🐛 Override the Golang version by config

.gitignore

@@ -18,6 +18,7 @@
 /openshift
 /openshift-knative
 /konflux-gen/out
+_output/
 # TODO: Remove
 rpms.lock.yaml
 

config/serverless-operator.yaml

@@ -38,6 +38,7 @@ config:
         version: "4.14"
       promotion: {}
     release-1.35:
+      golangVersion: "1.24"
       konflux:
         enabled: true
         excludes:

pkg/dockerfilegen/generator.go

@@ -17,6 +17,7 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/openshift-knative/hack/config"
 	"github.com/openshift-knative/hack/pkg/soversion"
 
 	"github.com/coreos/go-semver/semver"
@@ -150,12 +151,6 @@ func generateDockerfile(params Params, mainPackagesPaths sets.Set[string]) error
 	if err != nil {
 		return err
 	}
-	goVersion := goMod.Go.Version
-
-	// The builder images are distinguished by golang major.minor, so we ignore the rest of the goVersion
-	if strings.Count(goVersion, ".") > 1 {
-		goVersion = strings.Join(strings.Split(goVersion, ".")[0:2], ".")
-	}
 
 	metadata, err := project.ReadMetadataFile(params.ProjectFilePath)
 	if err != nil {
@@ -167,6 +162,11 @@ func generateDockerfile(params Params, mainPackagesPaths sets.Set[string]) error
 		metadata = project.DefaultMetadata()
 	}
 
+	var goVersion string
+	if goVersion, err = resolveGolangVersion(params, goMod, metadata); err != nil {
+		return err
+	}
+
 	rhelVersion := RHEL9
 	templateFilePattern := "dockerfile-templates/rhel-9/*.tmpl"
 	var soVersion string
@@ -400,6 +400,84 @@ func generateDockerfile(params Params, mainPackagesPaths sets.Set[string]) error
 	return nil
 }
 
+func resolveGolangVersion(params Params, goMod *modfile.File, metadata *project.Metadata) (string, error) {
+	goVersion := goMod.Go.Version
+
+	// The builder images are distinguished by golang major.minor, so we ignore the rest of the goVersion
+	if strings.Count(goVersion, ".") > 1 {
+		goVersion = strings.Join(strings.Split(goVersion, ".")[0:2], ".")
+	}
+
+	log.Println("Golang version (from go.mod):", goVersion)
+
+	branch := strings.Replace(metadata.Project.Tag, "knative-", "release-", 1)
+	nvBranch := strings.Replace(branch, "release-v", "release-", 1)
+	soVer, err := soversion.SoFromUpstreamVersion(nvBranch)
+	reponame := params.GetRepoName(goMod)
+
+	resolver := golangResolver{
+		defaultVersion: goVersion,
+		params: []golangResolverParams{
+			{reponame, branch},
+			{reponame, nvBranch},
+		},
+	}
+
+	if err == nil {
+		soRelease := soversion.BranchName(soVer)
+		resolver.params = append(resolver.params, golangResolverParams{
+			"serverless-operator", soRelease,
+		})
+	}
+
+	return resolver.perform()
+}
+
+type golangResolverParams struct {
+	reponame, branch string
+}
+
+type golangResolver struct {
+	defaultVersion string
+	params         []golangResolverParams
+}
+
+func (r golangResolver) perform() (string, error) {
+	goVersion := r.defaultVersion
+	for _, check := range r.params {
+		configGoVersion, err := resolveGolangVersionForRepo(check.reponame, check.branch)
+		if err != nil && !errors.Is(err, ErrCantFindConfig) {
+			return "", err
+		}
+		if configGoVersion != "" {
+			goVersion = configGoVersion
+			log.Println("Golang version (overridden for", check.reponame, "@", check.branch, "):", goVersion)
+			break
+		}
+	}
+	return goVersion, nil
+}
+
+var ErrCantFindConfig = errors.New("can't find config file")
+
+func resolveGolangVersionForRepo(reponame string, branchName string) (string, error) {
+	cfgYaml, err := config.Configs.ReadFile(fmt.Sprint(reponame, ".yaml"))
+	if err != nil {
+		return "", fmt.Errorf("%w: %w", ErrCantFindConfig, err)
+	}
+	prowcfg, perr := prowgen.UnmarshalConfig(cfgYaml)
+	if perr != nil {
+		return "", errors.WithStack(perr)
+	}
+
+	branch := prowcfg.Config.Branches[branchName]
+	if branch.GolangVersion != "" {
+		goVersion := branch.GolangVersion
+		return goVersion, nil
+	}
+	return "", nil
+}
+
 func hasVendorFolder(dir string) (bool, error) {
 	info, err := os.Stat(path.Join(dir, "vendor"))
 	if err == nil {

pkg/dockerfilegen/params.go

@@ -7,6 +7,7 @@ import (
 	"github.com/octago/sflags"
 	"github.com/octago/sflags/gen/gpflag"
 	"github.com/spf13/pflag"
+	"golang.org/x/mod/modfile"
 )
 
 type Params struct {
@@ -20,6 +21,7 @@ type Params struct {
 	DockerfilesBuildDir          string   `json:"dockerfiles-build-dir" desc:"Dockerfiles output directory for build image relative to output flag"`
 	DockerfilesSourceDir         string   `json:"dockerfiles-source-dir" desc:"Dockerfiles output directory for source image relative to output flag"`
 	ProjectFilePath              string   `json:"project-file" desc:"Project metadata file path"`
+	RepoName                     string   `json:"repo-name" desc:"Repository name (implied from go.mod by default)"`
 	DockerfileImageBuilderFmt    string   `json:"dockerfile-image-builder-fmt" desc:"Dockerfile image builder format"`
 	AppFileFmt                   string   `json:"app-file-fmt" desc:"Target application binary path format"`
 	RegistryImageFmt             string   `json:"registry-image-fmt" desc:"Container registry image format"`
@@ -40,6 +42,13 @@ func (p *Params) ConfigureFlags() (*pflag.FlagSet, error) {
 	return fs, nil
 }
 
+func (p *Params) GetRepoName(goMod *modfile.File) string {
+	if p.RepoName != "" {
+		return p.RepoName
+	}
+	return path.Base(goMod.Module.Mod.Path)
+}
+
 func DefaultParams(wd string) Params {
 	return Params{
 		RootDir: wd,

pkg/prowgen/prowgen_config.go

@@ -91,6 +91,7 @@ type Branch struct {
 	SkipE2EMatches         []string    `json:"skipE2EMatches,omitempty" yaml:"skipE2EMatches,omitempty"`
 	SkipDockerFilesMatches []string    `json:"skipDockerFilesMatches,omitempty" yaml:"skipDockerFilesMatches,omitempty"`
 	Konflux                *Konflux    `json:"konflux,omitempty" yaml:"konflux,omitempty"`
+	GolangVersion          string      `json:"golangVersion,omitempty" yaml:"golangVersion,omitempty"`
 
 	// DependabotEnabled enabled if `nil`.
 	DependabotEnabled *bool `json:"dependabotEnabled,omitempty" yaml:"dependabotEnabled,omitempty"`

pkg/soversion/version.go

@@ -5,9 +5,18 @@ import (
 	"strings"
 
 	"github.com/coreos/go-semver/semver"
+	"github.com/pkg/errors"
 )
 
 func FromUpstreamVersion(upstream string) *semver.Version {
+	ver, err := SoFromUpstreamVersion(upstream)
+	if err != nil {
+		panic(fmt.Sprintf("%+v", err))
+	}
+	return ver
+}
+
+func SoFromUpstreamVersion(upstream string) (*semver.Version, error) {
 	upstream = strings.Replace(upstream, "release-v", "", 1)
 	upstream = strings.Replace(upstream, "release-", "", 1)
 	upstream = strings.Replace(upstream, "v", "", 1)
@@ -16,7 +25,10 @@ func FromUpstreamVersion(upstream string) *semver.Version {
 	if len(dotParts) == 2 {
 		upstream = upstream + ".0"
 	}
-	soVersion := semver.New(upstream)
+	soVersion, err := semver.NewVersion(upstream)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
 	for i := 0; i < 21; i++ { // Example 1.11 -> 1.32
 		soVersion.BumpMinor()
 	}
@@ -29,7 +41,7 @@ func FromUpstreamVersion(upstream string) *semver.Version {
 		soVersion.Minor -= 1
 	}
 
-	return soVersion
+	return soVersion, nil
 }
 
 func ToUpstreamVersion(soversion string) *semver.Version {