Run an app or a database

This tutorial gets your own code running on Coritan with a database beside it. Two products do the work. Apps builds your app from a git repository and serves it over HTTPS, at its own address and on your domain. Container Apps runs one program from a catalogue on a server of its own, here a PostgreSQL database. Sections 1 to 3 deploy the app, sections 4 and 5 run the database, and section 6 connects them. To run only a database, start at section 4.

An app has no plan and no invoice (How Apps is billed). The database server costs the plan you choose on its order page. If you are not sure which product suits your code, read Container Apps, Cloud Compute and Apps compared first.

• A Coritan account. Create an account if you have none, then sign in.
• Your app in a git repository on a public host, such as GitHub, that answers over HTTPS. For a private repository, an access token from your git host that can read it.
• An app that listens on the port in its PORT variable and answers HTTP requests for / (What your app must do).
• For the database, credit for the server's first invoice, or a card or PayPal to pay it when you order (Add credit to your balance).
• psql, PostgreSQL's command-line client, on your computer.

1. In the dashboard, go to Apps and select New app….
2. Under App, type a Name, such as Web shop. The hint under it shows the address the app will answer at.
3. Under Source, choose Git repository. Fill in Repository with the repository's HTTPS address, such as https://github.com/example/web-shop, and change Branch when the app is not on main. Fill in Access token when the repository is private.
4. Under Regions, leave Every region chosen, and Replicas per region at 1.
5. Under Run, set Health check path to a path your app answers, / at first, and choose a Size.
6. Leave Start the first deployment now ticked, and select Create app.
7. In the Push webhook secret dialog, select Copy all and keep what it copies, then select I have saved it. You need it only to deploy on every push (Deploy on every push).

The first deployment's page opens, and its Build log follows the build (Create an app).

Coritan builds an image from your branch, then starts the replicas and requests your health check path on each one. The deployment's progress bar says what it is doing, such as Building or Starting replicas.

Once the deployment is Ready, the app is Live. Open its platform address, such as https://web-shop.apps.example.net, which the app's header shows with a copy button. Your app answers over HTTPS (Read a deployment and its build log).

1. On the app's page, select the Domains tab, then Add domain….
2. In Domain, type the name, such as www.example.com, and select Add domain.
3. At your DNS host, create the TXT record that Prove the domain is yours gives, and the CNAME record that Send its visitors to the app gives. When Coritan hosts the domain's DNS, add both on the domain's DNS tab (Add, edit and delete DNS records).
4. Wait a few minutes, then select Verify on the domain's row.

The domain shows Verified, and Certificate issued once the certificate authority has checked it. Your app answers at https://www.example.com (Add a custom domain).

1. In the dashboard, go to Order a service and select PostgreSQL database under Quick start. The Container Apps order page opens with PostgreSQL chosen under Software.
2. Under Plan, choose how often to pay, then a plan under Size.
3. Under Version, keep the version the page chose, marked Default, or choose the major version your app needs.
4. Under Location, choose the data centre closest to the people who use your app.
5. Under Settings, keep the suggested Server name or type your own. You can rename the server later on its Settings tab (Rename the server).
6. Check the summary under Your order, then select the button under it. It reads Deploy server when your credit pays the first invoice, and Place order and pay when you pay on the next page.
7. If the order's page reads Order placed, payment due, pay under Pay invoice.

The order's page shows Setting up, then Your order is ready. The server appears on the Container Apps page with the status Installing while Coritan installs PostgreSQL (Order a server).

1. Open the server from the Container Apps page. The install does not start it, so select Start. The console shows PostgreSQL's own messages until it prints database system is ready to accept connections (Use the console and power controls).

2. Select the Settings tab. Under Network, Address with port shows where the database listens, such as 203.0.113.10:10565, and Copy address copies it.

3. Under Startup variables, read the user name in POSTGRES_USER, the password in POSTGRES_PASSWORD and the database's name in POSTGRES_DB (Server settings).

4. On your computer, connect with psql and the values from the tab, then type the password when it asks:

   Shell

   psql -h 203.0.113.10 -p 10565 -U pguser pgdb
   

5. At the pgdb=# prompt, give the user a password of your own:

   Text

   \password pguser
   

psql connects and shows its prompt, and after \password it connects only with your new password.

1. Open the app from Apps and select the Environment tab, then Add variable….
2. In Name, type the variable your app reads, such as DATABASE_URL. In Value, type the connection address, such as postgresql://pguser:YOUR_PASSWORD@203.0.113.10:10565/pgdb, with your new password in it.
3. Leave Secret ticked, choose Runtime only in Available at, and select Add variable.
4. Select Redeploy… in the app's header, then Redeploy. Replicas keep the variables they started with until the next deployment.

The new deployment's page opens. Once it is Ready, your app reads DATABASE_URL and stores its data in PostgreSQL (Set environment variables).

The app did not pass its health check within 10 minutes. Health check on /: the connection failed

Nothing answered on the port in the app's PORT variable. Make the app listen on that port (Replicas do not pass their health check).

Not verified yet under the domain's row

Coritan did not find the TXT record. Check its name and value at your DNS host, wait a few minutes, then select Verify again.

psql cannot connect

Check that the server's status badge says it is running, and that psql uses the port from Address with port rather than PostgreSQL's usual 5432 (Troubleshoot servers).

• Deploy on every push, so each push to the branch goes live
• Take a server snapshot of the database server before a risky change
• Store files and backups, for the files your app keeps outside the database