hot-replace build / build with symlink

[Suven]

Body

Summary

I want to be able to reexecute npm run build without downtimes. So if a dist-folder is already present, I would want build to build to somewhere else, and then swap those folders, if/when building succeeded.

Background & Motivation

I want to use Astro for a static site but still allow CMS-Changes via statamic. I have no fast rebuild-requirements. For my needs it would be enough to rebuild every few minutes (maybe via cron). I am also not using a CDN / hoster like vercel which would me allow to do that easily. I am using classic bare metal webservers.

Goals

• Keep the current build-experience as is, for fresh builds
• Make incremental builds 0-config swapping.

Example

• Instead of building to the desired directory, run build builds into .$target
• When finished, it runs rm -rf ${target} && mv ".$target" $target

[delucis]

astro build does support an --outDir flag, so maybe that helps to do this already?

I’d probably opt for something like this in your package.json:

{
  "scripts": {
    "build": "astro build --outDir _temp && rm -rf dist && mv _temp dist"
  }
}

It’s not 100% zero downtime I guess though because there is a brief gap between files being deleted and replaced. Depends on your requirements.

[jase-languasco]

Instead of deleting and moving the new directory you can copy the contents into the build directory and then delete the temporary directory

astro build --outDir _temp && cp -r _temp/* dist && rm -rf _tmp

[delucis]

That won’t remove old assets from dist/ that are no longer needed though, so depends a bit on if that’s acceptable or not. Could mean outdated files accumulate over time.

[Suven]

Rsync supports that. One could do something like rsync -av --progress --checksum --delete ./dist/client/ ./serv. It's also a bit faster as it skips identical files.

I'd still argue that not temporarily destroying the dist-folder while (re)building would be a nice default behaviour.

[monaye]

try using the symbolic instead of dis folder. so dist look at the build output folder.

date=$(date +%Y%m%d%H%M%S) && astro build --outDir build/$date && ln -sfn build/$date dist

this will create a new folder for each build and override the symbolic link.