Nested anonymous structs cause panic when generating CRDs

[jameshochadel]

This issue was found while using controller-tools with Kubebuilder.

To reproduce:

Create a new Kubebuilder v2 project:

go mod init example.com/m
kubebuilder init --domain example.com --license apache2 --owner "Test Owner"
kubebuilder create api --group ship --version v1 --kind Frigate

In ./api/v1/frigate_types.go, modify FrigateSpec to be:

type FrigateSpec struct {
	NestedAnonymousStruct struct {
		SomeField string `json:"someField"`
	} `json:"nestedAnonymousStruct"`
}

And run make manifests.

Expected behavior: controller-get is fetched, and the CRDs are generated.
Actual behavior: I get the following panic:

go get sigs.k8s.io/controller-tools/cmd/[email protected]
go: finding sigs.k8s.io v0.2.1
go: finding sigs.k8s.io/controller-tools/cmd v0.2.1
go: finding sigs.k8s.io/controller-tools/cmd/controller-gen v0.2.1
/Users/james/go/bin/controller-gen "crd:trivialVersions=true" rbac:roleName=manager-role webhook paths="./..." output:crd:artifacts:config=config/crd/bases
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x18 pc=0x15e6f4c]

goroutine 1 [running]:
sigs.k8s.io/controller-tools/pkg/crd.structToSchema(0xc000f9cfc0, 0xc0006d4200, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:322 +0x9c
sigs.k8s.io/controller-tools/pkg/crd.typeToSchema(0xc000f9cfc0, 0x18f9420, 0xc0006d4200, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:164 +0x3a6
sigs.k8s.io/controller-tools/pkg/crd.structToSchema(0xc0007ae1e8, 0xc0006d42a0, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:375 +0x491
sigs.k8s.io/controller-tools/pkg/crd.typeToSchema(0xc0007ae1e8, 0x18f9420, 0xc0006d42a0, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:164 +0x3a6
sigs.k8s.io/controller-tools/pkg/crd.infoToSchema(...)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:107
sigs.k8s.io/controller-tools/pkg/crd.(*Parser).NeedSchemaFor(0xc0001ec0a0, 0xc00033a700, 0xc000974034, 0xb)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/parser.go:169 +0x306
sigs.k8s.io/controller-tools/pkg/crd.(*schemaContext).requestSchema(0xc000f9cf30, 0x0, 0x0, 0xc000974034, 0xb)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:99 +0x9e
sigs.k8s.io/controller-tools/pkg/crd.localNamedToSchema(0xc000f9cf30, 0xc0006d45c0, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:220 +0x1b1
sigs.k8s.io/controller-tools/pkg/crd.typeToSchema(0xc000f9cf30, 0x18f8fe0, 0xc0006d45c0, 0x1f)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:154 +0x2e9
sigs.k8s.io/controller-tools/pkg/crd.structToSchema(0xc0007aeb38, 0xc0006d4680, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:375 +0x491
sigs.k8s.io/controller-tools/pkg/crd.typeToSchema(0xc0007aeb38, 0x18f9420, 0xc0006d4680, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:164 +0x3a6
sigs.k8s.io/controller-tools/pkg/crd.infoToSchema(...)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/schema.go:107
sigs.k8s.io/controller-tools/pkg/crd.(*Parser).NeedSchemaFor(0xc0001ec0a0, 0xc00033a700, 0xc000974070, 0x7)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/parser.go:169 +0x306
sigs.k8s.io/controller-tools/pkg/crd.(*Parser).NeedFlattenedSchemaFor(0xc0001ec0a0, 0xc00033a700, 0xc000974070, 0x7)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/parser.go:181 +0xd8
sigs.k8s.io/controller-tools/pkg/crd.(*Parser).NeedCRDFor(0xc0001ec0a0, 0xc00096402e, 0x10, 0xc000974070, 0x7, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/spec.go:165 +0x61d
sigs.k8s.io/controller-tools/pkg/crd.Generator.Generate(0x5d18e4bfdb7c4c01, 0x0, 0xc0001ec050, 0x1d99100, 0xc00021aa20)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/crd/gen.go:79 +0x1dc
sigs.k8s.io/controller-tools/pkg/genall.(*Runtime).Run(0xc0007b9080, 0xc0001ec140)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/pkg/genall/genall.go:167 +0x16f
main.main.func1(0xc000200500, 0xc0001ec140, 0x5, 0x5, 0x0, 0x0)
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/cmd/controller-gen/main.go:168 +0x99
github.com/spf13/cobra.(*Command).execute(0xc000200500, 0xc0000200d0, 0x5, 0x5, 0xc000200500, 0xc0000200d0)
        /Users/james/go/pkg/mod/github.com/spf13/[email protected]/command.go:762 +0x460
github.com/spf13/cobra.(*Command).ExecuteC(0xc000200500, 0xc0001c45c0, 0x4, 0x0)
        /Users/james/go/pkg/mod/github.com/spf13/[email protected]/command.go:852 +0x2ea
github.com/spf13/cobra.(*Command).Execute(...)
        /Users/james/go/pkg/mod/github.com/spf13/[email protected]/command.go:800
main.main()
        /Users/james/go/pkg/mod/sigs.k8s.io/[email protected]/cmd/controller-gen/main.go:191 +0x2f5
make: *** [manifests] Error 2

The panic occurs whether or not the struct contains any fields. When the struct is removed, make manifests succeeds as expected.

For an example of nested anonymous structs in use, check out https://medium.com/@xcoulon/nested-structs-in-golang-2c750403a007.

[fejta-bot]

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[k8s-ci-robot]

@fejta-bot: Closing this issue.

In response to this:

Rotten issues close after 30d of inactivity.
Reopen the issue with /reopen.
Mark the issue as fresh with /remove-lifecycle rotten.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/close

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