Error when consuming vendored Go code

[cueckoo]

Originally opened by @ekarlso in cuelang/cue#402

Hi guys, I have tried to do something like

go get github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/...
cue get go github.com/coreos/prometheus-operator/vendor/v1

This is the code

import (
  monitoringv1 "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1"
)
// Validation Code
#PrometheusSpec: {
	monitoringv1.#PrometheusSpec
	storageSpec: null | monitoringv1.#StorageSpec
}

Then when I I get errors

cue vet -c
prometheusRelease."prometheus-operator".spec.values.prometheus.prometheusSpec.storageSpec: incomplete value ((null | C{disableMountSubPath?: bool @go(DisableMountSubPath), emptyDir?: (null | _|_(reference "#EmptyDirVolumeSource" not found)) @go(EmptyDir,*github.com/coreos/prometheus-operator/vendor/v1.EmptyDirVolumeSource), volumeClaimTemplate?: #EmbeddedPersistentVolumeClaim @go(VolumeClaimTemplate)})):

After digging into the monitoringv1 code I can see that EmptyDirVolumeSource is not included, any way to hack it together ? 🙂 (edited)

[cueckoo]

Original reply by @gogommartin in cuelang/cue#402 (comment)

From the syntax in your example I'm pretty sure you're using cue v0.2.0. For reference, I'm using v0.2.0 in this example.

Unfortunately, I wasn't able to replicate the problem you're encountering. Here are the steps that I took:

$ cue version
cue version 0.2.0 darwin/amd64
$ go get github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/...
$ cue get go github.com/coreos/prometheus-operator/vendor/v1
$ cat example.cue
package example

import (
        monitoringv1 "github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1"
)

#PrometheusSpec: {
        monitoringv1.#PrometheusSpec
        storageSpec: null | monitoringv1.#StorageSpec
}
$ cue vet -c
$ echo $?
0

Here are the references to EmptyDirVolumeSource in my cue.mod directory, does this align with yours?

$ rg EmptyDirVolumeSource
cue.mod/gen/github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/types_go_gen.cue:426:// EmptyDirVolumeSource to be used by the Prometheus StatefulSets. If specified, used in place of any volumeClaimTemplate. More
cue.mod/gen/github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/types_go_gen.cue:428:emptyDir?: null | #EmptyDirVolumeSource @go(EmptyDir,*github.com/coreos/prometheus-operator/vendor/v1.EmptyDirVolumeSource)

I've found that with cue get go it is useful to also use a go module so that you can specify the exact versions of the go libraries you want to use in cue. You could do so with something like this:

$ go mod init example.com
$ go get github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/...@v0.39.0
$ cue get go github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/...

After I pinned the version of prometheus-operator that resulted in a different generated cue.mod directory:

$ rg EmptyDirVolumeSource
cue.mod/gen/k8s.io/api/core/v1/types_go_gen.cue:53:emptyDir?: null | #EmptyDirVolumeSource @go(EmptyDir,*EmptyDirVolumeSource) @protobuf(2,bytes,opt)
cue.mod/gen/k8s.io/api/core/v1/types_go_gen.cue:708:#EmptyDirVolumeSource: {
cue.mod/gen/github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/types_go_gen.cue:417:// EmptyDirVolumeSource to be used by the Prometheus StatefulSets. If specified, used in place of any volumeClaimTemplate. More
cue.mod/gen/github.com/coreos/prometheus-operator/pkg/apis/monitoring/v1/types_go_gen.cue:419:emptyDir?: null | v1.#EmptyDirVolumeSource @go(EmptyDir,*v1.EmptyDirVolumeSource)

The definition for EmptyDirVolumeSource has changed here so I suspect the issue you're encountering may be due to usage of the master branch of prometheus-operator via go get ... without an explicit version specified.

I'm new to cue and haven't written any go in years so the go module system is new to me and I may be leveraging it incorrectly so take this with a grain of salt.

[cueckoo]

Original reply by @ekarlso in cuelang/cue#402 (comment)

Actually not I was on master :)