builder: return error if a node fails to boot

[crazy-max]

fixes #2730

With #1869 we return an error only if all nodes fail to boot but that's not a correct pattern and we should return an error if any node fails.

[tonistiigi]

I think this was intentional to make it so that if you have a multi-node builder and one of the nodes (temporarily) goes down then you can still build with rest of the builders. Eg. you could even have multiple nodes with the same arch for some redundancy.

I think it would be ok if inspect --bootstrap fails but I think then it would need some more specific condition as this Boot() function is also used in other cases.

[crazy-max]

I think this was intentional to make it so that if you have a multi-node builder and one of the nodes (temporarily) goes down then you can still build with rest of the builders. Eg. you could even have multiple nodes with the same arch for some redundancy.

Ah yes that makes sense

I think it would be ok if inspect --bootstrap fails but I think then it would need some more specific condition as this Boot() function is also used in other cases.

Looks good I'm taking a look

[crazy-max]

I think it would be ok if inspect --bootstrap fails but I think then it would need some more specific condition as this Boot() function is also used in other cases.

Looks good I'm taking a look

Boot func in builder package is only used by create and inspect command. On build we directly call driver.Boot

buildx/build/driver.go

Line 267 in 0d708c0

c, err := driver.Boot(ctx, baseCtx, r.nodes[idx].Driver, pw)

So I don't think we need anything special here.