🐛 fix cloudflare image version management

[ikesau]

Fixes #4313

Changes

• Adds a replacedBy column to the images table
• Adds a version column to the images table
• Removes the unique filename constraint on the images column
• Adds a unique constraint on filename, version
• Updates all places that select "all images" to only select images where replacedBy is null
• Updates images API functions to reflect these changes
  • the PUT route now sets the replacedBy column, and triggers a build
  • the DELETE route uses a CTE to find every image in the chain and deletes them all
    • it's possible that a user unpublishes an article and immediately deletes its images before the rebake has occurred, thus temporarily breaking the article before it's removed, but that seems unlikely

To test

CRUD

1. Create three images
2. Upload the first one, replace it with the second, and the third
3. Confirm that all 3 images are still in the DB, and that replacedBy has been set correctly
4. Delete the third image and confirm that all 3 images get deleted in Cloudflare and the DB

Baking

1. Create 2 images
2. Upload one of them, and publish it in an article
3. Confirm the image works
4. Update the image, and confirm that a bake is triggered
5. Confirm that the article still works in the meantime
6. Confirm that the updated image is used once the bake is finished

[owidbot]

Quick links (staging server):

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Login: ssh owid@staging-site-fix-image-updating

• Site-screenshots: https://github.com/owid/site-screenshots/compare/fix-image-updating
• SVG tester: https://github.com/owid/owid-grapher-svgs/compare/fix-image-updating

SVG tester:

Number of differences (default views): 1389 (1c73fd) ❌
Number of differences (all views): 452 (0bf88d) ❌

Edited: 2024-12-18 17:04:40 UTC
Execution time: 1.29 seconds

[ikesau]

Hey @danyx23 - I ended up adding a version column and applying UNIQUE(filename, version) to get around the MySQL 8 weirdness.

This way you can PUT multiple images with the same filename because the version will be incremented, but you can't POST a new image with the same filename because it will collide with the (replaced) version 0 original image.

[danyx23]

Ah this is a nice idea - the version number carries a bit of additional information which is neat.

The only small change I would still aks is to expand the comment on the DB image type definition to mention that we considered using replacedBy alone and have a unique constraint but that this doesn't work with mysql. I would then also copy this comment to the migration file (since this is where you might end up when you try to find out about why the version was added).

Nice work!