Harden pod chooser for no running pods

CONTRIBUTING.md

@@ -39,6 +39,7 @@ If you want to run a single suite of tests while working on a specific area of t
 ```
 make integration EXTRA_GO_TEST_FLAGS="-run TestConfigMapSuite -v"
 ```
+Hint: find the current test suites with `grep "func Test" integration/suites/*.go`
 
 To check your code for **lint/style consistency**, run
 ```

README.md

@@ -117,7 +117,7 @@ kubectl apply -f ./examples/local-registry.yaml
 kubectl buildkit create --config ./examples/local-registry-buildkitd.toml
 ```
 
-You can then build using the registry cache with something like
+You can then build using the registry cache with the command:
 ```
 kubectl build -t myimage --cache-to=type=registry,ref=registry:5000/cache --cache-from=type=registry,ref=registry:5000/cache .
 ```

pkg/driver/kubernetes/driver.go

@@ -22,6 +22,7 @@ import (
 	"github.com/vmware-tanzu/buildkit-cli-for-kubectl/pkg/store"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
+	kubeerrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 	clientappsv1 "k8s.io/client-go/kubernetes/typed/apps/v1"
@@ -80,9 +81,11 @@ func (d *Driver) Bootstrap(ctx context.Context, l progress.Logger) error {
 	return progress.Wrap("[internal] booting buildkit", l, func(sub progress.SubLogger) error {
 		_, err := d.configMapClient.Get(ctx, d.configMap.Name, metav1.GetOptions{})
 
-		if err != nil {
+		if err != nil && kubeerrors.IsNotFound(err) {
 			// Doesn't exist, create it
 			_, err = d.configMapClient.Create(ctx, d.configMap, metav1.CreateOptions{})
+		} else if err != nil {
+			return errors.Wrapf(err, "configmap get error for %q", d.configMap.Name)
 		} else if d.userSpecifiedConfig {
 			// err was nil, thus it already exists, and user passed a new config, so update it
 			_, err = d.configMapClient.Update(ctx, d.configMap, metav1.UpdateOptions{})
@@ -273,11 +276,11 @@ func (d *Driver) wait(ctx context.Context, sub progress.SubLogger) error {
 						if err != nil {
 							return err
 						}
-						// Instead of updating, we'll just delete and re-create
-						err = d.Rm(ctx, true)
-						if err != nil {
-							return err
+						// Instead of updating, we'll just delete the deployment and re-create
+						if err := d.deploymentClient.Delete(ctx, d.deployment.Name, metav1.DeleteOptions{}); err != nil {
+							return errors.Wrapf(err, "error while calling deploymentClient.Delete for %q", d.deployment.Name)
 						}
+
 						// Wait for the pods to wind down before re-deploying...
 						for ; try < 100; try++ {
 							remainingPods := 0

pkg/driver/kubernetes/podchooser/podchooser.go

@@ -4,6 +4,7 @@ package podchooser
 
 import (
 	"context"
+	"fmt"
 	"math/rand"
 	"sort"
 	"time"
@@ -31,6 +32,9 @@ func (pc *RandomPodChooser) ChoosePod(ctx context.Context) (*corev1.Pod, error)
 	if err != nil {
 		return nil, err
 	}
+	if len(pods) == 0 {
+		return nil, fmt.Errorf("no builder pods are running")
+	}
 	randSource := pc.RandSource
 	if randSource == nil {
 		randSource = rand.NewSource(time.Now().Unix())