Fix a bug where certificate generation took sometime

In the cases where `status.certificate` field took sometime
to get populated, because of reasons for example the core
controllers were not ready, we got the empty certificate.
This commit waits to get the certificate field genereated.

pkg/allow/allow.go

@@ -19,12 +19,18 @@ import (
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	apirand "k8s.io/apimachinery/pkg/util/rand"
+	"k8s.io/apimachinery/pkg/util/wait"
 	clientcmdapi "k8s.io/client-go/tools/clientcmd/api"
 
 	"github.com/viveksinghggits/akcess/pkg/kube"
 	"github.com/viveksinghggits/akcess/pkg/utils"
 )
 
+var (
+	certificateWaitTimeout       = 30 * time.Second
+	certificateWaitPollInternval = 1 * time.Second
+)
+
 func Access(o *utils.AllowOptions, id uuid.UUID) error {
 	commonName := fmt.Sprintf("%s-%s", utils.Name, apirand.String(5))
 
@@ -78,6 +84,20 @@ func Access(o *utils.AllowOptions, id uuid.UUID) error {
 		return errors.Wrap(err, "Approving CertificateSigningRequest")
 	}
 
+	// wait for certificate field to be generated in CSR's status.certificate field
+	err = wait.Poll(certificateWaitPollInternval, certificateWaitTimeout, func() (done bool, err error) {
+		csr, err := k.KubeClient.CertificatesV1().CertificateSigningRequests().Get(ctx, c.Name, metav1.GetOptions{})
+		if string(csr.Status.Certificate) != "" {
+			return true, nil
+		}
+
+		return false, nil
+	})
+
+	if err != nil {
+		return errors.Wrap(err, "waiting for CSR certificate to be generated")
+	}
+
 	// create role and rolebinding
 	r, err := kube.RoleObject(o, id)
 	if err != nil {

pkg/kube/kube.go

@@ -27,6 +27,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/rand"
 	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
@@ -93,7 +94,7 @@ func CSRObject(csr []byte, duration int32, id uuid.UUID) *v1.CertificateSigningR
 	durationSeconds := duration * 60
 	csrObject := &v1.CertificateSigningRequest{
 		ObjectMeta: metav1.ObjectMeta{
-			GenerateName: fmt.Sprintf("%s-", utils.Name),
+			Name: fmt.Sprintf("%s-%s", utils.Name, rand.String(5)),
 			Annotations: map[string]string{
 				utils.ResourceAnnotationKey: id.String(),
 			},