question: How to mutate an image's platform

[joshwlewis]

I commonly deal with images that I know were compiled for a specific architecture, but have a blank architecture in the config. This is pretty common for Cloud Native Buildpack buildpack images create via pack buildpack package.

For instance, this image has linux/amd64 compiled binaries in it:

$ crane config heroku/buildpack-nodejs:3.0.3 | jq '.architecture'
""

I'd like to mutate the image config to the appropriate architecture to prevent incorrect usage. I've tried several variations of crane mutate, but the --platform flag doesn't seem to have an impact on the resulting image. For instance, this doesn't mutate the image:

$ crane mutate heroku/buildpack-nodejs:3.0.3 --platform linux/amd64
2024/04/10 14:52:49 existing manifest: 3.0.3@sha256:30da467ff00b5597ad531cdad6b9ca52f86987dfc85da0504a55f3523bd0fd8b
index.docker.io/heroku/buildpack-nodejs@sha256:30da467ff00b5597ad531cdad6b9ca52f86987dfc85da0504a55f3523bd0fd8b

Should crane support this? Or maybe there's some other way to achieve this with crane?

[joshwlewis]

I went ahead and opened #1919 as a potential solution.

[joshwlewis]

Closing -- support was added in #1919.