Deploying a custom ghost build on Render

I made a fork of Ghost and added some changes to core files (server side), specifically the email template. Things work fine locally, but now I’m at a loss as to how to deploy it to production. I’m looking to use Render as my hosting service, but there are only instructions on how to use a ready-made Ghost docker image, nothing custom.

Was wondering if anyone else had experience with this.

Continue the answer from Deploying a custom ghost build in production - Installation - Ghost Forum
Once you have a zip with your build, you can modify the Ghost official Dockerfile, which is the base image of Render’s Ghost example.

I create a repo with example Dockerfile.
I also commit to this repo.
In the Dockerfile the Ghost client will install Ghost from that zip file.
You can fork this repo, replace the zip file with yours (remember to change filename in the Dockerfile), and create a Docker Web Service in Render by this document, or just click the “Deploy to Render” link in the repo’s README.