Based on this tutorial Standing up Backstage, the steps for creating a Backstage App are:
The installation of the Backstage instance is performed upon initialization of the Gitpod workspace. Just sit back and relax while yarn does its thing. It will create a directory myapp into which your Backstage Portal is created. When done it will run the app as well - using yarn dev (in a terminal) from the myapp directory.
The Backstage app will start both the backend and frontend app. When the terminal shows the line [0] Webpack compiled successfully, the Backstage app will be ready. You can then access the Backspace app at http://localhost:3000/.
Note: this will work from VS Code Desktop (local terminal) - with local port forwarding. Not when running in the browser based environment: the Backstage frontend app accesses the backend API at localhost port 7007. That means that this port must both be forwarded and made public.
You should find your Developer Portal in good working order. Explore around - see what it has to offer in its bare, default form.
For example:
Then you could start extending and fine tuning. Add some plugins, change the configuration of the portal as it currently stands.
See for example: Configuring Plugins
You may now want to work your way through this tutorial: Onboarding Software to Backstage
The default installation of Backstage uses SQLLite as its backend database (in memory, non-persistent acrocss workspace restarts or even Backstage restarts). The workspace already has a running PostgreSQL database and the root directory of the VS Code project contains the file app-config.local.yaml that has the configuration for this database as the backend. By moving this file to the myapp directory and restarting Backstage (yarn dev in the myapp directory) should switch Backstage from SQLLite to PostgreSQL (as explained here).
Note: this does not seem to work as expected. Some more experiments seem required to get this to work properly.
To explore the PostgreSQL instance, use these commands:
docker exec -it backstage-postgres psql --host=localhost --dbname=postgres --username=postgres
\l
\c postgres
\dt
to connect to the database using PSQL in the container running the database, connecting as user postgres - list the database, switch to using the postgres database and list the currently available tables in that schema.
Instead of locally installing & running Backage, you can try out Backstage in the public demo environment: https://demo.backstage.io/catalog?filters%5Bkind%5D=component&filters%5Buser%5D=owned
Introduction Backstage for All - concepts, objectives, terminology: https://backstage.spotify.com/learn/backstage-for-all/backstage-for-all/1-introduction/
Onboarding software to Backstage: https://backstage.spotify.com/learn/onboarding-software-to-backstage/
Medium article - Backstage by Example (Part 1)
Standing up Backstage (creating your first app) - https://backstage.spotify.com/learn/standing-up-backstage/standing-up-backstage/1-intro/