@NgModule({
 declarations: [ ... ],
 imports: [
  SomeModule.forRoot({ apiKey1: "needs to be externalized" }),
  AnotherModule.forRoot({ apiKey2: "needs to also be externalized" })
 ],
 providers: [ ... ],
 bootstrap: [AppComponent]
})
export class AppModule { }

docker run -e API_KEY_1='somekey' -e API_KEY_2='anotherkey' -p 80:80 my-container:production