chore(golang): refactor go version check for per-plugin configuration

Signed-off-by: Eric Stroczynski <[email protected]>

Author: estroz

pkg/plugins/golang/go_version.go

@@ -29,25 +29,34 @@ const (
 )
 
 var (
-	go113 = goVersion{
-		major: 1,
-		minor: 13,
-	}
-	goVerMax = goVersion{
-		major:      1,
-		minor:      17,
-		prerelease: "alpha1",
-	}
-
 	goVerRegexp = regexp.MustCompile(goVerPattern)
 )
 
-type goVersion struct {
+// GoVersion describes a Go version.
+type GoVersion struct {
 	major, minor, patch int
 	prerelease          string
 }
 
-func (v *goVersion) parse(verStr string) error {
+func (v GoVersion) String() string {
+	switch {
+	case v.patch != 0:
+		return fmt.Sprintf("go%d.%d.%d", v.major, v.minor, v.patch)
+	case v.prerelease != "":
+		return fmt.Sprintf("go%d.%d%s", v.major, v.minor, v.prerelease)
+	}
+	return fmt.Sprintf("go%d.%d", v.major, v.minor)
+}
+
+// MustParse will panic if verStr does not match the expected Go version string spec.
+func MustParse(verStr string) (v GoVersion) {
+	if err := v.parse(verStr); err != nil {
+		panic(err)
+	}
+	return v
+}
+
+func (v *GoVersion) parse(verStr string) error {
 	m := goVerRegexp.FindStringSubmatch(verStr)
 	if m == nil {
 		return fmt.Errorf("invalid version string")
@@ -77,7 +86,8 @@ func (v *goVersion) parse(verStr string) error {
 	return nil
 }
 
-func (v goVersion) compare(other goVersion) int {
+// Compare returns -1, 0, or 1 if v < other, v == other, or v > other, respectively.
+func (v GoVersion) Compare(other GoVersion) int {
 	if v.major > other.major {
 		return 1
 	}
@@ -114,16 +124,16 @@ func (v goVersion) compare(other goVersion) int {
 	return -1
 }
 
-// ValidateGoVersion verifies that Go is installed and the current go version is supported by kubebuilder
-func ValidateGoVersion() error {
-	err := fetchAndCheckGoVersion()
+// ValidateGoVersion verifies that Go is installed and the current go version is supported by a plugin.
+func ValidateGoVersion(min, max GoVersion) error {
+	err := fetchAndCheckGoVersion(min, max)
 	if err != nil {
 		return fmt.Errorf("%s. You can skip this check using the --skip-go-version-check flag", err)
 	}
 	return nil
 }
 
-func fetchAndCheckGoVersion() error {
+func fetchAndCheckGoVersion(min, max GoVersion) error {
 	cmd := exec.Command("go", "version")
 	out, err := cmd.Output()
 	if err != nil {
@@ -135,22 +145,20 @@ func fetchAndCheckGoVersion() error {
 		return fmt.Errorf("found invalid Go version: %q", string(out))
 	}
 	goVer := split[2]
-	if err := checkGoVersion(goVer); err != nil {
+	if err := checkGoVersion(goVer, min, max); err != nil {
 		return fmt.Errorf("go version '%s' is incompatible because '%s'", goVer, err)
 	}
 	return nil
 }
 
-// checkGoVersion should only ever check if the Go version >= 1.13, since the kubebuilder binary only cares
-// that the go binary supports go modules which were stabilized in that version (i.e. in go 1.13) by default
-func checkGoVersion(verStr string) error {
-	var version goVersion
+func checkGoVersion(verStr string, min, max GoVersion) error {
+	var version GoVersion
 	if err := version.parse(verStr); err != nil {
 		return err
 	}
 
-	if version.compare(go113) < 0 || version.compare(goVerMax) >= 0 {
-		return fmt.Errorf("requires 1.13 <= version < 1.17")
+	if version.Compare(min) < 0 || version.Compare(max) >= 0 {
+		return fmt.Errorf("plugin requires %s <= version < %s", min, max)
 	}
 
 	return nil

pkg/plugins/golang/go_version_test.go

@@ -24,42 +24,42 @@ import (
 	. "github.com/onsi/gomega"
 )
 
-var _ = Describe("goVersion", func() {
+var _ = Describe("GoVersion", func() {
 	Context("parse", func() {
-		var v goVersion
+		var v GoVersion
 
 		BeforeEach(func() {
-			v = goVersion{}
+			v = GoVersion{}
 		})
 
 		DescribeTable("should succeed for valid versions",
-			func(version string, expected goVersion) {
+			func(version string, expected GoVersion) {
 				Expect(v.parse(version)).NotTo(HaveOccurred())
 				Expect(v.major).To(Equal(expected.major))
 				Expect(v.minor).To(Equal(expected.minor))
 				Expect(v.patch).To(Equal(expected.patch))
 				Expect(v.prerelease).To(Equal(expected.prerelease))
 			},
-			Entry("for minor release", "go1.15", goVersion{
+			Entry("for minor release", "go1.15", GoVersion{
 				major: 1,
 				minor: 15,
 			}),
-			Entry("for patch release", "go1.15.1", goVersion{
+			Entry("for patch release", "go1.15.1", GoVersion{
 				major: 1,
 				minor: 15,
 				patch: 1,
 			}),
-			Entry("for alpha release", "go1.15alpha1", goVersion{
+			Entry("for alpha release", "go1.15alpha1", GoVersion{
 				major:      1,
 				minor:      15,
 				prerelease: "alpha1",
 			}),
-			Entry("for beta release", "go1.15beta1", goVersion{
+			Entry("for beta release", "go1.15beta1", GoVersion{
 				major:      1,
 				minor:      15,
 				prerelease: "beta1",
 			}),
-			Entry("for release candidate", "go1.15rc1", goVersion{
+			Entry("for release candidate", "go1.15rc1", GoVersion{
 				major:      1,
 				minor:      15,
 				prerelease: "rc1",
@@ -78,10 +78,10 @@ var _ = Describe("goVersion", func() {
 		)
 	})
 
-	Context("compare", func() {
-		// Test compare() by sorting a list.
+	Context("Compare", func() {
+		// Test Compare() by sorting a list.
 		var (
-			versions = []goVersion{
+			versions = []GoVersion{
 				{major: 1, minor: 15, prerelease: "rc2"},
 				{major: 1, minor: 15, patch: 1},
 				{major: 1, minor: 16},
@@ -98,7 +98,7 @@ var _ = Describe("goVersion", func() {
 				{major: 0, minor: 123},
 			}
 
-			sortedVersions = []goVersion{
+			sortedVersions = []GoVersion{
 				{major: 0, minor: 123},
 				{major: 1, minor: 13},
 				{major: 1, minor: 14},
@@ -118,16 +118,19 @@ var _ = Describe("goVersion", func() {
 
 		It("sorts a valid list of versions correctly", func() {
 			sort.Slice(versions, func(i int, j int) bool {
-				return versions[i].compare(versions[j]) == -1
+				return versions[i].Compare(versions[j]) == -1
 			})
 			Expect(versions).To(Equal(sortedVersions))
 		})
 	})
 })
 
 var _ = Describe("checkGoVersion", func() {
-	DescribeTable("should return true for supported go versions",
-		func(version string) { Expect(checkGoVersion(version)).NotTo(HaveOccurred()) },
+	goVerMin := MustParse("go1.13")
+	goVerMax := MustParse("go2.0alpha1")
+
+	DescribeTable("should return no error for supported go versions",
+		func(version string) { Expect(checkGoVersion(version, goVerMin, goVerMax)).To(Succeed()) },
 		Entry("for go 1.13", "go1.13"),
 		Entry("for go 1.13.1", "go1.13.1"),
 		Entry("for go 1.13.2", "go1.13.2"),
@@ -181,11 +184,13 @@ var _ = Describe("checkGoVersion", func() {
 		Entry("for go 1.16.4", "go1.16.4"),
 	)
 
-	DescribeTable("should return false for non-supported go versions",
-		func(version string) { Expect(checkGoVersion(version)).To(HaveOccurred()) },
+	DescribeTable("should return an error for non-supported go versions",
+		func(version string) { Expect(checkGoVersion(version, goVerMin, goVerMax)).NotTo(Succeed()) },
 		Entry("for invalid go versions", "go"),
 		Entry("for go 1.13beta1", "go1.13beta1"),
 		Entry("for go 1.13rc1", "go1.13rc1"),
 		Entry("for go 1.13rc2", "go1.13rc2"),
+		Entry("for go 2.0alpha1", "go2.0alpha1"),
+		Entry("for go 2.0.0", "go2.0.0"),
 	)
 })

pkg/plugins/golang/v2/init.go

@@ -34,6 +34,12 @@ import (
 	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/v2/scaffolds"
 )
 
+// Variables and function to check Go version requirements.
+var (
+	goVerMin = golang.MustParse("go1.13")
+	goVerMax = golang.MustParse("go2.0alpha1")
+)
+
 var _ plugin.InitSubcommand = &initSubcommand{}
 
 type initSubcommand struct {
@@ -134,9 +140,9 @@ func (p *initSubcommand) InjectConfig(c config.Config) error {
 }
 
 func (p *initSubcommand) PreScaffold(machinery.Filesystem) error {
-	// Validate the supported go versions
+	// Ensure Go version is in the allowed range if check not turned off.
 	if !p.skipGoVersionCheck {
-		if err := golang.ValidateGoVersion(); err != nil {
+		if err := golang.ValidateGoVersion(goVerMin, goVerMax); err != nil {
 			return err
 		}
 	}

pkg/plugins/golang/v3/init.go

@@ -33,6 +33,12 @@ import (
 	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/v3/scaffolds"
 )
 
+// Variables and function to check Go version requirements.
+var (
+	goVerMin = golang.MustParse("go1.16")
+	goVerMax = golang.MustParse("go2.0alpha1")
+)
+
 var _ plugin.InitSubcommand = &initSubcommand{}
 
 type initSubcommand struct {
@@ -106,9 +112,9 @@ func (p *initSubcommand) InjectConfig(c config.Config) error {
 }
 
 func (p *initSubcommand) PreScaffold(machinery.Filesystem) error {
-	// Requires go1.11+
+	// Ensure Go version is in the allowed range if check not turned off.
 	if !p.skipGoVersionCheck {
-		if err := golang.ValidateGoVersion(); err != nil {
+		if err := golang.ValidateGoVersion(goVerMin, goVerMax); err != nil {
 			return err
 		}
 	}