Make Angular working with restrictive Content Security Policy (CSP)

Edited answer for @angular/cli>=8.2

From this Github thread, one can use the index property in angular.json to control the generation of the application’s HTML index:

build: {
  ...
  "configurations": {
    "production": {
      "index": {
        "input": "src/index.production.html",
         "output": "index.html"
       },
      ...
    }
  }
}

Original answer

I’ve found a way to have restrictive CSP on my production environment while still being able to use the JTI compliler for development.

• Add a second file: index.production.html to the src folder.
• Copy the contents of index.html to that file, and add the restrictive CSP header.

<meta http-equiv="Content-Security-Policy" 
content="default-src 'none';
  frame-src 'self';
  script-src 'self';
  style-src 'self' 'unsafe-inline';
  font-src 'self';
  img-src 'self' data:;
  connect-src 'self'">

• Then, add to your angular.json the following:

build: {
  ...
  "configurations": {
    "production": {
      "fileReplacements": [
        {
          "replace": "src/index.html",
          "with": "src/index.production.html"
        }
      ],
      ...
    }
  }
}

This makes sure that when you run a production build, it will use the index.production.html with the restrictive CSP, and when you’re running it locally, you can use the JTI compiler.