Control sorting of image versions

[jhamman]

I am using this action to get the latest image version from the repo2docker repository: https://hub.docker.com/r/jupyter/repo2docker/tags

The repo2docker team produces a new image (tag) for every git commit and tag. Currently the latest commit image is jupyter/repo2docker:0.11.0-20.g070e4a9 and the latest git-tag image is jupyter/repo2docker:0.11.0.

From what I can tell, Semver sort is always going to return the latter (i.e. 0.11.0) and not the latest commit tag:

gha-get-docker-hub-tags/main.go

Line 72 in 4d1339c

semver.Sort(tags)

Is this something we can control? (I want the latest commit tag)

[jacobtomlinson]

Hmm interesting point. In theory I would expect 0.11.0-20.g070e4a9 to sort as newer than0.11.0 as it is 20 commits ahead. But perhaps there is some logic that ignores commit tags like this.

We use this library to do the sorting. Maybe an issue there would be helpful to clarify the designed logic of the sort.

[jhamman]

package main

import (
	"fmt"
	"github.com/coreos/go-semver/semver"
)

func main() {

	raw := []string{"0.11.0-20.g070e4a9", "0.12.0", "0.11.0"}
	raw := []string{"0.11.0-20.g070e4a9", "0.12.0", "0.11.0"}
	fmt.Println(fmt.Sprintf(`Unsorted Tags::%s`, raw))
	var tags []*semver.Version
	for _, r := range raw {	
		tags = append(tags, semver.New(r))
	}
	semver.Sort(tags)
	fmt.Println(fmt.Sprintf(`Sorted Tags (oldest -> newest)::%s`, tags))
}

yields:

$go run test.go
Unsorted Tags::[0.11.0-20.g070e4a9 0.12.0 0.11.0]
Sorted Tags (oldest -> newest)::[0.11.0-20.g070e4a9 0.11.0 0.12.0]

So at least we have a way to isolate this behavior.

[jhamman]

opened an issue upstream: Masterminds/semver#149

[minrk]

prerelease tags are supposed to be sorted before the stable release they refer to (i.e. 0.1.0-beta < 0.1.0). So when using these as post-build suffixes, we should be using + as the separator for post-build metadata or incrementing the version, i.e. 0.2.0-n123 for "pre-0.2"