make test failing if --plural flag is provided as capitalized

[prafull01]

What did you do:

Create a api with --plural flag and provide it as capitalized, then it breaks the make test all as the same capitalized plural flag goes into the CRD.

prafull@EMPID18004:~/go/src/github.com/prafull01/kubebuilder/testproj$ ../bin/kubebuilder create api --group=praf --kind=Fernandez --version=v1 --plural=Fernandezes
Create Resource [y/n]
y
Create Controller [y/n]
y
Writing scaffold for you to edit...
api/v1/fernandez_types.go
controllers/fernandez_controller.go
Running make:
$ make
/home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/bin/controller-gen object:headerFile="hack/boilerplate.go.txt" paths="./..."
go fmt ./...
go vet ./...
go build -o bin/manager main.go
prafull@EMPID18004:~/go/src/github.com/prafull01/kubebuilder/testproj$ vi PROJECT 
prafull@EMPID18004:~/go/src/github.com/prafull01/kubebuilder/testproj$ make test all
/home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/bin/controller-gen object:headerFile="hack/boilerplate.go.txt" paths="./..."
go fmt ./...
go vet ./...
/home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/bin/controller-gen "crd:trivialVersions=true,preserveUnknownFields=false" rbac:roleName=manager-role webhook paths="./..." output:crd:artifacts:config=config/crd/bases
mkdir -p /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin
test -f /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin/setup-envtest.sh || curl -sSLo /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin/setup-envtest.sh https://raw.githubusercontent.com/kubernetes-sigs/controller-runtime/v0.7.0/hack/setup-envtest.sh
source /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin/setup-envtest.sh; fetch_envtest_tools /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin; setup_envtest_env /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/testbin; go test ./... -coverprofile cover.out
/bin/sh: 1: source: not found
/bin/sh: 1: fetch_envtest_tools: not found
/bin/sh: 1: setup_envtest_env: not found
vi con?   	sigs.k8s.io/kubebuilder/v3	[no test files]
?   	sigs.k8s.io/kubebuilder/v3/api/v1	[no test files]
fi	Running Suite: Controller Suite
===============================
Random Seed: 1611401178
Will run 0 of 0 specs

STEP: bootstrapping test environment
2021-01-23T16:56:18.280+0530	DEBUG	controller-runtime.test-env	starting control plane	{"api server flags": []}
2021-01-23T16:56:23.879+0530	DEBUG	controller-runtime.test-env	installing CRDs
2021-01-23T16:56:23.879+0530	DEBUG	controller-runtime.test-env	reading CRDs from path	{"path": "../config/crd/bases"}
2021-01-23T16:56:23.881+0530	DEBUG	controller-runtime.test-env	read CRDs from file	{"file": "praf.my.domain_Fernandezes.yaml"}
2021-01-23T16:56:23.902+0530	DEBUG	controller-runtime.test-env	installing CRD	{"crd": "Fernandezes.praf.my.domain"}
Failure [5.635 seconds]
[BeforeSuite] BeforeSuite 
/home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/controllers/suite_test.go:52

  Unexpected error:
      <*errors.StatusError | 0xc0006445a0>: {
          ErrStatus: {
              TypeMeta: {Kind: "", APIVersion: ""},
              ListMeta: {
                  SelfLink: "",
                  ResourceVersion: "",
                  Continue: "",
                  RemainingItemCount: nil,
              },
              Status: "Failure",
              Message: "CustomResourceDefinition.apiextensions.k8s.io \"Fernandezes.praf.my.domain\" is invalid: [metadata.name: Invalid value: \"Fernandezes.praf.my.domain\": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*'), spec.names.plural: Invalid value: \"Fernandezes\": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')]",
              Reason: "Invalid",
              Details: {
                  Name: "Fernandezes.praf.my.domain",
                  Group: "apiextensions.k8s.io",
                  Kind: "CustomResourceDefinition",
                  UID: "",
                  Causes: [
                      {
                          Type: "FieldValueInvalid",
                          Message: "Invalid value: \"Fernandezes.praf.my.domain\": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*')",
                          Field: "metadata.name",
                      },
                      {
                          Type: "FieldValueInvalid",
                          Message: "Invalid value: \"Fernandezes\": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')",
                          Field: "spec.names.plural",
                      },
                  ],
                  RetryAfterSeconds: 0,
              },
              Code: 422,
          },
      }
      CustomResourceDefinition.apiextensions.k8s.io "Fernandezes.praf.my.domain" is invalid: [metadata.name: Invalid value: "Fernandezes.praf.my.domain": a DNS-1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. 'example.com', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*'), spec.names.plural: Invalid value: "Fernandezes": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')]
  occurred

  /home/prafull/go/src/github.com/prafull01/kubebuilder/testproj/controllers/suite_test.go:62
------------------------------


Ran 0 of 0 Specs in 5.668 seconds
FAIL! -- 0 Passed | 0 Failed | 0 Pending | 0 Skipped
--- FAIL: TestAPIs (5.67s)
FAIL
coverage: 0.0% of statements
FAIL	sigs.k8s.io/kubebuilder/v3/controllers	5.681s
FAIL
make: *** [Makefile:37: test] Error 1

We should lowercase the --plural flag value if provided in capitalized by user.

/kind bug

[Adirio]

We have two options here. Either validate the flag to ensure that it is lowercase, or lowercase it ourselves.

If it was the first flag we validate I would probably go with lowercase it ourselves and print a warning to the user, but the approach followed until now is the other one, validate that the user inputed a lowercased string.

[prafull01]

IMO, we should lower it ourselves because the input of --kind is Capitalized like Admiral, so in most probable human scenario is user is going to provide the --plural flag as capitalized also like Admirales. This means throwing the error in most of the cases and ask user to provide it as lowercase value.

[Adirio]

That has a really simple solution, press up arrow, remove the capital, press enter. Same happens if you provide --kind admiral, it will error out. Kept the same behavior in my PR.

[camilamacedo86]

Hi @prafull01,

the #1970 makes sense for me. Since it is the small fix we can get it merged. However, please feel free to re-open this one or raise a new one and any PR with your suggestions to improve/fix it as well.