(obj[‘blob’][‘url’] + ‘\n’ + obj[‘id’])”))
# Upload the slug tar file
curl -X PUT \
-H “Content-Type:”\
--data-binary @slug.tgz \
“${Arr[0]}”
After uploading the slug to Heroku, we need to release the app. This is done using the following command.
curl -u “:$API_KEY” -X POST \
-H “Accept: application/vnd.heroku+json; version=3” \
-H “Content-Type: application/json” \
-d ‘{“slug”:”’${Arr[1]}’”}’ \
-n https://api.heroku.com/apps/$APP_NAME/releases
Releasing the application completes the process of deployment, making the documentation generated by Yaydoc up and running at the following URL: https://<app-name>.herokuapp.com/