update-codegen.sh broken with go1.25 on release-0.11 and release-0.12 #2742
Description
Presubmit tests are broken on release-0.11 and release-0.12.
We are not really supporting release-0.11 anymore so that is less of an issue, but release-0.12 should definitely be fixed.
I am quite confident that they broken when the kubekins-e2e image was bumped to one with go1.25. The image is set in https://github.com/kubernetes/test-infra/blob/master/config/jobs/kubernetes-sigs/cluster-api-provider-openstack/cluster-api-provider-openstack-presubmits.yaml.
The error happens when running make generate-codegen, which calls hack/update-codegen.sh and looks like this:
+ go install k8s.io/kube-openapi/cmd/openapi-gen
go: downloading k8s.io/klog/v2 v2.120.1
go: downloading golang.org/x/tools v0.21.0
go: downloading github.com/emicklei/go-restful/v3 v3.11.0
go: downloading google.golang.org/protobuf v1.33.0
go: downloading github.com/go-logr/logr v1.4.1
go: downloading golang.org/x/sync v0.7.0
go: downloading golang.org/x/mod v0.17.0
# golang.org/x/tools/internal/tokeninternal
../../golang.org/x/[email protected]/internal/tokeninternal/tokeninternal.go:64:9: invalid array length -delta * delta (constant -256 of type int64)
make[1]: *** [Makefile:64: generate-codegen] Error 1
make[1]: Leaving directory '/home/prow/go/src/sigs.k8s.io/cluster-api-provider-openstack/orc'
make: *** [Makefile:319: generate-orc] Error 2
The issue (as far as I understand) is that the script uses a script (kube_codegen.sh) in the upstream package that builds openapi-gen outside of CAPO. This means that we have no control over the dependencies there and thus cannot fix them to work with go1.25. If I do the same go install k8s.io/kube-openapi/cmd/openapi-gen in CAPO, it works.
CAPI has a totally different way of doing this. I wonder if we should try to change to that way. See:
https://github.com/kubernetes-sigs/cluster-api/blob/a0bb17c9c2647c5aaa80acc3385bb1adfceeea36/Makefile#L1441-L1445
https://github.com/kubernetes-sigs/cluster-api/blob/a0bb17c9c2647c5aaa80acc3385bb1adfceeea36/Makefile#L456-L465