feat: cluster cache should expose synchronization error (argoproj#32)

SeldonIO · May 18, 2020 · 9163758 · 9163758
1 parent 8430dc0
commit 9163758
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Showing 2 changed files with 48 additions and 4 deletions.
diff --git a/codecov.yml b/codecov.yml
@@ -0,0 +1,6 @@
+coverage:
+  status:
+    patch: off
+    project:
+      default:
+        threshold: 2
diff --git a/pkg/utils/kube/cache/cluster.go b/pkg/utils/kube/cache/cluster.go
@@ -38,12 +38,20 @@ type apiMeta struct {
 	watchCancel     context.CancelFunc
 }
 
+// ClusterInfo holds cluster cache stats
 type ClusterInfo struct {
-	Server            string
-	K8SVersion        string
-	ResourcesCount    int
-	APIsCount         int
+	// Server holds cluster API server URL
+	Server string
+	// K8SVersion holds Kubernetes version
+	K8SVersion string
+	// ResourcesCount holds number of observed Kubernetes resources
+	ResourcesCount int
+	// APIsCount holds number of observed Kubernetes API count
+	APIsCount int
+	// LastCacheSyncTime holds time of most recent cache synchronization
 	LastCacheSyncTime *time.Time
+	// SyncError holds most recent cache synchronization error
+	SyncError error
 }
 
 type Settings struct {
@@ -59,20 +67,35 @@ type OnResourceUpdatedHandler func(newRes *Resource, oldRes *Resource, namespace
 type Unsubscribe func()
 
 type ClusterCache interface {
+	// EnsureSynced checks cache state and synchronizes it if necessary
 	EnsureSynced() error
+	// GetServerVersion returns observed cluster version
 	GetServerVersion() string
+	// GetAPIGroups returns information about observed API groups
 	GetAPIGroups() []metav1.APIGroup
+	// Invalidate cache and executes callback that optionally might update cache settings
 	Invalidate(settingsCallback func(*rest.Config, []string, Settings) (*rest.Config, []string, Settings))
+	// GetNamespaceTopLevelResources returns top level resources in the specified namespace
 	GetNamespaceTopLevelResources(namespace string) map[kube.ResourceKey]*Resource
+	// IterateHierarchy iterates resource tree starting from the specified top level resource and executes callback for each resource in the tree
 	IterateHierarchy(key kube.ResourceKey, action func(resource *Resource, namespaceResources map[kube.ResourceKey]*Resource))
+	// IsNamespaced answers if specified group/kind is a namespaced resource API or not
 	IsNamespaced(gk schema.GroupKind) (bool, error)
+	// GetManagedLiveObjs helps finding matching live K8S resources for a given resources list.
+	// The function returns all resources from cache for those `isManaged` function returns true and resources
+	// specified in targetObjs list.
 	GetManagedLiveObjs(targetObjs []*unstructured.Unstructured, isManaged func(r *Resource) bool) (map[kube.ResourceKey]*unstructured.Unstructured, error)
+	// GetClusterInfo returns cluster cache statistics
 	GetClusterInfo() ClusterInfo
+	// SetPopulateResourceInfoHandler sets callback that populates resource information in the cache
 	SetPopulateResourceInfoHandler(handler OnPopulateResourceInfoHandler)
+	// OnResourceUpdated register event handler that is executed every time when resource get's updated in the cache
 	OnResourceUpdated(handler OnResourceUpdatedHandler) Unsubscribe
+	// OnEvent register event handler that is executed every time when new K8S event received
 	OnEvent(handler OnEventHandler) Unsubscribe
 }
 
+// NewClusterCache creates new instance of cluster cache
 func NewClusterCache(settings Settings, config *rest.Config, namespaces []string, kubectl kube.Kubectl) *clusterCache {
 	return &clusterCache{
 		settings:                settings,
@@ -115,12 +138,14 @@ type clusterCache struct {
 	eventHandlers               map[uint64]OnEventHandler
 }
 
+// SetPopulateResourceInfoHandler sets callback that populates resource information in the cache
 func (c *clusterCache) SetPopulateResourceInfoHandler(handler OnPopulateResourceInfoHandler) {
 	c.handlersLock.Lock()
 	defer c.handlersLock.Unlock()
 	c.populateResourceInfoHandler = handler
 }
 
+// OnResourceUpdated register event handler that is executed every time when resource get's updated in the cache
 func (c *clusterCache) OnResourceUpdated(handler OnResourceUpdatedHandler) Unsubscribe {
 	c.handlersLock.Lock()
 	defer c.handlersLock.Unlock()
@@ -143,6 +168,7 @@ func (c *clusterCache) getResourceUpdatedHandlers() []OnResourceUpdatedHandler {
 	return handlers
 }
 
+// OnEvent register event handler that is executed every time when new K8S event received
 func (c *clusterCache) OnEvent(handler OnEventHandler) Unsubscribe {
 	c.handlersLock.Lock()
 	defer c.handlersLock.Unlock()
@@ -165,10 +191,12 @@ func (c *clusterCache) getEventHandlers() []OnEventHandler {
 	return handlers
 }
 
+// GetServerVersion returns observed cluster version
 func (c *clusterCache) GetServerVersion() string {
 	return c.serverVersion
 }
 
+// GetAPIGroups returns information about observed API groups
 func (c *clusterCache) GetAPIGroups() []metav1.APIGroup {
 	return c.apiGroups
 }
@@ -285,6 +313,7 @@ func (c *clusterCache) setNode(n *Resource) {
 	ns[key] = n
 }
 
+// Invalidate cache and executes callback that optionally might update cache settings
 func (c *clusterCache) Invalidate(settingsCallback func(*rest.Config, []string, Settings) (*rest.Config, []string, Settings)) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
@@ -553,6 +582,7 @@ func (c *clusterCache) sync() (err error) {
 	return nil
 }
 
+// EnsureSynced checks cache state and synchronizes it if necessary
 func (c *clusterCache) EnsureSynced() error {
 	// first check if cluster is synced *without lock*
 	if c.synced() {
@@ -573,6 +603,7 @@ func (c *clusterCache) EnsureSynced() error {
 	return c.syncError
 }
 
+// GetNamespaceTopLevelResources returns top level resources in the specified namespace
 func (c *clusterCache) GetNamespaceTopLevelResources(namespace string) map[kube.ResourceKey]*Resource {
 	c.lock.RLock()
 	defer c.lock.RUnlock()
@@ -585,6 +616,7 @@ func (c *clusterCache) GetNamespaceTopLevelResources(namespace string) map[kube.
 	return resources
 }
 
+// IterateHierarchy iterates resource tree starting from the specified top level resource and executes callback for each resource in the tree
 func (c *clusterCache) IterateHierarchy(key kube.ResourceKey, action func(resource *Resource, namespaceResources map[kube.ResourceKey]*Resource)) {
 	c.lock.Lock()
 	defer c.lock.Unlock()
@@ -615,13 +647,17 @@ func (c *clusterCache) IterateHierarchy(key kube.ResourceKey, action func(resour
 	}
 }
 
+// IsNamespaced answers if specified group/kind is a namespaced resource API or not
 func (c *clusterCache) IsNamespaced(gk schema.GroupKind) (bool, error) {
 	if isNamespaced, ok := c.namespacedResources[gk]; ok {
 		return isNamespaced, nil
 	}
 	return false, errors.NewNotFound(schema.GroupResource{Group: gk.Group}, "")
 }
 
+// GetManagedLiveObjs helps finding matching live K8S resources for a given resources list.
+// The function returns all resources from cache for those `isManaged` function returns true and resources
+// specified in targetObjs list.
 func (c *clusterCache) GetManagedLiveObjs(targetObjs []*unstructured.Unstructured, isManaged func(r *Resource) bool) (map[kube.ResourceKey]*unstructured.Unstructured, error) {
 	c.lock.RLock()
 	defer c.lock.RUnlock()
@@ -748,6 +784,7 @@ var (
 	}
 )
 
+// GetClusterInfo returns cluster cache statistics
 func (c *clusterCache) GetClusterInfo() ClusterInfo {
 	c.lock.RLock()
 	defer c.lock.RUnlock()
@@ -757,6 +794,7 @@ func (c *clusterCache) GetClusterInfo() ClusterInfo {
 		ResourcesCount:    len(c.resources),
 		Server:            c.config.Host,
 		LastCacheSyncTime: c.syncTime,
+		SyncError:         c.syncError,
 	}
 }