Container names must end with an alphanumeric character

pkg/names/generate.go

@@ -18,8 +18,8 @@ package names
 
 import (
 	"fmt"
-
 	utilrand "k8s.io/apimachinery/pkg/util/rand"
+	"regexp"
 )
 
 // NameGenerator generates names for objects. Some backends may have more information
@@ -61,5 +61,10 @@ func (simpleNameGenerator) RestrictLength(base string) string {
 	if len(base) > maxNameLength {
 		base = base[:maxNameLength]
 	}
+	var isLetter = regexp.MustCompile(`^[a-zA-Z]+$`).MatchString
+
+	for !isLetter(base[len(base)-1:]) {
+		base = base[:len(base)-1]
+	}
 	return base
 }

pkg/reconciler/v1alpha1/taskrun/resources/pod_test.go

@@ -179,7 +179,7 @@ func TestMakePod(t *testing.T) {
 		desc: "very-long-step-name",
 		b: v1alpha1.BuildSpec{
 			Steps: []corev1.Container{{
-				Name:  "a-sixty-three-character-step-name-to-trigger-max-length-checkxx",
+				Name:  "a-very-long-character-step-name-to-trigger-max-len----and-invalid-characters",
 				Image: "image",
 			}},
 		},
@@ -196,7 +196,7 @@ func TestMakePod(t *testing.T) {
 				VolumeMounts: implicitVolumeMounts,
 				WorkingDir:   workspaceDir,
 			}, {
-				Name:         "build-step-a-sixty-three-character-step-name-to-trigger-max-len",
+				Name:         "build-step-a-very-long-character-step-name-to-trigger-max-len",
 				Image:        "image",
 				Env:          implicitEnvVars,
 				VolumeMounts: implicitVolumeMounts,