How to serve angular cli app before running cypress in CI?

I wasn't satisfied with any of the answers provided, so I came up with the following:

Step 1: Install dev dependencies

npm install --save-dev concurrently wait-on

Step 2: Write the following scripts in your package.json:

"scripts": {
  "start": "ng serve",
  ...
  "cy:open": "cypress open",
  "cy:run": "cypress run",
  "e2e": "concurrently \"npm run start\" \"wait-on http-get://localhost:4200 && npm run cy:run\" --kill-others --success first",
  "e2e-gui": "concurrently \"npm run start\" \"wait-on http-get://localhost:4200 && npm run cy:open\" --kill-others --success first",
  ...
}

Then you can run npm run e2e or npm run e2e-gui.

Voila!

Latest Cypress updates already include Angular schematics to simplify tests integration into an existing project.

As simple as: ng add @cypress/schematic

and then ng e2e