fix(k8s): error with missing metadata field

This should fix a user-reported error of

```
Cannot read property 'namespace' of undefined
```

which is most likely due to an assumption of a metadata field existing
on a resource.

There may be a further underlying error, but this should at the very
least reveal what that is.

core/src/plugins/kubernetes/api.ts

@@ -476,7 +476,7 @@ export class KubeApi {
     }
 
     if (!namespace) {
-      namespace = manifest.metadata.namespace
+      namespace = manifest.metadata?.namespace
     }
 
     if (!namespace) {

core/src/plugins/kubernetes/kubernetes-module/common.ts

@@ -39,7 +39,11 @@ export async function getManifests({
 
   return Bluebird.map(manifests, async (manifest) => {
     // Ensure a namespace is set, if not already set, and if required by the resource type
-    if (!manifest.metadata.namespace) {
+    if (!manifest.metadata?.namespace) {
+      if (!manifest.metadata) {
+        manifest.metadata = {}
+      }
+
       try {
         const info = await api.getApiResourceInfo(log, manifest.apiVersion, manifest.kind)
 

core/src/plugins/kubernetes/logs.ts

@@ -87,7 +87,7 @@ async function readLogsFromApi({
 
   const logs = await getPodLogs({
     api,
-    namespace: pod.metadata.namespace || defaultNamespace,
+    namespace: pod.metadata?.namespace || defaultNamespace,
     pod,
     lineLimit: tail === -1 ? undefined : tail,
     timestamps: true,
@@ -137,7 +137,7 @@ async function followLogs({
 }) {
   const sternArgs = [
     `--context=${provider.config.context}`,
-    `--namespace=${pod.metadata.namespace || defaultNamespace}`,
+    `--namespace=${pod.metadata?.namespace || defaultNamespace}`,
     `--exclude-container=garden-*`,
     "--tail",
     String(tail),

core/src/plugins/kubernetes/namespace.ts

@@ -229,7 +229,7 @@ export async function getModuleNamespace({
   return getNamespace({
     log,
     ctx,
-    override: module.spec.namespace ? { name: module.spec.namespace } : undefined,
+    override: module.spec?.namespace ? { name: module.spec.namespace } : undefined,
     provider,
     skipCreate,
   })

core/src/plugins/kubernetes/status/events.ts

@@ -15,7 +15,7 @@ export async function getResourceEvents(api: KubeApi, resource: KubernetesResour
     `involvedObject.kind=${resource.kind},` +
     `involvedObject.name=${resource.metadata.name}`
 
-  const namespace = resource.metadata.namespace
+  const namespace = resource.metadata?.namespace
 
   const res = namespace
     ? await api.core.listNamespacedEvent(namespace, undefined, undefined, undefined, fieldSelector)

core/src/plugins/kubernetes/status/service.ts

@@ -40,7 +40,7 @@ export async function waitForServiceEndpoints(
     }
 
     const serviceName = service.metadata.name
-    const serviceNamespace = service.metadata.namespace || namespace
+    const serviceNamespace = service.metadata?.namespace || namespace
 
     const pods = await getPods(api, serviceNamespace, selector)
     const readyPodNames = pods

core/src/plugins/kubernetes/status/status.ts

@@ -131,7 +131,7 @@ export async function checkResourceStatus(
 ) {
   const handler = objHandlers[manifest.kind]
 
-  if (manifest.metadata.namespace) {
+  if (manifest.metadata?.namespace) {
     namespace = manifest.metadata.namespace
   }
 
@@ -364,7 +364,7 @@ export async function compareDeployedResources(
     manifest.apiVersion = deployedResource.apiVersion
 
     // the namespace property is silently dropped when added to non-namespaced resources
-    if (manifest.metadata.namespace && deployedResource.metadata.namespace === undefined) {
+    if (manifest.metadata?.namespace && deployedResource.metadata?.namespace === undefined) {
       delete manifest.metadata.namespace
     }
 
@@ -420,7 +420,7 @@ export async function getDeployedResource(
   log: LogEntry
 ): Promise<KubernetesResource | null> {
   const api = await KubeApi.factory(log, ctx, provider)
-  const namespace = resource.metadata.namespace || (await getAppNamespace(ctx, log, provider))
+  const namespace = resource.metadata?.namespace || (await getAppNamespace(ctx, log, provider))
 
   try {
     const res = await api.readBySpec({ namespace, manifest: resource, log })

core/src/plugins/kubernetes/util.ts

@@ -61,7 +61,7 @@ export async function getAllPods(
       }
 
       if (isWorkload(resource)) {
-        return getWorkloadPods(api, resource.metadata.namespace || defaultNamespace, <KubernetesWorkload>resource)
+        return getWorkloadPods(api, resource.metadata?.namespace || defaultNamespace, <KubernetesWorkload>resource)
       }
 
       return []
@@ -126,13 +126,13 @@ export async function getCurrentWorkloadPods(api: KubeApi, namespace: string, re
 export async function getWorkloadPods(api: KubeApi, namespace: string, resource: KubernetesWorkload) {
   // We don't match on the garden.io/version label because it can fall out of sync during hot reloads
   const selector = omit(getSelectorFromResource(resource), gardenAnnotationKey("version"))
-  const pods = await getPods(api, resource.metadata.namespace || namespace, selector)
+  const pods = await getPods(api, resource.metadata?.namespace || namespace, selector)
 
   if (resource.kind === "Deployment") {
     // Make sure we only return the pods from the current ReplicaSet
     const selectorString = labelSelectorToString(selector)
     const replicaSetRes = await api.apps.listNamespacedReplicaSet(
-      resource.metadata.namespace || namespace,
+      resource.metadata?.namespace || namespace,
       undefined, // pretty
       undefined, // allowWatchBookmarks
       undefined, // _continue