Implement minimum MySQL version validation (#169)

Resolves: #163

Gopkg.toml

@@ -73,6 +73,10 @@ required = [
   branch = "master"
   name = "github.com/heptiolabs/healthcheck"
 
+[[constraint]]
+  name = "github.com/coreos/go-semver"
+  revision = "e214231b295a8ea9479f11b70b35d5acf3556d9b"
+
 # gengo needs to be manually pinned to the version listed in code-generators
 # Gopkg.toml, because the k8s project does not produce Gopkg.toml files & dep
 # does not parse the Godeps.json file to determine revisions to use.

pkg/apis/mysql/v1alpha1/cluster_test.go

@@ -15,26 +15,51 @@
 package v1alpha1
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/validation/field"
 )
 
-func TestValidVersion(t *testing.T) {
-	for _, version := range validVersions {
-		errList := validateVersion(version, field.NewPath("spec", "version"))
-		if len(errList) > 0 {
-			t.Fail()
-		}
+func TestValidateVersion(t *testing.T) {
+	fldPath := field.NewPath("spec", "version")
+	testCases := map[string]struct {
+		name     string
+		version  string
+		expected field.ErrorList
+	}{
+		"minimum_version_valid": {
+			version:  MinimumMySQLVersion,
+			expected: field.ErrorList{},
+		},
+		"next_patch_version_valid": {
+			version:  "8.0.12",
+			expected: field.ErrorList{},
+		},
+		"next_minor_version_valid": {
+			version:  "8.1.0",
+			expected: field.ErrorList{},
+		},
+		"previous_version_invalid": {
+			version: "8.0.4",
+			expected: field.ErrorList{
+				field.Invalid(fldPath, "8.0.4", fmt.Sprintf("minimum supported MySQL version is %s", MinimumMySQLVersion)),
+			},
+		},
+		"5.7_version_invalid": {
+			version: "5.7.20-1.1.2",
+			expected: field.ErrorList{
+				field.Invalid(fldPath, "5.7.20-1.1.2", fmt.Sprintf("minimum supported MySQL version is %s", MinimumMySQLVersion)),
+			},
+		},
 	}
-}
-
-func TestInvalidVersion(t *testing.T) {
-	err := validateVersion("1.2.3", field.NewPath("spec", "version"))
-	if err == nil {
-		t.Fail()
+	for name, tc := range testCases {
+		t.Run(name, func(t *testing.T) {
+			errs := validateVersion(tc.version, fldPath)
+			assert.EqualValues(t, errs, tc.expected)
+		})
 	}
 }
 

pkg/apis/mysql/v1alpha1/helpers.go

@@ -40,13 +40,6 @@ const (
 	ClusterNameMaxLen = 28
 )
 
-// TODO (owain) we need to remove this because it's not reasonable for us to maintain a list
-// of all the potential MySQL versions that can be used and in reality, it shouldn't matter
-// too much. The burden of this is not worth the benfit to a user
-var validVersions = []string{
-	defaultVersion,
-}
-
 // setOperatorVersionLabel sets the specified operator version label on the label map.
 func setOperatorVersionLabel(labelMap map[string]string, label string) {
 	labelMap[constants.MySQLOperatorVersionLabel] = label

pkg/apis/mysql/v1alpha1/types.go

@@ -19,6 +19,10 @@ import (
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
+// MinimumMySQLVersion is the minimum version of MySQL server supported by the
+// MySQL Operator.
+const MinimumMySQLVersion = "8.0.11"
+
 // ClusterSpec defines the attributes a user can specify when creating a cluster
 type ClusterSpec struct {
 	// Version defines the MySQL Docker image version.

pkg/apis/mysql/v1alpha1/validation.go

@@ -18,9 +18,12 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/oracle/mysql-operator/pkg/constants"
+	"github.com/coreos/go-semver/semver"
+
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/validation/field"
+
+	"github.com/oracle/mysql-operator/pkg/constants"
 )
 
 func validateCluster(c *Cluster) field.ErrorList {
@@ -67,12 +70,23 @@ func validateClusterStatus(s ClusterStatus, fldPath *field.Path) field.ErrorList
 
 func validateVersion(version string, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
-	for _, validVersion := range validVersions {
-		if version == validVersion {
-			return allErrs
+	min, err := semver.NewVersion(MinimumMySQLVersion)
+	if err != nil {
+		allErrs = append(allErrs, field.InternalError(fldPath, fmt.Errorf("unable to parse minimum MySQL version: %v", err)))
+	}
+
+	given, err := semver.NewVersion(version)
+	if err != nil {
+		allErrs = append(allErrs, field.Invalid(fldPath, version, fmt.Sprintf("unable to parse MySQL version: %v", err)))
+	}
+
+	if len(allErrs) == 0 {
+		if given.Compare(*min) == -1 {
+			allErrs = append(allErrs, field.Invalid(fldPath, version, fmt.Sprintf("minimum supported MySQL version is %s", MinimumMySQLVersion)))
 		}
 	}
-	return append(allErrs, field.Invalid(fldPath, version, "invalid version specified"))
+
+	return allErrs
 }
 
 func validateBaseServerID(baseServerID uint32, fldPath *field.Path) field.ErrorList {