Document how to specify multiple names in the docker build --output type=image,name=... option

[jlhawn]

Is this a docs issue?

• My issue is about the documentation content or website

Type of issue

I can't find what I'm looking for

Description

The docs website doesn't give an explicit example of how to specify multiple image names when using the --output type=image,name=... option of Docker Builds.

Location

https://docs.docker.com/build/exporters/image-registry/

Suggestion

The buildkit maintainers @tonistiigi and @thaJeztah made these comments about 5 years ago which are very helpful: moby/buildkit#797 (comment)

I think it would be good to include those examples in the official documentation. The buildkit README already does this: https://github.com/moby/buildkit/blob/master/README.md#imageregistry

[thaJeztah]

@jlhawn !!! That's been a while, how are you doing??

[jlhawn]

@jlhawn !!! That's been a while, how are you doing??

I'm doing well! I'm still working on devops but getting into data engineering too. How about you? I think of you every time I see stroopwafels 😆

[jlhawn]

oh! one more thing to add to this issue: it would be good to mention how the name option works in conjuction with the -t, --tag flag on docker builds.

[tonistiigi]

Docker users should not need to use the name= inside the --output CSV. Just set -t/--tag and you can set multiple values for multiple names. The outputs that support names pick up the values from --tag.

Link above is from buildctl that doesn't have a --tag flag.