Built-in way to revalidate all content on server start

[dsosborn]

Goals

1. Enable building 1 docker image to use across multiple environments that will, when revalidated, pull in content from endpoint specified by runtime variable.
2. Account for changes in production CMS between build time and run time.
3. Eliminate need to create revalidate-all api endpoint and hit this in the deployment process

Non-Goals

Background

I'm using NextJS in a docker image with Sanity as a headless CMS. I build the image using all production values. Currently I have 2 problems.

1. When I run the image in a development environment, I need to revalidate everything in order for to see the environment-specific content.
2. When I run the image on production, even though I've used all production values to build, there most likely have been changes between build time and run time that are not reflected in the content used to generate the pages at build time. Thus when the new image is run, pages are showing content that is days old.

To rectify this, I have created an API endpoint to revalidate all content. I am currently manually hitting that and actively figuring out a solution to automate that in my deployment process.

Proposal

Build in a way to optionally revalidate all content on server start.