Environments

dev is the working copy

Every change to a site lands in dev, whether you ask the MCP for it, edit a page in place, or publish a whole new set of files. Nothing anyone relies on is ever served from dev.

Every other environment is read-only. You can't publish to prod or edit a page in it, even as an administrator. If you ask the MCP to change prod directly it will refuse and explain that the change goes to dev and reaches prod by promote. This is deliberate: it means everything people see has been looked at in dev first.

The order

A new site has two environments, dev and prod. You can add more between them, such as stage for a review by a wider group, or test.

• dev is always first and prod always last. Neither can be moved or deleted.
• A new environment goes between them. With only dev and prod there's one place for it; with more, you say which environment it follows.
• Each new environment gets its own address, <site>--<environment>.pages.plexara.pmgsc-data.org, which an administrator switches on.

Promoting

Promotion goes one step at a time. An environment takes a release only from the environment immediately before it, and only the release that environment is serving right now. With dev, stage, prod:

• stage takes what dev serves.
• prod takes only what stage serves, never straight from dev.

Promote copies no files. It moves the environment's pointer to the same release, so what reaches prod is exactly what was reviewed in the step before. It takes effect immediately on every server.

Rolling back

If something's wrong after a promote, roll the environment back. It returns to the release it served before (or any earlier release it served that's still kept), immediately. Rolling back prod doesn't touch dev, so you can fix the problem there and promote again.

Requiring approval

Any environment can be set to require approval. Then:

• A release reaches it only by promote, and someone who isn't an administrator files a request in Approvals first. Once it's approved, they promote again and it goes through.
• The approval request shows exactly which files were changed, added and removed, and any new redirects.
• Making one of that environment's domains public also goes through Approvals.
• Only an administrator can take approval off an environment, or move an environment past one that requires approval.

Use it on prod for anything public-facing or anything an outside group relies on.

The main address

A site's main address, <site>.pages.plexara.pmgsc-data.org, shows one environment the owner chooses: prod on a new site. The owner (or an administrator) can give it to another environment, or to none, in which case it shows a "Nothing is published here" page. Every environment also keeps its own <site>--<environment> address, whichever one holds the main address.

Releases kept

Each environment keeps its last 50 distinct releases, so you can roll back to any of them. A daily cleanup removes older ones. A release stays as long as any environment is serving it, an application depends on it, or an approval request names it. The owner or an administrator can change how many an environment keeps, including keeping every release.