Continuous Integration and Deployment

We have a meteor app in production that has WebApp, Android App and IOS app. We build our deployments from Mac and deploy to the server manually . The production server runs on Ubuntu.
Everything seems to be working perfect. But now we want to make our deployment process more automated I have couple of doubts that may sound naive. Any help would be really great.

  • We were building production deployments always using Mac as we had iOS app. Is this a constraint and has the build got to be done only using a Mac. Can it be done using a Linux box. Does it have impact on HCP on iOS.
  • How is continuous integration done when iOS App is involved. Any suggestions?