ovirt: Add basic engine URL validation

Add a basic URL validator to avoid adding urls with no
scheme or scheme different from https

Signed-off-by: Roberto Ciatti <rciatti@redhat.com>

pkg/asset/installconfig/ovirt/credentials.go

@@ -16,7 +16,7 @@ func askCredentials() (Config, error) {
 				Message: "oVirt API endpoint URL",
 				Help:    "The URL of the oVirt engine API. For example, https://ovirt-engine-fqdn/ovirt-engine/api.",
 			},
-			Validate: survey.ComposeValidators(survey.Required),
+			Validate: survey.ComposeValidators(survey.Required, validURL),
 		},
 	}, &c.URL)
 	if err != nil {

pkg/asset/installconfig/ovirt/validaton.go

@@ -2,6 +2,8 @@ package ovirt
 
 import (
 	"fmt"
+	"net/url"
+	"reflect"
 
 	ovirtsdk "github.com/ovirt/go-ovirt"
 	"github.com/pkg/errors"
@@ -125,3 +127,19 @@ func validateVNICProfile(platform ovirt.Platform, con *ovirtsdk.Connection) erro
 	}
 	return nil
 }
+
+func validURL(val interface{}) error {
+	if urlStr, ok := val.(string); ok {
+		url, err := url.ParseRequestURI(urlStr)
+		if err != nil {
+			return errors.Errorf("The specified URL is invalid, got %s", urlStr)
+		}
+
+		if url.Scheme != "https" {
+			return errors.Errorf("The only URL scheme accepted is https, but got %s", url.Scheme)
+		}
+	} else {
+		return fmt.Errorf("cannot check url validity on type %v", reflect.TypeOf(val).Name())
+	}
+	return nil
+}

pkg/asset/installconfig/ovirt/validaton_test.go

@@ -83,3 +83,36 @@ func Test_validateAuth(t *testing.T) {
 func CreateMockOvirtServer(handler http.HandlerFunc) *httptest.Server {
 	return httptest.NewServer(handler)
 }
+
+func Test_validateURL(t *testing.T) {
+	tests := []struct {
+		url           string
+		expectSuccess bool
+	}{
+		{
+			url:           "engine.example.com",
+			expectSuccess: false,
+		},
+		{
+			url:           "ftp://engine.example.com",
+			expectSuccess: false,
+		},
+		{
+			url:           "http://engine.example.com",
+			expectSuccess: false,
+		},
+		{
+			url:           "https://engine.example.com",
+			expectSuccess: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.url, func(t *testing.T) {
+			got := validURL(tt.url)
+
+			assert.Equal(t, tt.expectSuccess, got == nil, "got this %s", got)
+			t.Log(got)
+		})
+	}
+}